KR102400738B1 - A pattern formation method, an ion implantation method, a laminate, a kit, a composition for forming a resist underlayer film, a resist composition, and a manufacturing method of an electronic device - Google Patents

Abstract

According to the present invention, (1) a step of forming a resist underlayer film on a target substrate; (2) on the resist underlayer film, (A) a resin having atoms selected from the group consisting of Si atoms and Ti atoms. A resist composition comprising: (3) exposing the resist film; (4) developing the exposed resist film to form a resist pattern; (5) using the resist pattern as a mask; A pattern forming method comprising a step of forming a pattern by processing a resist underlayer film, wherein the resist underlayer film has a film thickness of 2.5 μm or more and the resist film has a film thickness of 1 μm or less, a pattern forming method, and an ion implantation method using the same; A laminate, a kit, a composition for forming a resist underlayer film, a resist composition, and a method for manufacturing an electronic device used in a pattern forming method are provided.

Description

A pattern formation method, an ion implantation method, a laminate, a kit, a composition for forming a resist underlayer film, a resist composition, and a manufacturing method of an electronic device

The present invention relates to a pattern formation method, an ion implantation method, a laminate, a kit, a composition for forming a resist underlayer film, a resist composition, and a method for manufacturing an electronic device. More specifically, the present invention relates to a pattern formation method, an ion implantation method suitable for a semiconductor manufacturing process such as an IC (Integrated Circuit), manufacturing a circuit board such as a liquid crystal and a thermal head, and other lithography processes for photofabrication. , a laminate, a kit, a composition for forming a resist underlayer film, a resist composition, and a method for manufacturing an electronic device.

DESCRIPTION OF RELATED ART Conventionally, in the manufacturing process of semiconductor devices, such as an IC, microfabrication by lithography using a resist composition is performed, and various pattern formation methods have been proposed.

Although various types of resist compositions are known, those containing a resin having a repeating unit having Si atoms are known as one embodiment.

For example, in Patent Document 1, (1) a step of forming a resist underlayer film on a substrate to be processed; (2) on the resist underlayer film, (A) a resin having a repeating unit containing Si atoms; (B) forming a resist film with a resist composition containing a compound that generates an acid upon irradiation with actinic ray or radiation; (3) exposing the resist film; A pattern comprising: a step of developing using a developer containing a solvent to form a negative resist pattern; and (5) forming a pattern by processing the resist underlayer film and a substrate to be processed using the resist pattern as a mask As a formation method, the content of resin (A) is 20 mass % or more based on the total solid of a resist composition, The pattern formation method is disclosed.

Also, for example, Patent Document 2 discloses a silicon-containing high molecular compound containing a specific repeating unit used for a resist material.

Patent Document 1: International Publication No. 2016/208300 Patent Document 2: Japanese Patent Application Laid-Open No. 2002-256033

By the way, in the manufacturing of a semiconductor device, in the form of implanting ions into the deep part of a board|substrate, ion implantation with respect to the board|substrate whose specific area|region is masked by the resist pattern which has a thick film thickness (for example, 2.5 micrometers or more). It is thought to do

However, when a resist pattern having a thick film thickness and a high degree of fineness is to be formed by exposure and development to the resist film, in the developing process, a resist pattern having a longitudinally long cross-section is There existed a problem that it was easy to collapse by receiving capillary force from a developing solution.

The present invention has been made in view of the above situation, and a pattern forming method capable of forming a pattern with a thick film thickness (eg, 2.5 μm or more) and pattern collapse is unlikely to occur, an ion implantation method using the same, and the pattern It aims at providing the manufacturing method of the laminated body, kit, the composition for resist underlayer film formation, a resist composition, and an electronic device used for a formation method.

That is, the present inventors discovered that the said subject could be solved by the following structures.

〔One〕

(1) forming a resist underlayer film on the target substrate;

(2) forming a resist film on the resist underlayer film by using (A) a resist composition containing a resin having an atom selected from the group consisting of Si atoms and Ti atoms;

(3) exposing the resist film;

(4) developing the exposed resist film to form a resist pattern;

(5) using the resist pattern as a mask, and processing the resist underlayer film to form a pattern;

The film thickness of the said resist underlayer film is 2.5 micrometers or more, and the film thickness of the said resist film is 1 micrometer or less, the pattern formation method.

〔2〕

The pattern forming method according to [1], wherein the resin (A) is a resin having Si atoms.

[3]

The pattern formation method according to [2], wherein the content of Si atoms in the resin (A) is 1 to 30 mass% based on the total amount of the resin (A).

〔4〕

The pattern formation method according to any one of [1] to [3], wherein the resin (A) has a repeating unit having an acid-decomposable group.

[5]

The pattern forming method according to any one of [1] to [4], wherein the resin (A) has at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure.

[6]

The pattern forming method according to any one of [1] to [5], wherein the step (4) is a step of forming a resist pattern by developing the exposed resist film with a developer, and the developer is an alkali developer.

[7]

The pattern forming method according to any one of [1] to [6], wherein in the step (3), the resist film is exposed by any one of KrF exposure, ArF exposure, and ArF immersion exposure.

〔8〕

The pattern forming method according to any one of [1] to [7], wherein the step (5) is a step of forming a pattern by dry etching the resist underlayer film using the resist pattern as a mask.

[9]

The pattern forming method according to [8], wherein the dry etching of the resist underlayer film is oxygen plasma etching.

[10]

The pattern forming method according to any one of [1] to [9], wherein the resist underlayer film has a film thickness of 4 µm or more.

[11]

The pattern forming method according to any one of [1] to [10], wherein the resist composition is a chemically amplified resist composition.

[12]

An ion implantation method in which ions are implanted into the target substrate using the pattern obtained by the pattern forming method according to any one of [1] to [11] as a mask.

[13]

A resist underlayer film, (A) a resin having atoms selected from the group consisting of Si atoms and Ti atoms, and ( B) A laminate in which a resist film formed of a resist composition containing a compound that generates an acid upon irradiation with actinic ray or radiation is laminated in this order.

[14]

A kit comprising: a composition for forming a resist underlayer film for forming the resist underlayer film used in the pattern forming method according to any one of [1] to [11]; and the resist composition.

[15]

The composition for forming a resist underlayer film contained in the kit according to [14].

[16]

A resist composition included in the kit according to [14].

[17]

A composition for forming a resist underlayer film used in the pattern forming method according to any one of [1] to [11].

[18]

A resist composition used in the pattern forming method according to any one of [1] to [11].

[19]

A method for manufacturing an electronic device, comprising the pattern forming method according to any one of [1] to [11] or the ion implantation method according to [12].

According to the present invention, a pattern formation method capable of forming a pattern with a thick film thickness (for example, 2.5 μm or more) and pattern collapse is unlikely to occur, an ion implantation method using the same, and a lamination method used in the pattern formation method A sieve, a kit, a composition for forming a resist underlayer film, a resist composition, and a method for manufacturing an electronic device can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, the preferable aspect of this invention is demonstrated in detail.

In the description of groups and atomic groups in the present specification, when substitution or unsubstitution is not specified, both those having no substituent and those having a substituent shall be included. For example, an "alkyl group" that does not specify substitution or unsubstitution includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

In the present invention, "actinic ray" or "radiation" means, for example, a bright spectrum of a mercury lamp, far ultraviolet ray represented by an excimer laser, extreme ultraviolet ray (EUV light), X-ray, electron beam, particle beam such as an ion beam do. In addition, in this invention, "light" means actinic ray or radiation.

In addition, unless otherwise specified, "exposure" in this specification means not only exposure with deep ultraviolet rays typified by mercury lamps and excimer lasers, X-rays, extreme ultraviolet rays (EUV light), etc., but also particle beams such as electron beams and ion beams. It is assumed that drawing by

In this specification, "(meth)acrylate" means "at least one type of acrylate and methacrylate". In addition, "(meth)acrylic acid" means "at least 1 type of acrylic acid and methacrylic acid".

In this specification, the numerical range indicated using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

In addition, in this invention, "1 angstrom" is synonymous with "0.1 nanometer (nm)".

[Pattern Forming Method]

The pattern forming method of the present invention (hereinafter also referred to as the method of the present invention) comprises:

(1) forming a resist underlayer film on the target substrate;

(2) forming a resist film on the resist underlayer film by using (A) a resist composition containing a resin having an atom selected from the group consisting of Si atoms and Ti atoms;

(3) exposing the resist film;

(4) developing the exposed resist film to form a resist pattern;

(5) using the resist pattern as a mask, and processing the resist underlayer film to form a pattern;

The film thickness of the resist underlayer film is 2.5 µm or more, and the film thickness of the resist film is 1 µm or less.

Since the method of this invention takes such a structure, it is thought that a desired effect is acquired. Although the reason is not clear, it is estimated that it is roughly as follows.

First, the pattern obtained after step (5) of the method of the present invention (hereinafter also referred to as “final pattern”) is formed by processing the resist underlayer film (hereinafter also referred to as “resist underlayer film pattern”) on the pattern formed by processing the resist pattern. This is a prepared pattern.

Here, since the film thickness of the resist underlayer film pattern is 2.5 μm or more, the final pattern including the film thickness of the resist underlayer film pattern also becomes a pattern having a thick film thickness. As described above, the present invention is ultimately intended to form a pattern having a thick film thickness.

And as mentioned above, the film thickness of the resist film for forming a resist pattern is set to 1 micrometer or less. As described above, since the upper limit of the film thickness of the resist film is stipulated, the film thickness of the resist pattern formed by exposure and development is also limited to 1 μm or less. hard to break down

In addition, when the resist underlayer film is processed using the resist pattern as a mask (that is, the resist underlayer film pattern is formed), for example, by adopting a dry treatment such as dry etching treatment, the pattern obtained is formed by a solution such as a developer. You can avoid receiving capillary force. Thereby, the resist underlayer film pattern can also be made hard to collapse|disintegrate.

In addition, the resist pattern obtained from the resist composition in the present invention contains a resin having an atom selected from the group consisting of Si atoms and Ti atoms. Here, since Si atoms and Ti atoms are atoms that impart high etching resistance to the resist pattern, even if etching treatment is performed on the resist underlayer film using the resist pattern having a limited film thickness as described above as a mask, it can be used as a mask. The resist pattern may remain as intended, or it can be processed into a resist underlayer film having a desired shape.

From the above, it is thought that the final pattern becomes a pattern which is hard to collapse|disintegrate, although it has a thick film thickness.

Hereinafter, each process of the pattern formation method of this invention is demonstrated.

[Step (1): Step of forming a resist underlayer film on the target substrate]

The to-be-processed board|substrate in process (1) may be provided on the base layer.

The material of the base layer, the substrate to be processed, and the resist underlayer film is not particularly limited, and each includes, for example, an inorganic substrate such as silicon, SiN, SiO ₂ or SiN, an applied inorganic substrate such as SOG (Spin on Glass), etc. , a substrate generally used in a semiconductor manufacturing process such as an IC, a circuit board manufacturing process such as a liquid crystal or a thermal head, and further other photofabrication lithography processes can be used.

In particular, a silicon (Si) substrate is preferably used as the target substrate.

Further, the substrate to be processed may be a stepped substrate. The step substrate is a substrate in which at least one step shape is formed on the substrate.

When the target substrate is a stepped substrate, the thickness of the resist underlayer film means the height from the bottom surface on the stepped substrate to the top surface of the resist underlayer film to be formed.

For example, in the form of implanting ions into the target substrate, a substrate in which fins and gates are patterned on a flat substrate can be used as the stepped substrate. When a resist underlayer film is applied on a stepped substrate patterned with fins or gates in this way, the film thickness of the resist underlayer film is not the height to the upper surface of the resist underlayer film formed on the upper surface of the fin or gate, but rather on the stepped substrate as described above. It means the height to the top surface of the resist underlayer film formed as the bottom surface.

The size (width, length, height, etc.) of fins and gates, spacing, structure, configuration, etc. are described, for example, in the Journal of Electronics and Information Communication Vol. 91, No. 1, 2008 pages 25-29 "Advanced Fin FET Process and Integration Technology", Jpn. J. Appl. Phys. Vol. 42 (2003) pp. 4142-4146 Part 1, No. 6B, June 2003 "Fin-Type Double-GateMetal-Oxide-Semiconductor Field-Effect Transistors Fabricated by Orientation-Dependent Etching and Electron Beam Lithography" can be appropriately applied.

As the step substrate, for example, the groove width is equal to or less than the exposure wavelength (preferably 100 nm or less, more preferably 40 nm or less, usually 15 nm or more), and the depth is 100 nm or less (preferably 50 to 100 nm, more preferably 65 to A stepped substrate having a groove of 100 nm), a diameter of less than or equal to the exposure wavelength (preferably 100 nm or less, more preferably 40 nm or less, usually 15 nm or more), and a depth of 100 nm or less (preferably 50 to 100 nm, more preferably is 65 to 100 nm), and a stepped substrate having a cylindrical concave portion and the like.

Examples of the stepped substrate having the above-described groove portions include a stepped substrate having a plurality of grooves repeated at equal intervals at a pitch of 20 nm to 200 nm (preferably 50 to 150 nm, more preferably 70 to 120 nm). there is.

Further, as the step substrate having the above-described cylindrical concave portions, a step substrate having a plurality of cylindrical concave portions repeated at equal intervals at a pitch of, for example, 20 nm to 200 nm (preferably 50 to 150 nm, more preferably 70 to 120 nm). and the like.

As the resist underlayer film, a function of improving the pattern resolution of the resist layer and a function of transferring the resist pattern onto the substrate to be processed while maintaining the pattern shape are required, for example, SOC (Spin on Carbon ) layer is suitable.

Moreover, as a resist underlayer film, a crosslinked film is also mentioned suitably. More specifically, a film formed by photocrosslinking or thermal crosslinking of a coating film obtained from a composition containing a resin, a crosslinking agent, a photoacid generator or a thermal acid generator, and optionally added additives is also preferably mentioned. As each component, such as these resin, a crosslinking agent, a thermal acid generator, an additive, a conventionally well-known material can be employ|adopted suitably, for example.

In the present invention, since the film thickness of the resist underlayer film is 2.5 µm or more and the film thickness is thick, "forming the coating film and photocrosslinking or thermal crosslinking of the coating film" is performed multiple times if necessary, and finally formed You may make it so that the film thickness of the resist underlayer film used may be set to 2.5 micrometers or more.

Formation of the to-be-processed substrate and resist underlayer film can be performed by employ|adopting a well-known method suitably according to the kind of material to be used.

In the case of forming the target substrate on the base layer, as the method, a solution containing the material constituting the target substrate is applied onto the base layer by a conventionally known spin coating method, spraying method, roller coating method, immersion method, etc. There may be mentioned a method of applying and drying based on the method, a method of depositing a material constituting the substrate to be processed using a CVD method, and the like.

As a method for forming the resist underlayer film, a liquid containing a material constituting the resist underlayer film is applied on a target substrate based on a conventionally known spin coating method, spray method, roller coating method, dipping method, etc. , a method of depositing a material constituting the resist underlayer film by using the CVD method, and the like. It is preferable that solid content concentration of the liquid containing the material which comprises a resist underlayer film is 10-55 mass %, It is more preferable that it is 15-50 mass %, It is more preferable that it is 20-45 mass %.

The film thickness of the resist underlayer film is 2.5 µm or more, and preferably 4 µm or more. Moreover, it is preferable that it is 30 micrometers or less, as for the film thickness of a resist underlayer film, it is more preferable that it is 25 micrometers or less, It is more preferable that it is 20 micrometers or less.

The resist underlayer film used in the present invention is suitably required to have a function of improving the pattern resolution of the resist film, and a function of transferring the resist pattern formed in the upper layer onto the target substrate while maintaining the pattern shape well. do. One of the functions of assisting the pattern resolution of the resist film is to control the refractive index and extinction coefficient of the resist underlayer film at the exposure wavelength to appropriately control reflection from the substrate side during exposure in the lithography process, and The optical function of maintaining the optical image formed in the favorable shape is mentioned. In addition, as other functions, interaction with the resist is improved by the structure of the main chain and side chains of the resin, and the functional groups of the crosslinking agent or other additives used in combination, thereby maintaining the rectangularity of the pattern cross section after development, and pattern collapse and bridges; The function of assisting the resolution in the developing process after exposure is also mentioned by the effect|action which suppresses development defects, such as a pattern defect. In addition, when the pattern shape is transferred to the target substrate, the resist film formed on the upper layer, the resist underlayer film, and the etching mask when etching is performed under appropriately selected conditions corresponding to the respective thicknesses and etching rates of the target substrate, The function of maintaining good mask performance is also mentioned.

As a method of improving the reflection characteristics during exposure, for example, in the mask exposure process, based on exposure information including the pattern shape and transmittance of the mask, exposure intensity, and the deflection and shape of the projection light source, for example, For example, by simulation software known under the trade name PROLITH (manufactured by KLATencor), the reflection characteristics at the exposure wavelength are improved, and as a result, the refractive index n value and extinction coefficient k value of the underlayer film to maintain rectangularity of the optical image during exposure, and the film of the underlayer film Good reflection characteristics and resolution can be obtained by obtaining target design information such as thickness, and using an appropriate resin structure and additives such as a crosslinking agent for the obtained target. It is preferable that the resist underlayer film of this invention is designed in consideration of the said requested|required property. As a preferable range of the refractive index n value of an underlayer film, it is preferable that they are 1.2 or more and 3.0 or less. Moreover, as a preferable range of the extinction coefficient k value of an underlayer film, it is preferable that it is 0.05 or more and 1.0 or less.

As a method of improving the resolution by maintaining the rectangularity of the pattern cross section and suppressing development defects such as pattern collapse, bridges, and pattern defects, the mechanism is unknown, but the chemical reaction between the resist underlayer film and the resist film is not known. Interaction (intermolecular interaction), footing due to slight interfacial mixing between the resist film and the resist underlayer film, and acid generated during development due to the correlated movement of components between the resist underlayer film and the resist film By changing the reaction activity of the deprotection reaction of the protecting group and the dissolution of the polymer after the reaction into the developing solution, the resolution can be improved as a result. As a resin that can be used for the resist underlayer film, by selecting a more appropriate resin in consideration of the lithography performance and the processability of the substrate to be processed, good resolution and processing aptitude can be obtained.

In addition, as another function, in a lithography process on a processed substrate, it is necessary to form a flat resist underlayer film on a substrate having a concave-convex structure along a pattern shape, and gap-filling properties and application A function to satisfy the flatness of the later is also mentioned.

<Resin for resist underlayer film>

As the resin (hereinafter also referred to as "resin for resist underlayer") that can be used for the resist underlayer film of the present invention, as described above, for example, conventionally known materials can be appropriately employed. However, in the lithography process, It is preferable to arbitrarily design and use the composition using the polymer or resin mentioned later from a viewpoint of making resolution, a defect, and the processability of a to-be-processed board|substrate compatible.

However, the resin for resist underlayer films does not typically have an acid-decomposable group (specifically, the acid-decomposable group in resin (A) mentioned later).

As resin for resist underlayer films, a (meth)acrylic resin, a styrene resin, a cellulose resin, a phenol resin (novolak resin), etc. can be used. In addition, as other resins, aromatic polyester resins, aromatic polyimide resins, polybenzoxazole resins, aromatic polyamide resins, acenaphthylene-based resins, isocyanuric acid-based resins, and the like can be used.

In particular, as the aromatic polyamide resin and the aromatic polyimide resin, for example, the resin compound described in JP-A-4120584, the resin compound described in JP-A-4466877 [0021] to [0053], and JP-A-4525940 The resin compounds described in [0025] to [0050] can be used. Further, as the novolac resin, the resin compounds described in Japanese Patent Publication Nos. 5215825 [0015] to [0058] and Japanese Patent Publication Nos. 5257009 [0023] to [0041] can be used.

Further, as the acenaphthylene-based resin, for example, the resin compound described in Japanese Patent Application Laid-Open No. 4666166 [0032] to [0052], the resin compound described in Japanese Patent Publication No. 04388429 [0037] to [0043], Japanese Patent The polymers described in Publication Nos. 5040839 [0026] to [0065], the resin compounds described in Japanese Patent Publication Nos. 4892670 [0015] to [0032], etc. can be used.

It is also preferable that the resin for resist underlayer film is resin containing the repeating unit containing the hydroxyl group which is a crosslinking reactive group.

Moreover, it is also preferable that resin for resist underlayer films contains the repeating unit which has the lactone structure mentioned later in resin (A).

It is also possible to copolymerize a non-crosslinkable monomer with resin for resist underlayer films, and by this, fine adjustment of dry etching rate, reflectance, etc. can be performed. The following are mentioned as such a copolymerization monomer. For example, an addition polymerizable unsaturated bond selected from acrylic acid esters, acrylamides, methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic acid esters, etc. It is a compound having one

As acrylic acid esters, the C1-C10 alkyl acrylate of an alkyl group is mentioned, for example.

As methacrylic acid esters, the C1-C10 alkyl methacrylate of an alkyl group is mentioned, for example.

Examples of acrylamides include acrylamide, N-alkyl acrylamide, N-aryl acrylamide, N,N-dialkyl acrylamide, N,N-diaryl acrylamide, N-methyl-N-phenyl acrylamide, N -2-acetamide ethyl-N-acetyl acrylamide etc. are mentioned.

Examples of methacrylamides include methacrylamide, N-alkyl methacrylamide, N-aryl methacrylamide, N,N-dialkyl methacrylamide, N,N-diaryl methacrylamide, N-methyl -N-phenylmethacrylamide, N-ethyl-N-phenylmethacrylamide, etc. are mentioned.

As vinyl ethers, alkyl vinyl ether, vinyl aryl ether, etc. are mentioned, for example.

As vinyl esters, vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, etc. are mentioned, for example.

As styrene, styrene, an alkyl styrene, an alkoxy styrene, halogen styrene etc. are mentioned, for example.

Examples of the crotonic acid esters include crotonic acid alkyls such as butyl crotonic acid, hexyl crotonate, and glycerin monocrotonate.

In addition, dialkyl itaconic acid, dialkyl esters or monoalkyl esters of maleic acid or fumaric acid, crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleyl Nitrile etc. are mentioned. In addition, in general, any addition polymerizable unsaturated compound copolymerizable with a polymer containing at least one hydroxyl group as a crosslinking reactive group per repeating unit can be used.

Any of a random polymer, a block polymer, or a graft polymer may be sufficient as resin for resist underlayer films. The polymer forming the resist underlayer film can be synthesized by methods such as radical polymerization, anionic polymerization, and cationic polymerization. Various methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization are possible.

Moreover, various phenolic polymers which have a phenol structure moiety can be used as resin for resist underlayer films. Preferably, a novolak resin, p-hydroxystyrene homopolymer, m-hydroxystyrene homopolymer, a copolymer having a p-hydroxystyrene structure, and a copolymer having a m-hydroxystyrene structure are used. can be heard In these copolymers, it is preferable to have a repeating unit represented by the following general formula (1) as a copolymerization part.

[Formula 1]

In formula, R< ₁ > represents a hydrogen atom, a C1-C3 alkyl group, a cyano group, and a halogen atom, Preferably it is a hydrogen atom or a methyl group. L ₁ represents a single bond, -COO-, -CON(R ₃ )-, an arylene group, and R ₃ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. L ₁ is preferably a single bond, -COO-, or a phenylene group. L ₂ represents a single bond, an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 18 carbon atoms, -COO-, -O-, and preferably a single bond, an alkylene group having 1 to 4 carbon atoms, or a phenylene group. Rb represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 4 to 30 carbon atoms, a bridged alicyclic hydrocarbon group having 5 to 25 carbon atoms, or an aryl group having 6 to 18 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms (methyl group, ethyl group, butyl group, t-butyl group, etc.), a cycloalkyl group having 5 to 8 carbon atoms (cyclohexyl group, cyclooctyl group, etc.), a bridged alicyclic hydrocarbon group having 5 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms ( a phenyl group, a naphthyl group, etc.). These groups may have a substituent, and examples of the substituent include a halogen atom (Cl, Br, etc.), a cyano group, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. An acyl group and a C6-C12 aryl group are mentioned. Preferred skeletons of the bridged alicyclic hydrocarbon group having 5 to 20 carbon atoms are given below.

[Formula 2]

[Formula 3]

Particularly preferred examples of these groups include (5), (6), (7), (8), (9), (10), (13), (14), (15), (23), (28) , (36), (37), (40), (42), (47) are mentioned.

When the resin for resist underlayer film used in the present invention is the copolymer, the content of the repeating unit represented by the general formula (1) is preferably 0 to 80 mol%, more preferably, with respect to all repeating units of the copolymer. is 0 to 60 mol%. Moreover, this copolymer may be a copolymer which has another repeating unit for the purpose of improving film forming property, adhesiveness, developability, etc. in addition to said repeating unit.

The resin for resist underlayer film used for this invention may be a copolymer containing another repeating unit for the purpose of improving film forming property, adhesiveness, developability, etc. other than the repeating unit represented by General formula (1). As a monomer corresponding to such another repeating unit, for example, addition polymerizable selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. The compound which has one unsaturated bond is mentioned.

Specifically, for example, acrylic acid esters, for example, alkyl (the alkyl group preferably has 1 to 10 carbon atoms) acrylate (for example, methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, acrylic acid) Cyclohexyl, ethylhexyl acrylate, octyl acrylate, acrylic acid-t-octyl, chloroethyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, fufuryl acrylate rate, tetrahydrofurfuryl acrylate, etc.);

Methacrylic acid esters, for example, alkyl (the alkyl group preferably has 1 to 10 carbon atoms) methacrylate (for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate) acrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, trimethylol propane monomethacrylate, pentaerythritol monomethacrylate acrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.);

Acrylamides, for example, acrylamide, N-alkyl acrylamide (the alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a heptyl group, an octyl group , cyclohexyl group, hydroxyethyl group, etc.), N,N-dialkylacrylamide (the alkyl group has 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a butyl group, an isobutyl group, an ethylhexyl group , cyclohexyl group, etc.), N-hydroxyethyl-N-methylacrylamide, N-2-acetamide ethyl-N-acetylacrylamide, etc.;

Methacrylamides, for example, methacrylamide, N-alkyl methacrylamide (the alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a t-butyl group, an ethylhexyl group, a hydroxyethyl group, cyclohexyl group, etc.), N,N-dialkylmethacrylamide (the alkyl group includes an ethyl group, a propyl group, a butyl group, etc.), N-hydroxyethyl-N-methylmethacrylamide, etc.;

Allyl compounds, for example, allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.) , allyloxyethanol and the like;

Vinyl ethers, such as alkyl vinyl ethers (eg, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, Chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethyl butyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.);

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barate, vinyl caproate, vinyl chloroacetate, vinyl dichloro acetate, vinyl methoxy acetate, vinyl vu oxyacetate, vinylacetate, vinyllactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate, and the like;

dialkyl itaconic acid (For example, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, etc.); dialkyl esters of fumaric acid (eg, dibutyl fumarate, etc.) or monoalkyl esters; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleironitrile, and the like. In addition, what is necessary is just an addition-polymerizable unsaturated compound copolymerizable with the said various repeating unit.

Suitable examples of the phenolic polymer include the following.

[Formula 4]

[Formula 5]

Resin for resist underlayer films may be used by 1 type, and may be used in 2 or more types.

In one preferred embodiment, the composition for forming a resist underlayer film contains, in addition to the resin, a solvent, an acid generator, a crosslinking agent, a surfactant, and the like. In this case, it is preferable to form a crosslinked film by exposing or heating the coating film formed with the composition for resist underlayer film formation, and to use this as a resist underlayer film.

<Acid generator>

The composition for resist underlayer film formation may contain the acid generator as needed. This acid generator is a component which generate|occur|produces an acid by exposure or heating. By containing an acid generator, the crosslinking reaction in the resist underlayer is inhibited (substances (e.g., bases such as OH-, CH ₃ -, NH ₂ -) generated from a substrate (especially a low dielectric film) resist) By diffusion into the underlayer film, it becomes possible to solve the problem of inactivating the acid in the resist underlayer film and inhibiting the crosslinking reaction). That is, when the acid generator in the formed resist underlayer film reacts with the inhibitory substance, it becomes possible to prevent diffusion of the inhibitory substance into the resist underlayer film.

Among acid generators, as an acid generator that generates an acid upon exposure (hereinafter also referred to as a "photoacid generator"), for example, the compound described in International Publication No. 07/105776 [0076] to [0081]. and the like.

Among these photoacid generators, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium pyrenesulfonate, and diphenyliodonium n-dodecylbenzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium naphthalenesulfonate, bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate, bis( 4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate, bis(4-t-butylphenyl)iodonium n-dodecylbenzenesulfonate, bis(4-t-butylphenyl) Preference is given to iodonium 10-camphorsulfonate, bis(4-t-butylphenyl)iodoniumnaphthalenesulfonate, and bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate. is more preferable. In addition, these photo-acid generators can be used individually or in mixture of 2 or more types.

As a photo-acid generator, the photo-acid generator mentioned later in a resist composition can also be used preferably.

In addition, as an acid generator that generates an acid by heating (hereinafter also referred to as a "thermal acid generator"), for example, 2,4,4,6-tetrabromocyclohexadienone, benzointosylate, 2-nitrobenzyl tosylate, alkyl sulfonates, etc. are mentioned. These thermal acid generators can be used individually or in mixture of 2 or more types. Moreover, as an acid generator, a photo-acid generator and a thermal acid generator can also be used together.

As content rate of an acid generator, 100 mass parts or less are preferable with respect to 100 mass parts of resin for resist underlayer films, 0.1 mass part - 30 mass parts are more preferable, 0.1 mass part - 10 mass parts are especially preferable.

<crosslinking agent>

When the composition for forming a resist underlayer film contains a crosslinking agent, the resist underlayer film is cured at a lower temperature and it becomes possible to form a protective film on the substrate to be processed.

As such a crosslinking agent, various hardening|curing agents other than polynuclear phenols can be used. Examples of the polynuclear phenols include dinuclear phenols such as 4,4'-biphenyldiol, 4,4'-methylenebisphenol, 4,4'-ethylidenebisphenol, and bisphenol A; 4,4',4''-methylidenetrisphenol, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol trinuclear phenols; Polyphenols, such as a novolac, etc. are mentioned. Among these, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and novolak are preferable. In addition, these polynuclear phenols can be used individually or in mixture of 2 or more types.

Moreover, as said hardening|curing agent, diisonato, an epoxy compound, a melamine type hardening|curing agent, a benzoguanamine type hardening|curing agent, a glycoluril type hardening|curing agent, etc. are mentioned, for example. Among these, a melamine type hardening|curing agent and a glycoluril type hardening|curing agent are preferable, and 1,3,4,6- tetrakis (methoxymethyl) glycoluril is more preferable. In addition, these hardening|curing agents can be used individually or in mixture of 2 or more types. Moreover, as a crosslinking agent, polynuclear phenols and a hardening|curing agent can also be used together.

As content rate of a crosslinking agent, 100 mass parts or less are preferable with respect to 100 mass parts of resin for resist underlayer films, 1 mass part - 20 mass parts are more preferable, 1 mass part - 10 mass parts are especially preferable.

<Other optional ingredients>

The composition for resist underlayer film formation may contain other arbitrary components, such as a thermosetting polymer, a radiation absorber, a storage stabilizer, an antifoamer, and an adhesion|attachment adjuvant, as needed other than the said component.

[Step (2): Resist film formation step]

In the step (2), a resist film is formed on the resist underlayer film with a resist composition.

First, the member and material used in the process (2) are demonstrated, and the procedure of the process (2) is demonstrated after that.

[resist composition]

The resist composition of the present invention contains a resin having an atom selected from the group consisting of Si atoms and Ti atoms.

The resist composition of the present invention may be a positive resist composition or a negative resist composition.

The resist composition of the present invention is typically a chemically amplified resist composition.

Hereinafter, each component contained in the resist composition of this invention is demonstrated.

[1] Resin (A)

The resist composition of the present invention contains a resin having an atom selected from the group consisting of Si atoms and Ti atoms.

The resin (A) is preferably a resin having a repeating unit having an atom selected from the group consisting of Si atoms and Ti atoms.

It is preferable that it is resin which has a Si atom, and, as for resin (A), it is more preferable that it is resin which has a repeating unit which has Si atom.

It is preferable that content of Si atoms in resin (A) is 1-30 mass %, It is more preferable that it is 3-25 mass %, It is more preferable that it is 5-20 mass %. However, when the resin (A) has a structure in which a polar group is protected by a leaving group that decomposes and leaves by the action of an acid (that is, has an acid-decomposable group), or the leaving group has a Si atom, the resin (A) ), the amount of Si atoms in the leaving group is not included in the content of Si atoms.

In addition, in this specification, the repeating unit which has both a Si atom and an acid-decomposable group shall correspond to the repeating unit which has Si atom, and also to the repeating unit which has the acid-decomposable group mentioned later. For example, a resin composed of only repeating units having both Si atoms and acid-decomposable groups corresponds to a resin including repeating units having Si atoms and repeating units having acid-decomposable groups.

As described above, when the resin (A) is a resin having an Si atom, the resin (A) is preferably a resin having a repeating unit having an Si atom.

The repeating unit having Si atoms is not particularly limited as long as it has Si atoms. For example, (meth)acrylate having a silane-based repeating unit (-SiR ₂ -: R ₂ is an organic group), a siloxane-based repeating unit (-SiR ₂ -O-: R ₂ is an organic group), and Si atoms and vinyl-based repeating units having Si atoms and the like.

It is preferable that the repeating unit which has Si atom does not have an acid-decomposable group.

It is preferable that the repeating unit which has Si atom has a silsesquioxane structure. Moreover, although you may have a silsesquioxane structure in a principal chain and may have it in a side chain, it is preferable to have in a side chain.

As a silsesquioxane structure, a cage type silsesquioxane structure, a ladder type silsesquioxane structure (ladder type silsesquioxane structure), a random type silsesquioxane structure, etc. are mentioned, for example. Especially, cage-type silsesquioxane structure is preferable.

Here, the cage-type silsesquioxane structure is a silsesquioxane structure which has cage-like frame|skeleton. Although the cage type silsesquioxane structure may be a complete cage type silsesquioxane structure, or an incomplete cage type silsesquioxane structure may be sufficient, it is preferable that it is a complete cage type silsesquioxane structure.

In addition, ladder-type silsesquioxane structure is a silsesquioxane structure which has ladder-like frame|skeleton.

In addition, a random type silsesquioxane structure is a silsesquioxane structure with a random frame|skeleton.

It is preferable that the said cage type silsesquioxane structure is a siloxane structure represented by following formula (S).

[Formula 6]

In the formula (S), R represents a monovalent organic group. A plurality of Rs may be the same or different.

The organic group is not particularly limited, but specific examples include a halogen atom, a hydroxyl group, a nitro group, a carboxy group, an alkoxy group, an amino group, a mercapto group, a blocked mercapto group (for example, a mercap blocked (protected) with an acyl group earthenware), an acyl group, an imide group, a phosphino group, a phosphinyl group, a silyl group, a vinyl group, a hydrocarbon group which may have a hetero atom, a (meth)acryl group-containing group, an epoxy group-containing group, and the like.

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

As a hetero atom of the hydrocarbon group which may have the said hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom etc. are mentioned, for example.

As a hydrocarbon group of the hydrocarbon group which may have the said hetero atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, the group etc. which combined these are mentioned, for example.

The aliphatic hydrocarbon group may be linear, branched or cyclic. Specific examples of the aliphatic hydrocarbon group include a linear or branched alkyl group (especially having 1 to 30 carbon atoms), a linear or branched alkenyl group (particularly having 2 to 30 carbon atoms), a linear or branched alkynyl group (especially , having 2 to 30 carbon atoms) and the like.

As said aromatic hydrocarbon group, C6-C18 aromatic hydrocarbon groups, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group, etc. are mentioned, for example.

It is preferable that the repeating unit which has a Si atom is represented by following formula (I).

[Formula 7]

In the formula (I), L represents a single bond or a divalent linking group.

Examples of the divalent linking group include an alkylene group, -COO-Rt- group, -O-Rt- group, and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.

L is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH ₂ - group, a -(CH ₂ ) ₂ - group, or a -(CH ₂ ) ₃ - group.

In the formula (I), X represents a hydrogen atom or an organic group.

As an organic group, the alkyl group which may have substituents, such as a fluorine atom and a hydroxyl group, is mentioned, for example, A hydrogen atom, a methyl group, a trifluoromethyl group, and a hydroxymethyl group are preferable.

In the formula (I), A represents a Si-containing group. Especially, group represented by a following formula (a) or (b) is preferable.

[Formula 8]

In the formula (a), R represents a monovalent organic group. A plurality of Rs may be the same or different. Specific examples and suitable aspects of R are the same as those of formula (S) described above. In addition, when A in the said Formula (I) is group represented by the said Formula (a), the said Formula (I) is represented by a following formula (I-a).

[Formula 9]

[Formula 10]

In said formula ( _b ), Rb represents the hydrocarbon group which may have a hetero atom. The specific example and suitable aspect of the hydrocarbon group which may have a hetero atom are the same as R in the formula (S) mentioned above.

The number of the repeating unit which has Si atom which resin (A) contains may be 1 type, and may use 2 or more types together.

Although content in particular of the repeating unit which has a Si atom with respect to all repeating units of resin (A) is not restrict|limited, It is preferable that it is 1-70 mol%, and it is more preferable that it is 3-50 mol%.

In a resist composition comprising a resin having a repeating unit having Si atoms, the resin having a repeating unit having Si atoms generates outgas during exposure or elutes into immersion water during immersion exposure, so that the projection lens A component containing Si atoms may adhere to the surface, thereby reducing transmittance. As an aspect for reducing such outgassing and elution, a resin having a repeating unit having a Si atom is stable with respect to an exposure wavelength, or a resin having a repeating unit having a Si atom having a large molecular weight. .

The repeating unit having Si atoms contained in the resin (A) is from a monomer having a turbidity of 1 ppm or less based on JIS K0101: 1998 using formazine as a standard material and using an integrating sphere measurement method as a measurement method. It is preferable that it is the obtained repeating unit. By using a monomer having a turbidity of 1 ppm or less, scum defects are improved.

It is preferable that it is 0.8 ppm or less, and, as for the said turbidity, it is more preferable that it is 0.1 ppm or less. The said turbidity is 0.01 ppm or more normally.

As a method for obtaining the above-mentioned turbidity monomer having Si atoms, for example, a method of purifying a monomer having a silicon atom after synthesis or a commercially available monomer having a turbidity to 1 ppm or less is preferable. As the purification method, a known purification method can be employed, and specific examples thereof include filtration, centrifugation, adsorption, liquid separation, distillation, sublimation, crystallization, and combinations of two or more thereof. there is.

The repeating unit having Si atoms contained in the resin (A) is preferably a repeating unit obtained from a monomer having a purity (GPC purity) defined by a GPC (Gel Permeation Chromatography) area of 95% or more. By using a monomer having a GPC purity of 95% or more, scum defects after pattern formation are improved.

As for GPC purity, it is more preferable that it is 97 % or more, and it is still more preferable that it is 99 % or more. The GPC purity is usually 99.9% or less.

GPC purity can be measured in the test method described below.

GPC Purity measurement method: Measurement is performed by GPC (gel permeation chromatography). For the column, TSKgel SuperHZ 2000 (4.6 mm I.D × 15 cm, manufactured by Tosoh Corporation) and TSKgel SuperHZ 1000 (4.6 mm I.D × 15 cm, manufactured by Tosoh Corporation) were connected, and the eluent was tetrahydrofuran, flow rate 1.0 mL/min, a column temperature of 40°C, a differential refractometer is used for the detector, the sample is a 0.1 wt% tetrahydrofuran solution, and the injection amount is 100 μL. In the obtained chromatogram, when the peaks are separated, vertical division is performed from the minimum value between the peaks, and when the peaks overlap, the vertical division is performed from the inflection point between the peaks, and the area percentage of the main peak is calculated from the area value of each obtained peak do.

When synthesizing a monomer having Si atoms, any known synthesizing method can be employed. For example, the method of Unexamined-Japanese-Patent No. 2008-523220, International Publication No. 01/010871, etc. are mentioned.

The resin solution after polymerization may be purified by a ceramic filter, a nylon filter, or the like.

It is preferable that resin (A) has a repeating unit which has an acid-decomposable group. It is preferable that the repeating unit which has an acid-decomposable group does not have a Si atom.

Here, the acid-decomposable group refers to a group that is decomposed by the action of an acid to generate a polar group.

The acid-decomposable group preferably has a structure protected by a group (leaving group) that decomposes and leaves the polar group by the action of an acid.

As the polar group, phenolic hydroxyl group, carboxyl group, fluorinated alcohol group (preferably hexafluoroisopropanol group), sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkylcarbonyl)imide group, bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris acidic groups (groups which dissociate in 2.38 mass % tetramethylammonium hydroxide aqueous solution), such as (alkylcarbonyl)methylene group and tris(alkylsulfonyl)methylene group, or alcoholic hydroxyl group, etc. are mentioned.

In addition, the alcoholic hydroxyl group is a hydroxyl group bonded to a hydrocarbon group, and refers to a hydroxyl group other than a hydroxyl group directly bonded to an aromatic ring (phenolic hydroxyl group), and the α-position as a hydroxyl group is an aliphatic alcohol substituted with an electron-withdrawing group such as a fluorine atom (e.g. For example, a fluorinated alcohol group (such as a hexafluoroisopropanol group) is excluded. As an alcoholic hydroxyl group, it is preferable that pKa (acid dissociation constant) is a hydroxyl group of 12 or more and 20 or less.

A carboxyl group, a fluorinated alcohol group (preferably hexafluoroisopropanol group), and a sulfonic acid group are mentioned as a preferable polar group.

A group preferable as the acid-decomposable group is a group in which a hydrogen atom of these groups is substituted with a group which leaves an acid.

Examples of the group (leaving group) that leave the acid include -C(R ₃₆ )(R ₃₇ )(R ₃₈ ), -C(R ₃₆ )(R ₃₇ )(OR ₃₉ ), -C(R ₀₁ ) (R ₀₂ )(OR ₃₉ ) and the like.

In the formula, R ₃₆ to R ₃₉ each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.

R ₀₁ and R ₀₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

The alkyl group of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, or an octyl group. and the like.

The cycloalkyl group of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ may be monocyclic or polycyclic. As the monocyclic type, a cycloalkyl group having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable, for example, adamantyl group, norbornyl group, isobornyl group, campanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclodode A real machine, an androstanyl machine, etc. are mentioned. In addition, at least one carbon atom in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

The aryl group of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

The aralkyl group of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

The alkenyl group of R ₃₆ to R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.

The ring formed by bonding R ₃₆ and R ₃₇ is preferably a cycloalkyl group (monocyclic or polycyclic). The cycloalkyl group is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group or an adamantyl group. A monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable, and a monocyclic cycloalkyl group having 5 carbon atoms is particularly preferable.

The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, and a tertiary alkyl ester group. More preferably, it is a tertiary alkyl ester group.

It is preferable that resin (A) has a repeating unit represented by the following general formula (AI) as a repeating unit which has an acid-decomposable group. The repeating unit represented by the general formula (AI) generates a carboxyl group as a polar group by the action of an acid.

[Formula 11]

In the general formula (AI),

Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.

T represents a single bond or a divalent linking group.

Rx ₁ to Rx ₃ each independently represent an alkyl group or a cycloalkyl group.

Two of Rx ₁ to Rx ₃ may combine to form a ring structure.

Examples of the divalent linking group for T include an alkylene group, a -COO-Rt- group, an -O-Rt- group, a phenylene group, and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.

T is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH ₂ - group, a -(CH ₂ ) ₂ - group, or a -(CH ₂ ) ₃ - group. As for T, it is more preferable that it is a single bond.

The alkyl group of X _a1 may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (preferably a fluorine atom).

The alkyl group of X _a1 preferably has 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group or a trifluoromethyl group, but a methyl group is preferable.

It is preferable that X _a1 is a hydrogen atom or a methyl group.

The alkyl group of Rx ₁ , Rx ₂ and Rx ₃ may be linear or branched, and a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, etc. Preferably, it is mentioned. As carbon number of an alkyl group, 1-10 are preferable and 1-5 are more preferable.

Examples of the cycloalkyl group for Rx ₁ , Rx ₂ and Rx ₃ include a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group and an adamantyl group is preferable

Examples of the ring structure formed by combining two of Rx ₁ , Rx ₂ and Rx ₃ include a monocyclic cycloalkane ring such as a cyclopentyl ring and a cyclohexyl ring, a norbornein ring, a tetracyclodecane ring, and a tetracyclododecaine ring. , a polycyclic cycloalkyl group such as an adamantane ring is preferable. A monocyclic cycloalkane ring having 5 or 6 carbon atoms is particularly preferable.

Rx ₁ , Rx ₂ , and Rx ₃ are each independently preferably an alkyl group, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

Said each group may have a substituent, As a substituent, For example, an alkyl group (C1-C4), a cycloalkyl group (C3-C8), a halogen atom, an alkoxy group (C1-C4), a carboxyl group, alkoxy A carbonyl group (C2-6) etc. are mentioned, C8 or less is preferable. Among them, from the viewpoint of further improving the dissolution contrast for a developer containing an organic solvent before and after acid decomposition, it is more preferable that the substituent is a substituent having no heteroatoms such as an oxygen atom, a nitrogen atom, or a sulfur atom (for example, , more preferably not an alkyl group substituted with a hydroxyl group, etc.), a group consisting only of hydrogen atoms and carbon atoms, and particularly preferably a straight-chain or branched alkyl group or cycloalkyl group.

In the general formula (AI), Rx ₁ to Rx ₃ are each independently an alkyl group, and it is preferable that two of Rx ₁ to Rx ₃ are not bonded to form a ring structure. Thereby, an increase in the volume of a group represented by -C(Rx ₁ )(Rx ₂ )(Rx ₃ ) as a group decomposed and desorbed by the action of an acid can be suppressed, and may be carried out after the exposure step and the exposure step The post-exposure heating process WHEREIN: It becomes the tendency which can suppress the volume contraction of an exposure part.

Although the specific example of the repeating unit represented by general formula (AI) is given below, this invention is not limited to these specific examples.

In specific examples, Rx represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rxa and Rxb each independently represent an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms). Xa ₁ represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Z represents a substituent, and when two or more Zs exist, several Z may mutually be same or different. p represents 0 or a positive integer. Specific examples and preferred examples of Z are the same as the specific examples and preferred examples of substituents that each group such as Rx ₁ to Rx ₃ may have.

[Formula 12]

[Formula 13]

[Formula 14]

Moreover, it is also preferable that resin (A) has the repeating unit described in paragraphs [0057] - [0071] of Unexamined-Japanese-Patent No. 2014-202969 as a repeating unit which has an acid-decomposable group.

In addition, the resin (A) may have, as a repeating unit having an acid-decomposable group, a repeating unit generating an alcoholic hydroxyl group described in paragraphs [0072] to [0073] of JP-A-2014-202969 A.

Moreover, it is also preferable that the resin (A) has, as a repeating unit having an acid-decomposable group, a repeating unit having a structure protected by a leaving group in which a phenolic hydroxyl group decomposes and leaves by the action of an acid. In addition, in this specification, a phenolic hydroxyl group is group formed by substituting the hydrogen atom of an aromatic hydrocarbon group with a hydroxyl group. The aromatic ring of the aromatic hydrocarbon group is a monocyclic or polycyclic aromatic ring, and a benzene ring, a naphthalene ring, etc. are mentioned.

The repeating unit represented by the following general formula (AII) is preferable as the repeating unit having a structure protected by a leaving group in which the phenolic hydroxyl group is decomposed and detached by the action of an acid.

[Formula 15]

of general formula (AII),

R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. However, R ₆₂ may combine with Ar ₆ to form a ring, and R ₆₂ in that case represents a single bond or an alkylene group.

X ₆ represents a single bond, -COO-, or -CONR ₆₄ -. R ₆₄ represents a hydrogen atom or an alkyl group.

L ₆ represents a single bond or an alkylene group.

Ar ₆ represents a (n+1) valent aromatic hydrocarbon group, and when combined with R ₆₂ to form a ring, represents a (n+2) valent aromatic hydrocarbon group.

Y ₂ each independently represents a hydrogen atom or a group detached by the action of an acid in the case of n≧2. However, at least one of Y ₂ represents a group which leaves by the action of an acid. It is preferable that the group which leaves|leaves by the action|action _of an acid as Y2 is what was mentioned as said leaving group.

n represents the integer of 1-4.

Each of said groups may have a substituent, As a substituent, For example, an alkyl group (C1-C4), a halogen atom, a hydroxyl group, an alkoxy group (C1-C4), a carboxyl group, and an alkoxycarbonyl group (C2-6 ) etc. are mentioned, and a C8 or less thing is preferable.

[Formula 16]

[Formula 17]

The number of repeating units which have an acid-decomposable group may be one, and may use 2 or more types together.

The content of the repeating unit having an acid-decomposable group contained in the resin (A) (the total when there are a plurality of repeating units having an acid-decomposable group) is 20 to 90 mol% with respect to all the repeating units of the resin (A). It is preferable, and it is more preferable that it is 40-80 mol%. Among them, while the resin (A) has a repeating unit represented by the general formula (AI), the content of the repeating unit represented by the general formula (AI) with respect to all repeating units of the resin (A) is 40 mol% or more it is preferable

The resin (A) preferably has at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure, and has at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure. It is more preferable to have a repeating unit.

As the lactone structure or the sultone structure, any can be used as long as it has a lactone structure or a sultone structure. Preferably, it is a 5-7 membered ring lactone structure or a 5-7 membered ring sultone structure, and has a 5-7 membered ring lactone structure and a bicyclo structure. , it is more preferable that another ring structure is condensed in a form that forms a spiro structure, or that another ring structure is condensed in a form that forms a bicyclo structure or a spiro structure in a 5-7 membered ring sultone structure. It is more preferable to have a repeating unit having a lactone structure represented by any one of the following general formulas (LC1-1) to (LC1-21), or a sultone structure represented by any one of the following general formulas (SL1-1) to (SL1-3). desirable. Moreover, the lactone structure or the sultone structure may couple|bond directly with the principal chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and (LC1-17), and particularly preferred lactone structures. The structure is (LC1-4). By using such a specific lactone structure, LER and image development defect become favorable.

[Formula 18]

The lactone structure moiety or the sultone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxyl group, a halogen atom, a hydroxyl group, and between An ano group, an acid-decomposable group, etc. are mentioned. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n2 represents the integer _of 0-4. When n ₂ is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different. In addition, a plurality of substituents (Rb ₂ ) may be bonded to each other to form a ring.

The repeating unit having a lactone structure or a sultone structure usually has an optical isomer, but any optical isomer may be used. Moreover, 1 type of optical isomer may be used independently, and a some optical isomer may be mixed and used for it. When one type of optical isomer is mainly used, it is preferable that the optical purity (ee) is 90% or more, More preferably, it is 95% or more.

The repeating unit having a lactone structure or a sultone structure is preferably a repeating unit represented by the following general formula (III).

[Formula 19]

In the general formula (III),

A represents an ester bond (group represented by -COO-) or an amide bond (group represented by -CONH-).

When two or more R ₀ is present, each independently represents an alkylene group, a cycloalkylene group, or a combination thereof.

Z is a single bond, an ether bond, an ester bond, an amide bond, a urethane bond, each independently when there is a plurality

[Formula 20]

or urea bonds

[Formula 21]

indicates Here, R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.

R ₈ represents a monovalent organic group having a lactone structure or a sultone structure.

n is the repeating number of the structure represented by -R ₀ -Z-, represents the integer of 0-5, it is preferable that it is 0 or 1, and it is more preferable that it is 0. When n is 0, -R ₀ -Z- does not exist and becomes a single bond.

R ₇ represents a hydrogen atom, a halogen atom, or an alkyl group.

The alkylene group and cycloalkylene group of R ₀ may have a substituent.

Z is preferably an ether bond, an ester bond, particularly preferably an ester bond.

The alkyl group for R ₇ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

The alkylene group, _{cycloalkylene} group, and alkyl group for R ₇ may be substituted, respectively, and examples of the substituent include a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, a mercapto group, a hydroxyl group, Alkoxy groups, such as a methoxy group, an ethoxy group, an isopropoxy group, t-butoxy group, and a benzyloxy group, Acyloxy groups, such as an acetyloxy group and a propionyloxy group, are mentioned.

R ₇ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

The preferable chain alkylene group for R ₀ is preferably chain alkylene having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and examples thereof include a methylene group, ethylene group, and propylene group. . As a preferable cycloalkylene group, it is a C3-C20 cycloalkylene group, For example, a cyclohexylene group, a cyclopentylene group, norbornylene group, an adamantylene group, etc. are mentioned. In order to express the effect of this invention, a chain|strand-chain alkylene group is more preferable, and a methylene group is especially preferable.

The monovalent organic group having a lactone structure or a sultone structure represented by R ₈ is not limited as long as it has a lactone structure or a sultone structure, and specific examples include general formulas (LC1-1) to (LC1-21) and (SL1- The lactone structure or sultone structure represented by any one of 1)-(SL1-3) is mentioned, Among these, the structure represented by (LC1-4) is especially preferable. Moreover, as for n2 in (LC1-1) - (LC1-21), it is more preferable that it is ₂ or less.

Further, R ₈ is preferably an unsubstituted monovalent organic group having a lactone structure or a sultone structure, or a monovalent organic group having a lactone structure or a sultone structure having a methyl group, cyano group or alkoxycarbonyl group as a substituent, cyano A monovalent organic group having a lactone structure (cyanolactone) having a group as a substituent is more preferable.

Specific examples of the repeating unit having a group having a lactone structure or a sultone structure are shown below, but the present invention is not limited thereto.

[Formula 22]

[Formula 23]

[Formula 24]

In order to enhance the effect of the present invention, it is also possible to use together a repeating unit having two or more types of lactone structures or sultone structures.

When the resin (A) contains a repeating unit having a lactone structure or a sultone structure, the content of the repeating unit having a lactone structure or a sultone structure is preferably 5 to 60 mol% based on all the repeating units in the resin (A). and more preferably 5 to 55 mol%, and still more preferably 10 to 50 mol%.

The repeating unit having a carbonate structure (cyclic carbonate structure) is preferably a repeating unit represented by the following general formula (A-1).

[Formula 25]

In general formula (A-1), R _A ¹ represents a hydrogen atom or an alkyl group.

R _A ² , when n is 2 or more, each independently represents a substituent.

A represents a single bond or a divalent linking group.

Z represents an atomic group forming a monocyclic or polycyclic structure together with the group represented by -O-C(=O)-O- in the formula.

n represents an integer of 0 or more.

General formula (A-1) is demonstrated in detail.

The alkyl group represented by R _A ¹ may have a substituent such as a fluorine atom. It is preferable to represent a hydrogen atom, ^a methyl group, or _a trifluoromethyl group, and, as for R A1, it is more preferable to represent a methyl group.

The substituent represented by R _A ² is, for example, an alkyl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, an amino group, or an alkoxycarbonylamino group. Preferably it is a C1-C5 alkyl group, For example, C1-C5 linear alkyl groups, such as a methyl group, an ethyl group, a propyl group, and a butyl group; and branched alkyl groups having 3 to 5 carbon atoms such as isopropyl group, isobutyl group and t-butyl group. The alkyl group may have a substituent, such as a hydroxyl group.

n is an integer greater than or equal to 0 indicating the number of substituents. n is, for example, preferably 0 to 4, more preferably 0.

Examples of the divalent linking group represented by A include an alkylene group, a cycloalkylene group, an ester bond, an amide bond, an ether bond, a urethane bond, a urea bond, or a combination thereof. As an alkylene group, a C1-C10 alkylene group is preferable, A C1-C5 alkylene group is more preferable, For example, a methylene group, an ethylene group, a propylene group, etc. are mentioned.

In one embodiment of the present invention, A is preferably a single bond or an alkylene group.

As a monocyclic ring containing -OC(=O)-O- represented by Z, for example, in the cyclic carbonic acid ester represented by the following general formula (a), a 5-7 membered ring in which n _A =2-4 is mentioned It is preferably a 5-membered ring or a 6-membered ring (n _A =2 or 3), and more preferably a 5-membered ring (n _A =2).

As a polycyclic containing -O-C(=O)-O- represented by Z, for example, a cyclic carbonic acid ester represented by the following general formula (a) forms a condensed ring with one or two or more other ring structures. The structure and the structure which is forming the spiro ring are mentioned. As "another ring structure" capable of forming a condensed ring or a spiro ring, it may be an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring.

[Formula 26]

The monomer corresponding to the repeating unit represented by the said General formula (A-1) is, for example, Tetrahedron Letters, Vol. 27, No. 32p. 3741 (1986), Organic Letters, Vol. 4, No. 15p. 2561 (2002), etc., can be synthesize|combined by the conventionally well-known method.

In resin (A), 1 type in the repeating unit represented by General formula (A-1) may be contained independently, and 2 or more types may be contained.

In the resin (A), the content of the repeating unit having a cyclic carbonate structure (preferably, the repeating unit represented by the general formula (A-1)) is 3 with respect to all the repeating units constituting the resin (A). It is preferable that it is -80 mol%, It is more preferable that it is 3-60 mol%, It is still more preferable that it is 3-45 mol%, It is especially preferable that it is 3-30 mol%, It is most preferable that it is 10-15 mol% desirable. By setting it to such a content rate, developability as a resist, low defect property, low LWR (Line Width Roughness), low PEB (Post Exposure Bake) temperature dependence, a profile, etc. can be improved.

Although the specific example of the repeating unit represented by general formula (A-1) is given below, this invention is not limited to these.

In addition, R A1 in the following specific examples is synonymous with R _A1 in General formula ( _A ^{- 1} ).

[Formula 27]

Resin (A) may have a repeating unit which has a phenolic hydroxyl group.

As a repeating unit which has a phenolic hydroxyl group, a hydroxystyrene repeating unit or a hydroxystyrene (meth)acrylate repeating unit is mentioned. As a repeating unit which has a phenolic hydroxyl group, especially, the repeating unit represented by the following general formula (I) is preferable.

[Formula 28]

during the meal,

R ₄₁ , R ₄₂ and R ₄₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. However, R ₄₂ may combine with Ar ₄ to form a ring, and R ₄₂ in that case represents a single bond or an alkylene group.

X ₄ represents a single bond, -COO-, or -CONR ₆₄ -, and R ₆₄ represents a hydrogen atom or an alkyl group.

L ₄ represents a single bond or a divalent linking group.

Ar ₄ represents a (n+1) valent aromatic hydrocarbon group, and when combined with R ₄₂ to form a ring, represents an (n+2) valent aromatic hydrocarbon group.

n represents the integer of 1-5.

For the purpose of making the repeating unit represented by general formula (I) highly polar, it is also preferable that n is an integer of 2 or more, or X ₄ is -COO- or -CONR ₆₄ -.

Examples of the alkyl group represented by R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, and hexyl group which may have a substituent. , 2-ethylhexyl group, octyl group, and an alkyl group having 20 or less carbon atoms such as a dodecyl group are preferable, an alkyl group having 8 or less carbon atoms is more preferable, and an alkyl group having 3 or less carbon atoms is still more preferable.

The cycloalkyl group represented by R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) may be monocyclic or polycyclic. A monocyclic cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group which may have a substituent, is preferable.

Examples of the halogen atom represented by R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

The alkyl group contained in the alkoxycarbonyl group represented by R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I) is preferably the same as the alkyl group for R ₄₁ , R ₄₂ , and R ₄₃ described above.

Preferred examples of the substituent in each group include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, an urethane group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group, a thioether group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, a nitro group, etc. are mentioned, As for carbon number of a substituent, 8 or less are preferable.

Ar ₄ represents a (n+1) valent aromatic hydrocarbon group. The divalent aromatic hydrocarbon group in the case where n is 1 may have a substituent, for example, an arylene group having 6 to 18 carbon atoms, such as a phenylene group, tolylene group, naphthylene group, and anthracenylene group, or examples For example, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiazole, aromatic hydrocarbon containing heterocyclic rings such as thiazole group is preferred.

As a specific example of the (n+1) valent aromatic hydrocarbon group when n is an integer of 2 or more, (n-1) arbitrary hydrogen atoms are removed from the above-mentioned specific example of a divalent aromatic hydrocarbon group. group can be suitably used.

The (n+1) valent aromatic hydrocarbon group may further have a substituent.

Examples of the substituent that the aforementioned alkyl group, cycloalkyl group, alkoxycarbonyl group and (n+1) valent aromatic hydrocarbon group may have include the alkyl groups represented by R ₄₁ , R ₄₂ , and R ₄₃ in the general formula (I). ; alkoxy groups such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, and a butoxy group; Aryl groups, such as a phenyl group; and the like.

As the alkyl group of R ₆₄ in -CONR ₆₄ - (R ₆₄ represents a hydrogen atom or an alkyl group) represented by X ₄ , a methyl group, an ethyl group, a propyl group, an isopropyl group, or n-view which may have a substituent An alkyl group having 20 or less carbon atoms, such as a tyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, and dodecyl group, is preferable, and an alkyl group having 8 or less carbon atoms is more preferable.

As X ₄ , a single bond, -COO-, or -CONH- is preferable, and a single bond or -COO- is more preferable.

The divalent linking group as L ₄ is preferably an alkylene group, and the alkylene group, which may have a substituent, has 1 to 8 carbon atoms, such as a methylene group, ethylene group, propylene group, butylene group, hexylene group, and octylene group. An alkylene group of

As Ar ₄ , an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent is preferable, and a benzene ring group, a naphthalene ring group, or a biphenylene ring group is more preferable. Especially, it is preferable that the repeating unit represented by general formula (I) is a repeating unit derived from hydroxystyrene. That is, it is preferable that Ar ₄ is a benzene ring group.

Hereinafter, although the specific example of the repeating unit which has a phenolic hydroxyl group is shown, this invention is not limited to this. In formula, a represents 1 or 2.

[Formula 29]

Resin (A) may have the repeating unit which has a phenolic hydroxyl group individually by 1 type, and may have it in combination of 2 or more type.

In the resin (A), the content of the repeating unit having a phenolic hydroxyl group is preferably 40 mol% or more, more preferably 50 mol% or more, and 60 mol% or more, based on all the repeating units in the resin (A). This is more preferable, 85 mol% or less is preferable, and 80 mol% or less is more preferable.

It is preferable that the resin (A) has a repeating unit having a hydroxyl group or a cyano group other than the above-described repeating unit. Thereby, board|substrate adhesiveness and developer affinity improve. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and preferably does not have an acid-decomposable group. As the alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, an adamantyl group, a diamantyl group and a norbornein group are preferable. As a preferable alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, the structure represented by the following general formula is preferable.

[Formula 30]

The content of the repeating unit having a hydroxyl group or a cyano group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 mol%, based on all the repeating units in the resin (A).

Specific examples of the repeating unit having a hydroxyl group or a cyano group include the repeating unit disclosed in Paragraph 0340 of U.S. Patent Application Laid-Open No. 2012/0135348, but the present invention is not limited thereto.

Resin (A) may have a repeating unit which has an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol (for example, a hexafluoroisopropanol group) in which the α-position is substituted with an electron withdrawing group; It is more preferable to have a repeating unit which has a carboxyl group. By containing a repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. Examples of the repeating unit having an alkali-soluble group include a repeating unit in which an alkali-soluble group is directly bonded to the main chain of a resin, such as a repeating unit made of acrylic acid or methacrylic acid, or a repeating unit in which an alkali-soluble group is bonded to the main chain of the resin through a linking group; Furthermore, it is preferable that a polymerization initiator or a chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced into the terminal of the polymer chain, and the linking group may have a monocyclic or polycyclic cyclic hydrocarbon structure. Especially preferably, it is a repeating unit by acrylic acid and methacrylic acid.

As for content of the repeating unit which has an alkali-soluble group, 0-20 mol% is preferable with respect to all the repeating units in resin (A), More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

Specific examples of the repeating unit having an alkali-soluble group include the repeating unit disclosed in Paragraph 0344 of U.S. Patent Application Laid-Open No. 2012/0135348, but the present invention is not limited thereto.

The resin (A) of the present invention further has an alicyclic hydrocarbon structure not having a polar group (eg, the alkali-soluble group, hydroxyl group, cyano group, etc.) . As such a repeating unit, the repeating unit represented by General formula (IV) is mentioned.

[Formula 31]

In the general formula (IV), R ₅ represents a hydrocarbon group having at least one cyclic structure and not having a polar group.

Ra represents a hydrogen atom, an alkyl group, or a -CH ₂ -O-Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group, or an acyl group. A hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group are preferable, and, as for Ra, a hydrogen atom and a methyl group are especially preferable.

The cyclic structure of R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include a cycloalkyl group having 3 to 12 carbon atoms, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group, and a cycloalkenyl group having 3 to 12 carbon atoms, such as a cyclohexenyl group. there is. Preferable monocyclic hydrocarbon group is a C3-C7 monocyclic hydrocarbon group, More preferably, a cyclopentyl group and a cyclohexyl group are mentioned.

The polycyclic hydrocarbon group includes a ring aggregated hydrocarbon group and a crosslinked hydrocarbon group, and examples of the ring aggregated hydrocarbon group include a bicyclohexyl group and perhydronaphthalenyl group. As the cross-linked hydrocarbon ring, for example, pinane, bonein, nopinein, norbornein, bicyclooctane ring (bicyclo[2.2.2]octane ring, bicyclo[3.2.1]octane bicyclic hydrocarbon rings such as ring) and tricyclic hydrocarbon rings such as homobledane, adamantane, tricyclo[5.2.1.0 ^2,6 ]decane and tricyclo[4.3.1.1 ^2,5 ]undecane ring tetracyclic hydrocarbon rings such as a hydrogen ring, a tetracyclo[4.4.0.1 ^{2,5.1 7,10} ]dodecane, and a perhydro-1,4-methano-5,8-methanonaphthalene ring; and the like. there is. In addition, in the cross-linked hydrocarbon ring, a condensed cyclic hydrocarbon ring, for example, perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydro Condensed rings obtained by condensing a plurality of 5- to 8-membered cycloalkane rings such as phenalene rings are also included.

Preferred examples of the cross-linked hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo[5.2.1.0 ^2,6 ]decanyl group, and the like. As a more preferable cross-linked hydrocarbon ring, a norbornyl group and an adamantyl group are mentioned.

These alicyclic hydrocarbon groups may have a substituent, and a halogen atom, an alkyl group, the hydroxyl group by which the hydrogen atom was substituted, the amino group by which the hydrogen atom was substituted, etc. are mentioned as a preferable substituent. As a preferable halogen atom, a bromine, chlorine, and a fluorine atom, and a methyl, ethyl, butyl, and t-butyl group are mentioned as a preferable alkyl group. The above-mentioned alkyl group may further have a substituent, and as a substituent which may further have, a halogen atom, an alkyl group, the hydroxyl group by which the hydrogen atom was substituted, and the amino group by which the hydrogen atom was substituted are mentioned.

Examples of the group in which the hydrogen atom is substituted include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. A preferable alkyl group is an alkyl group having 1 to 4 carbon atoms, a preferable substituted methyl group is methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl group, and a preferable substituted ethyl group is 1- Ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include aliphatic acyl groups having 1 to 6 carbon atoms, such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, and pivaloyl; Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

Resin (A) has an alicyclic hydrocarbon structure having no polar group, and may or may not contain a repeating unit that does not exhibit acid-decomposability. With respect to all the repeating units in it, 1-40 mol% is preferable, More preferably, it is 2-20 mol%.

Specific examples of the repeating unit having an alicyclic hydrocarbon structure not having a polar group and not exhibiting acid-decomposability include the repeating unit disclosed in Paragraph 0354 of U.S. Patent Application Laid-Open No. 2012/0135348, but the present invention is not limited thereto.

The resin (A) used in the method of the present invention, in addition to the above repeating structural units, has the purpose of controlling dry etching resistance, standard developer aptitude, substrate adhesion, resist profile, and general necessary properties of resist such as resolution, heat resistance, sensitivity, etc. may have various repeating structural units. Examples of such a repeating structural unit include, but are not limited to, repeating structural units corresponding to the following monomers.

Thereby, the performance required for the resin (A) used in the method of the present invention, in particular (1) solubility in a coating solvent, (2) film forming property (glass transition point), (3) alkali developability, (4) film Fine adjustment of reducing properties (hydrophobicity, selection of alkali-soluble groups), (5) adhesiveness to the substrate of an unexposed part, (6) dry etching resistance, etc. becomes possible.

As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. and the like.

In addition, as long as it is an addition polymerizable unsaturated compound copolymerizable with the monomer corresponded to the said various repeating structural unit, you may copolymerize.

In the resin (A), the content molar ratio of each repeating structural unit is appropriate to adjust the dry etching resistance of the resist, standard developer aptitude, substrate adhesion, resist profile, and furthermore, the general necessary properties of the resist such as resolution, heat resistance, sensitivity, etc. is set

When the resist composition of the present invention is for ArF exposure, it is preferable that the resin (A) has substantially no aromatic groups from the viewpoint of transparency to ArF light. More specifically, among all the repeating units of the resin (A), it is preferable that the total amount of repeating units having an aromatic group is 5 mol% or less, more preferably 3 mol% or less, and ideally 0 mol%, that is, aromatic groups It is more preferable not to have a repeating unit having Moreover, it is preferable that resin (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure.

Moreover, it is also preferable that resin (A) does not contain a fluorine atom and a silicon atom.

As the resin (A), preferably, all of the repeating units are composed of (meth)acrylate-based repeating units. In this case, all of the repeating units are methacrylate-based repeating units, all of the repeating units are acrylate-based repeating units, and all of the repeating units are methacrylate-based repeating units and acrylate-based repeating units Although any of them can be used, it is preferable that an acrylate-type repeating unit is 50 mol% or less of all repeating units.

Resin (A) can be synthesize|combined according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a batch polymerization method in which a monomer species and an initiator are dissolved in a solvent and heated to perform polymerization, a dropwise polymerization method in which a solution of a monomer species and an initiator is added dropwise to a heating solvent for 1 to 10 hours etc. are mentioned, A dropwise polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, and dimethylformamide , amide solvents such as dimethyl acetamide, and further solvents for dissolving the resist composition of the present invention, such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone, which will be described later. there is. More preferably, polymerization is carried out using the same solvent as the solvent used for the resist composition of the present invention. Thereby, generation of particles during storage can be suppressed.

The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon. As the polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate polymerization. As a radical initiator, an azo-type initiator is preferable, and the azo-type initiator which has an ester group, a cyano group, and a carboxyl group is preferable. As a preferable initiator, azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'- azobis (2-methylpropionate), etc. are mentioned. An initiator is added or divided according to the purpose, and after completion of the reaction, it is poured into a solvent to recover the desired polymer by a method such as powder or solid recovery. Solid content concentration in a reaction solution is 5-50 mass %, Preferably it is 10-30 mass %. Reaction temperature is 10 degreeC - 150 degreeC normally, Preferably it is 30 degreeC - 120 degreeC, More preferably, it is 60-100 degreeC.

In addition, any of a random polymer, a block polymer, and a graft polymer may be sufficient as resin (A).

The weight average molecular weight of resin (A) becomes like this. Preferably it is 1,000-200,000, More preferably, it is 2,000-40,000, More preferably, it is 3,000-30,000, Especially preferably, it is 4,000-25,000. When the weight average molecular weight is 1,000 to 200,000, it is possible to prevent deterioration of heat resistance and dry etching resistance, and it is possible to prevent deterioration of developability or deterioration of film forming properties due to increased viscosity.

The dispersion degree (molecular weight distribution) of resin (A) is 1.0-3.0 normally, Preferably it is 1.0-2.6, More preferably, it is 1.0-2.0, Especially preferably, the thing in the range of 1.1-2.0 is used. The smaller the molecular weight distribution, the better the resolution and the resist shape, the smoother the sidewall of the resist pattern, and the better the roughness.

In addition, in this specification, a weight average molecular weight (Mw) and a dispersion degree are standard polystyrene conversion values calculated|required from the gel permeation chromatography (GPC) of the following conditions.

·Column type: TSK gel Multipore HXL-M (manufactured by Tosoh Corporation, 7.8mm ID × 30.0cm

·Developing solvent: THF (tetrahydrofuran)

·Column temperature: 40°C · Flow rate: 1ml/min

・Sample injection amount: 10 μl

・Device name: HLC-8120 (manufactured by Tosoh Corporation)

The content of the resin (A) is preferably 20 mass % or more, more preferably 40 mass % or more, still more preferably 60 mass % or more, and particularly preferably 80 mass % or more with respect to the total solid content of the resist composition. . It is preferable that content of resin (A) is 99 mass % or less with respect to the total solid of a resist composition.

In this invention, resin (A) may be used by 1 type, and may use two or more together.

[2] Compounds that generate acids by irradiation with actinic rays or radiation

The resist composition of the present invention preferably contains a compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as "photoacid generator"). Although it does not specifically limit as a photo-acid generator, It is preferable that it is a compound which generate|occur|produces an organic acid by irradiation of actinic light or a radiation.

As a photo-acid generator, a photoinitiator of photocationic polymerization, a photoinitiator of photoradical polymerization, a photochromic agent of dyes, a photochromic agent, or a known compound that generates an acid by irradiation with an actinic ray or radiation used for a microresist, and the like; Those mixtures can be appropriately selected and used, for example, compounds described in paragraphs [0039] to [0103] of JP-A-2010-061043, paragraphs [0284] to [0284] of JP-A 2013-004820 0389], but the present invention is not limited thereto.

For example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt, imide sulfonate, oxime sulfonate, diazodisulfone, disulfone, o-nitrobenzyl sulfonate are mentioned.

As the photo-acid generator contained in the resist composition of the present invention, for example, a compound (specific photo-acid generator) that generates an acid upon irradiation with actinic ray or radiation represented by the following general formula (3) is preferably mentioned.

[Formula 32]

(anion)

In general formula (3),

Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.

R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and in the case of two or more R ₄ and R ₅ , each may be the same or different.

L represents a divalent linking group, and L in the case of two or more may be the same or different.

W represents an organic group containing a cyclic structure.

o represents the integer of 1-3. p represents the integer of 0-10. q represents the integer of 0-10.

Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. It is preferable that it is 1-10, and, as for carbon number of this alkyl group, it is more preferable that it is 1-4. Moreover, it is preferable that the alkyl group substituted by at least 1 fluorine atom is a perfluoroalkyl group.

Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Xf is more preferably a fluorine atom or CF ₃ . In particular, it is preferable that both Xf are fluorine atoms.

R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and in the case of two or more R ₄ and R ₅ , each may be the same or different.

The alkyl group as _R4 and R5 _may have a substituent, and a C1-C4 thing is preferable. R ₄ and R ₅ are preferably a hydrogen atom.

Specific examples and suitable aspects of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and suitable aspects of Xf in the general formula (3).

L represents a divalent linking group, and L in the case of two or more may be the same or different.

Examples of the divalent linking group include -COO-(-C(=O)-O-), -OCO-, -CONH-, -NHCO-, -CO-, -O-, -S-, -SO- , -SO ₂ -, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 10 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms) or a combination of a plurality of these A bivalent coupling group, etc. are mentioned. Among these, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -SO ₂ -, -COO-alkylene group-, -OCO-alkylene group-, -CONH-alkyl Rene group- or -NHCO-alkylene group- is preferable, and -COO-, -OCO-, -CONH-, -SO ₂ -, -COO-alkylene group- or -OCO-alkylene group- are more preferable.

W represents an organic group containing a cyclic structure. Especially, it is preferable that it is a cyclic|annular organic group.

Examples of the cyclic organic group include an alicyclic group, an aryl group, and a heterocyclic group.

The alicyclic group may be monocyclic or polycyclic may be sufficient as it. Examples of the monocyclic alicyclic group include a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include polycyclic cycloalkyl groups such as norbornyl group, tricyclodecanyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. Among them, alicyclic groups having a bulky structure having 7 or more carbon atoms, such as norbornyl group, tricyclodecanyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group, diffuse in the film in the PEB (post-exposure heating) process It is preferable from the viewpoint of suppression of performance and improvement of MEEF (Mask Error Enhancement Factor).

The aryl group may be monocyclic or polycyclic may be sufficient as it. Examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group and an anthryl group. Among them, a naphthyl group having a relatively low light absorbance at 193 nm is preferable.

Although the heterocyclic group may be monocyclic or polycyclic may be sufficient as it, polycyclic type can suppress the diffusion of an acid more. Moreover, a heterocyclic group may have aromaticity and does not need to have aromaticity. As a heterocyclic ring which has aromaticity, a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring are mentioned, for example. As a heterocyclic ring which does not have aromaticity, a tetrahydropyran ring, a lactone ring, a sultone ring, and a decahydroisoquinoline ring are mentioned, for example. As a heterocyclic ring in a heterocyclic group, a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring is especially preferable. Moreover, as an example of a lactone ring and a sultone ring, the lactone structure and sultone structure illustrated in the resin mentioned above are mentioned.

The cyclic organic group may have a substituent. As the substituent, for example, an alkyl group (which may be linear or branched, preferably having 1 to 12 carbon atoms), or a cycloalkyl group (any of monocyclic, polycyclic, spiro ring, and preferably having 3 to 20 carbon atoms) ), an aryl group (preferably having 6 to 14 carbon atoms), a hydroxyl group, an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, and a sulfonic acid ester group. Note that the carbon constituting the cyclic organic group (carbon contributing to ring formation) may be carbonyl carbon.

o represents the integer of 1-3. p represents the integer of 0-10. q represents the integer of 0-10.

One aspect WHEREIN: It is preferable that o in General formula (3) is an integer of 1-3, p is an integer of 1-10, and q is 0. It is preferable that Xf is a fluorine atom, it is preferable that both _{R4 and} R5 are hydrogen atoms, and it is preferable that W is a polycyclic hydrocarbon group. It is more preferable that o is 1 or 2, and it is more preferable that it is 1. It is more preferable that p is an integer of 1-3, it is still more preferable that it is 1 or 2, and 1 is especially preferable. W is more preferably a polycyclic cycloalkyl group, and still more preferably an adamantyl group or a diamantyl group.

In the general formula (3), as partial structures other than W, SO ₃ ^- -CF ₂ -CH ₂ -OCO-, SO ₃ ^- -CF ₂ -CHF-CH ₂ -OCO-, SO ₃ ^- -CF ₂ -COO-, SO ₃ ^- -CF ₂ -CF ₂ -CH ₂ -, SO ₃ ^- -CF ₂ -CH(CF ₃ )-OCO- is mentioned as a preferable thing.

(cation)

In general formula (3), X ⁺ represents a cation.

Although X ⁺ is not particularly limited as long as it is a cation, suitable embodiments include, for example, cations (parts other than Z ⁻ ) in general formulas (ZI), (ZII) or (ZIII) described later.

(suitable aspect)

As a suitable aspect of a specific photo-acid generator, the compound represented, for example by the following general formula (ZI), (ZII), or (ZIII) is mentioned.

[Formula 33]

In the general formula (ZI),

R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1 to 20.

Further, two of R ₂₀₁ to R ₂₀₃ may combine to form a ring structure, and an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group may be included in the ring. Examples of the group formed by bonding two of R ₂₀₁ to R ₂₀₃ include an alkylene group (eg, a butylene group and a pentylene group).

Z ⁻ represents the anion in the general formula (3), specifically, the following anion.

[Formula 34]

As the organic group represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ , for example, a corresponding group in the compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described later can be heard

Moreover, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by the general formula (ZI) is a single bond or a linking group with at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by the general formula (ZI) It may be a compound having a structure bonded through it.

As a more preferable component (ZI), the compounds (ZI-1), (ZI-2), and (ZI-3) and (ZI-4) which are demonstrated below are mentioned.

First, compound (ZI-1) will be described.

Compound (ZI-1) is an arylsulfonium compound wherein at least one of R ₂₀₁ to R ₂₀₃ in the general formula (ZI) is an aryl group, that is, a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group, a part of R ₂₀₁ to R ₂₀₃ may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group.

Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, an aryldialkylsulfonium compound, a diarylcycloalkylsulfonium compound, and an aryldicycloalkylsulfonium compound.

As an aryl group of an arylsulfonium compound, a phenyl group and a naphthyl group are preferable, More preferably, it is a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue. When the arylsulfonium compound has two or more aryl groups, two or more aryl groups present may be the same or different.

The alkyl group or cycloalkyl group optionally included in the arylsulfonium compound is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, or n-view. and a tyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group, and cycloalkyl group of R ₂₀₁ to R ₂₀₃ are an alkyl group (eg, 1 to 15 carbon atoms), a cycloalkyl group (eg 3 to 15 carbon atoms), an aryl group (eg, 6 to 14 carbon atoms), You may have an alkoxy group (for example, C1-C15), a halogen atom, a hydroxyl group, and a phenylthio group as a substituent.

Next, compound (ZI-2) is demonstrated.

Compound (ZI-2) is a compound in which R ₂₀₁ to R ₂₀₃ in the formula (ZI) each independently represents an organic group having no aromatic ring. An aromatic ring here also includes the aromatic ring containing a hetero atom.

The organic group not containing an aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R ₂₀₁ to R ₂₀₃ are each independently, preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, an alkoxycarbonylmethyl group, Particularly preferred is a straight-chain or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R ₂₀₃ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group), a cycloalkyl group having 3 to 10 carbon atoms. and an alkyl group (cyclopentyl group, cyclohexyl group, norbornyl group).

R ₂₀₁ to R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, compound (ZI-3) is demonstrated.

A compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound which has a phenacyl sulfonium salt structure.

[Formula 35]

Of the general formula (ZI-3),

R _1c to R _5c are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, Represents a nitro group, an alkylthio group or an arylthio group.

R _6c and R _7c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.

R _x and R _y each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group or a vinyl group.

Any two or more of R _1c to R _5c , R _5c and R _6c , R _6c and R _7c , R _5c and R _x , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure may contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.

Examples of the ring structure include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, or a polycyclic condensed ring in which two or more of these rings are combined. As ring structure, a 3- to 10-membered ring is mentioned, It is preferable that it is a 4-8-membered ring, It is more preferable that it is a 5- or 6-membered ring.

Examples of the group formed by bonding any two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

The group formed by bonding of R _5c and R _6c and R _5c and R _x is preferably a single bond or an alkylene group, and examples of the alkylene group include a methylene group and an ethylene group.

Z _c ⁻ represents an anion in the general formula (3), and is specifically as described above.

Specific examples of the alkoxy group in the alkoxycarbonyl group as R _1c to R _5c are the same as the specific examples of the alkoxy group as R _1c to R _5c .

Specific examples of the alkyl group in the alkylcarbonyloxy group and the alkylthio group as R _1c to R _5c are the same as the specific examples of the alkyl group as R _1c to R _5c above.

Specific examples of the cycloalkyl group in the cycloalkylcarbonyloxy group as R _1c to R _5c are the same as the specific examples of the cycloalkyl group as R _1c to R _5c .

Specific examples of the aryl group in the aryloxy group and arylthio group as R _1c to R _5c are the same as the specific examples of the aryl group as R _1c to R _5c .

Examples of the cation in the compound (ZI-2) or (ZI-3) in the present invention include the cations described in U.S. Patent Application Laid-Open No. 2012/0076996 after paragraph [0036].

Next, compound (ZI-4) is demonstrated.

Compound (ZI-4) is represented by the following general formula (ZI-4).

[Formula 36]

Of the general formula (ZI-4),

R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a cycloalkyl group. These groups may have a substituent.

When two or more R ₁₄ is present, each independently represents a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group. These groups may have a substituent.

R ₁₅ each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have a substituent. Two R ₁₅ may combine with each other to form a ring. When two R ₁₅ are bonded to each other to form a ring, a hetero atom such as an oxygen atom or a nitrogen atom may be included in the ring skeleton. In one embodiment, two R ₁₅ are alkylene groups, and it is preferable to combine with each other to form a ring structure.

l represents the integer of 0-2.

r represents the integer of 0-8.

Z ⁻ represents an anion in the general formula (3), and is specifically as described above.

In the general formula (ZI-4), the alkyl group of R ₁₃ , R ₁₄ and R ₁₅ is linear or branched, preferably having 1 to 10 carbon atoms, methyl group, ethyl group, n-butyl group, t - A butyl group, etc. are preferable.

As a cation of the compound represented by general formula (ZI-4) in this invention, Paragraph [0121] of Unexamined-Japanese-Patent No. 2010-256842, [0123], [0124], and Paragraph of Unexamined-Japanese-Patent No. 2011-076056 and the cations described in [0127], [0129], [0130] and the like.

Next, the general formulas (ZII) and (ZIII) will be described.

In the general formulas (ZII) and (ZIII), R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group, or a cycloalkyl group.

As an aryl group of _R204 - _R207 , a phenyl group and a naphthyl group are preferable, More preferably, it is a phenyl group. The aryl group of R ₂₀₄ to R ₂₀₇ may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocyclic structure include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.

The alkyl group and the cycloalkyl group for R ₂₀₄ to R ₂₀₇ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group), and 3 to 10 carbon atoms. cycloalkyl group (cyclopentyl group, cyclohexyl group, norbornyl group) of

The aryl group, alkyl group, and cycloalkyl group of R ₂₀₄ to R ₂₀₇ may have a substituent. Examples of the substituent that the aryl group, alkyl group, or cycloalkyl group of R ₂₀₄ to R ₂₀₇ may have include an alkyl group (eg, 1 to 15 carbon atoms), a cycloalkyl group (eg 3 to 15 carbon atoms), and an aryl group (eg, Examples thereof include 6 to 15 carbon atoms), an alkoxy group (eg, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

Z ⁻ represents an anion in the general formula (3), and is specifically as described above.

The form of a low molecular compound may be sufficient as a photo-acid generator (a specific photo-acid generator is included. Hereafter, the same), the form contained in a part of a polymer may be sufficient as it. Moreover, you may use together the form contained in the form of a low molecular compound and a part of a polymer.

When the photoacid generator is in the form of a low molecular weight compound, the molecular weight is preferably 580 or more, more preferably 600 or more, still more preferably 620 or more, and particularly preferably 640 or more. Although an upper limit in particular is not restrict|limited, 3000 or less are preferable, 2000 or less are more preferable, and 1000 or less are still more preferable.

When a photo-acid generator is a form contained in a part of a polymer, it may be contained in a part of resin mentioned above, and may be contained in resin other than resin.

A photo-acid generator can be synthesize|combined by a well-known method, For example, it can synthesize|combine according to the method of Unexamined-Japanese-Patent No. 2007-161707.

A photo-acid generator can be used individually by 1 type or in combination of 2 or more types.

The content of the photo-acid generator in the composition (the total when a plurality of types are present) is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, further preferably based on the total solid content of the composition. is 3 to 20 mass%, particularly preferably 3 to 15 mass%.

When the compound represented by the said general formula (ZI-3) or (ZI-4) is included as a photo-acid generator, content of the photo-acid generator contained in a composition (when multiple types exist, the sum total) is a composition Based on the total solid of 25 mass % is especially preferable.

[3] Acid diffusion control agent

The resist composition of the present invention preferably contains an acid diffusion controlling agent. The acid diffusion controlling agent acts as a secondary agent that traps acids generated from a photoacid generator or the like during exposure and suppresses the reaction of the acid-decomposable resin in the unexposed portion by the excess generated acid. As the acid diffusion control agent, a basic compound, a low molecular weight compound having a nitrogen atom and a group that is released by the action of an acid, a basic compound whose basicity is reduced or lost by irradiation with actinic ray or radiation, or relative to a photoacid generator It is possible to use an onium salt that is a weak acid.

As a basic compound, Preferably, the compound which has a structure represented by following formula (A) - (E) is mentioned.

[Formula 37]

In general formulas (A) and (E),

R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and represent a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (6 to 20 carbon atoms) , wherein R ²⁰¹ and R ²⁰² may be bonded to each other to form a ring.

R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and represent an alkyl group having 1 to 20 carbon atoms.

As an alkyl group which has a substituent with respect to the said alkyl group, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.

It is more preferable that the alkyl group in these general formulas (A) and (E) is unsubstituted.

Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine, and the like, and more preferred compounds include imidazole structure, diazabicyclo A compound having a structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and/or an ether linkage, an aniline derivative having a hydroxyl group and/or an ether linkage, etc. can be heard

As a specific example of a preferable compound, the compound illustrated by US2012/0219913A1 is mentioned.

Preferred examples of the basic compound include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.

These basic compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

The resist composition of the present invention may or may not contain a basic compound, but when it contains a basic compound, the content of the basic compound is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid content of the composition. %am.

As for the usage ratio in the composition of a photo-acid generator and a basic compound, photo-acid generator/basic compound (molar ratio) =2.5-300 are preferable, More preferably, it is 5.0-200, More preferably, it is 7.0-150.

It is preferable that the low molecular weight compound (hereinafter also referred to as "compound (C)") which has a nitrogen atom and a group detached by the action of an acid is an amine derivative having a group on the nitrogen atom which is detached by the action of an acid.

As the group that is removed by the action of an acid, an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, and a hemiaminoether group are preferable, and a carbamate group and a hemiaminoether group are particularly preferred. desirable.

100-1000 are preferable, as for the molecular weight of a compound (C), 100-700 are more preferable, and 100-500 are especially preferable.

The compound (C) may have a carbamate group having a protecting group on the nitrogen atom. The protecting group constituting the carbamate group can be represented by the following general formula (d-1).

[Formula 38]

In the general formula (d-1),

Rb is each independently a hydrogen atom, an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 30 carbon atoms), an aryl group (preferably having 3 to 30 carbon atoms), an aralkyl group (preferably having 3 to 30 carbon atoms) represents 1 to 10 carbon atoms) or an alkoxyalkyl group (preferably 1 to 10 carbon atoms). Rb may be linked to each other to form a ring.

The alkyl group, cycloalkyl group, aryl group, aralkyl group represented by Rb is a hydroxyl group, a cyano group, an amino group, a pyrrolidino group, a piperidino group, a morpholino group, a functional group such as an oxo group, an alkoxy group, or a halogen atom It may be substituted. The same applies to the alkoxyalkyl group represented by Rb.

Rb is preferably a linear or branched alkyl group, a cycloalkyl group or an aryl group. More preferably, they are a linear or branched alkyl group and a cycloalkyl group.

Examples of the ring formed by connecting two Rb to each other include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic hydrocarbon group or a derivative thereof.

As a specific structure of the group represented by general formula (d-1), although the structure disclosed by US2012/0135348 A1 [0466] is mentioned, It is not limited to this.

It is especially preferable that the compound (C) has a structure represented by the following general formula (6).

[Formula 39]

In general formula (6), Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. When l is 2, two Ra may be the same or different, and two Ra may be mutually connected and may form a heterocycle with the nitrogen atom in a formula. The heterocycle may contain hetero atoms other than the nitrogen atom in the formula.

Rb is synonymous with Rb in the said General formula (d-1), and a preferable example is also the same.

l represents an integer from 0 to 2, m represents an integer from 1 to 3, satisfying l+m=3.

In the general formula (6), the alkyl group, cycloalkyl group, aryl group, and aralkyl group as Rb are optionally substituted with the alkyl group, cycloalkyl group, aryl group, or aralkyl group as Rb, which may be substituted with the same group as described above. .

Specific examples of the alkyl group, cycloalkyl group, aryl group, and aralkyl group of Ra (these alkyl group, cycloalkyl group, aryl group, and aralkyl group may be substituted with the above group) include the same groups as in the specific examples described above for Rb can be heard

Specific examples of the particularly preferable compound (C) in the present invention include, but are not limited to, compounds disclosed in US2012/0135348A1 [0475].

The compound represented by General formula (6) is compoundable based on Unexamined-Japanese-Patent No. 2007-298569, Unexamined-Japanese-Patent No. 2009-199021, etc.

In the present invention, the low-molecular compound (C) having a group on the nitrogen atom that is detached by the action of an acid can be used alone or as a mixture of two or more.

The content of the compound (C) in the resist composition of the present invention is preferably 0.001 to 20 mass%, more preferably 0.001 to 10 mass%, still more preferably 0.01, based on the total solid content of the composition. -5% by mass.

A basic compound (hereinafter also referred to as "compound (PA)") whose basicity is reduced or lost upon irradiation with actinic ray or radiation has a proton-accepting functional group and is decomposed by irradiation with actinic ray or radiation, It is a compound whose proton-accepting property is reduced, disappears, or changes from proton-accepting property to acidity.

The proton-accepting functional group is a functional group having a group or electrons capable of electrostatic interaction with a proton, for example, a functional group having a macrocyclic structure such as cyclic polyether, or a lone pair of electrons that do not contribute to π-conjugation. It means a functional group having a nitrogen atom with The nitrogen atom which has a lone pair of electrons which does not contribute to (pi) conjugation is a nitrogen atom which has a partial structure shown, for example by a following formula.

[Formula 40]

Preferred partial structures of the proton-accepting functional group include crown ethers, azacrown ethers, primary to tertiary amines, pyridines, imidazoles, and pyrazine structures.

The compound (PA) is decomposed by irradiation with actinic ray or radiation to generate a compound in which the proton-accepting property is lowered, lost, or changed from the proton-accepting property to an acidic one. Here, the decrease or loss of proton-accepting properties, or a change from proton-accepting properties to acidity means changes in proton-accepting properties due to the addition of protons to proton-accepting functional groups, specifically, proton-accepting properties. When a proton adduct is formed from a compound (PA) having a functional group and a proton, it means that the equilibrium constant in the chemical equilibrium decreases.

Proton acceptor properties can be confirmed by measuring pH.

In the present invention, the acid dissociation constant pKa of the compound generated by decomposition of the compound (PA) by irradiation with actinic ray or radiation preferably satisfies pKa<-1, more preferably -13<pKa<- 1, and more preferably -13<pKa<-3.

In the present invention, the acid dissociation constant pKa represents the acid dissociation constant pKa in aqueous solution, for example, as described in Chemical Manual (II) (revised 4th ed., 1993, edited by the Japanese Chemical Society, Maruzen Co., Ltd.), this value It has shown that acid strength is large, so that this is low. The acid dissociation constant pKa in the aqueous solution can be actually measured by measuring the acid dissociation constant at 25°C using an infinitely dilute aqueous solution, and using the following software package 1, Hammett's substituent constant and known The value based on the database of literature values can also be calculated|required by calculation. All of the values of pKa described in this specification represent values obtained by calculation using this software package.

Software Package 1: Advanced Chemistry Development (ACD/Labs) Software V8.14 for Solaris (1994-2007ACD/Labs).

Compound (PA) is the said proton adduct which is decomposed|disassembled and generated upon irradiation with actinic ray or radiation, and generate|occur|produces the compound represented by the following general formula (PA-1), for example. The compound represented by the general formula (PA-1) has an acidic group together with the proton-accepting functional group, so that compared with the compound (PA), the proton-accepting property decreases, disappears, or the compound changed from the proton-accepting property to an acidic one. am.

[Formula 41]

Of the general formula (PA-1),

Q represents -SO ₃ H, -CO ₂ H, or -W ₁ NHW ₂ R _f . Here, R _f represents an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 30 carbon atoms), and W ₁ and W ₂ are , each independently represents -SO ₂ - or -CO-.

A represents a single bond or a divalent linking group.

X represents -SO ₂ - or -CO-.

n represents 0 or 1.

B represents a single bond, an oxygen atom, or -N(R _x )R _y -. Here, R _x represents a hydrogen atom or a monovalent organic group, and R _y represents a single bond or a divalent organic group. R _x may be bonded to R _y to form a ring, or may be bonded to R to form a ring.

R represents a monovalent organic group having a proton-accepting functional group.

The compound (PA) is preferably an ionic compound. Although the proton-accepting functional group may be contained in any of an anion part and a cation part, it is preferable that it is contained in an anion part.

Moreover, in this invention, compounds (PA) other than the compound which generate|occur|produces the compound represented by general formula (PA-1) can also be selected suitably. For example, it is an ionic compound and you may use the compound which has a proton acceptor site|part in the cation part. More specifically, the compound etc. which are represented by the following general formula (7) are mentioned.

[Formula 42]

In the formula, A represents a sulfur atom or an iodine atom.

m represents 1 or 2, and n represents 1 or 2. However, when A is a sulfur atom, m+n=3, when A is an iodine atom, m+n=2.

R represents an aryl group.

R _N represents an aryl group substituted with a proton-accepting functional group. X ⁻ represents a counter anion.

As a specific example of X< ^- >, the thing similar to the anion of the above-mentioned photo-acid generator is mentioned.

Specific examples of the aryl group for R and R _N include preferably a phenyl group.

As a specific example of the proton-accepting functional group which R _N has, it is the same as that of the proton accepting functional group demonstrated by the above-mentioned formula (PA-1).

[0291] Specific examples of the ionic compound having a proton acceptor moiety in the cation moiety below include compounds illustrated in US2011/0269072A1.

In addition, such a compound can be synthesize|combined with reference to the method of Unexamined-Japanese-Patent No. 2007-230913, Unexamined-Japanese-Patent No. 2009-122623, etc., for example.

A compound (PA) may be used individually by 1 type, and may be used in combination of 2 or more type.

0.1-10 mass % is preferable on the basis of the total solid of a composition, and, as for content of a compound (PA), 1-8 mass % is more preferable.

In the resist composition of the present invention, an onium salt, which is a relatively weak acid with respect to the photo-acid generator, can be used as the acid diffusion controlling agent.

When a photo-acid generator and an onium salt that generates an acid, which is a relatively weak acid with respect to the acid generated from the photo-acid generator, are mixed and used, the acid generated from the photo-acid generator by irradiation with actinic light or radiation converts unreacted weak acid anions. When it collides with an onium salt having a strong acid anion, a weak acid is released by salt exchange and an onium salt having a strong acid anion is generated. In this process, since the strong acid is exchanged for a weak acid with a lower catalytic ability, apparently, the acid is deactivated and acid diffusion can be controlled.

It is preferable that it is a compound represented by the following general formula (d1-1) - (d1-3) as an onium salt used as a relatively weak acid with respect to a photo-acid generator.

[Formula 43]

In the formula, R ⁵¹ is a hydrocarbon group which may have a substituent, and Z ^2c is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that the carbon adjacent to S is not substituted with a fluorine atom) ), R ⁵² is an organic group, Y ³ is a linear, branched or cyclic alkylene group or arylene group, Rf is a hydrocarbon group including a fluorine atom, and M ⁺ are each independently, sulfonium or It is an iodonium cation.

Preferred examples of the sulfonium cation or iodonium cation represented by M ⁺ include the sulfonium cations illustrated in the general formula (ZI) and the iodonium cations illustrated in the general formula (ZII).

As a preferable example of the anion part of the compound represented by general formula (d1-1), the structure illustrated in Paragraph [0198] of Unexamined-Japanese-Patent No. 2012-242799 is mentioned.

As a preferable example of the anion part of the compound represented by General formula (d1-2), the structure illustrated by Paragraph [0201] of Unexamined-Japanese-Patent No. 2012-242799 is mentioned.

As a preferable example of the anion part of the compound represented by general formula (d1-3), the structure illustrated by paragraph [0209] and [0210] of Unexamined-Japanese-Patent No. 2012-242799 is mentioned.

The onium salt, which is a relatively weak acid with respect to the photoacid generator, is (C) a compound having a cation moiety and an anion moiety in the same molecule, and the cation moiety and anion moiety are connected by a covalent bond (hereinafter referred to as "compound ( CA)") may be used.

The compound (CA) is preferably a compound represented by any one of the following general formulas (C-1) to (C-3).

[Formula 44]

In general formulas (C-1) to (C-3),

R ₁ , R ₂ , and R ₃ each represent a substituent having 1 or more carbon atoms.

L ₁ represents a divalent linking group or a single bond connecting the cation moiety and the anion moiety.

-X ^- represents an anion moiety selected from -COO ^- , -SO ₃ ^- , -SO ₂ ^- , -N ^- -R ₄ . R ₄ is 1 having a carbonyl group: -C(=O)-, a sulfonyl group: -S(=O) ₂ -, a sulfinyl group: -S(=O)- at the connection site with an adjacent N atom represents a valent substituent.

R ₁ , R ₂ , R ₃ , R ₄ , and L ₁ may be bonded to each other to form a ring structure. Further, in (C-3), two of R ₁ to R ₃ may be combined to form a double bond with the N atom.

Examples of the substituent having 1 or more carbon atoms in R ₁ to R ₃ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, a cycloalkylaminocarbonyl group, and an aryl group. An aminocarbonyl group etc. are mentioned. Preferably, they are an alkyl group, a cycloalkyl group, and an aryl group.

L ₁ as a divalent linking group is a linear or branched alkylene group, a cycloalkylene group, an arylene group, a carbonyl group, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, and a combination of two or more thereof and the like. L ₁ is more preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more thereof.

As a preferable example of the compound represented by general formula (C-1), Paragraph [0037] to [0039] of Unexamined-Japanese-Patent No. 2013-006827, Paragraph [0027] to [0029] of Unexamined-Japanese-Patent No. 2013-008020 compounds can be mentioned.

As a preferable example of the compound represented by General formula (C-2), the compound illustrated by Paragraph [0012] - [0013] of Unexamined-Japanese-Patent No. 2012-189977 is mentioned.

As a preferable example of the compound represented by General formula (C-3), the compound illustrated by Paragraph [0029] - [0031] of Unexamined-Japanese-Patent No. 2012-252124 is mentioned.

The content of the onium salt, which becomes a relatively weak acid with respect to the photoacid generator, is preferably 0.5 to 10.0% by mass, more preferably 0.5 to 8.0% by mass, more preferably 1.0 to 8.0% by mass, based on the solid content of the composition. desirable.

[4] Solvent

The resist composition of the present invention usually contains a solvent.

As a solvent which can be used when preparing a composition, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, lactic acid alkyl ester, alkoxy propionate alkyl, cyclic lactone (preferably C4) to 10), an organic solvent such as a monoketone compound (preferably having 4 to 10 carbon atoms) which may have a ring, alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

Specific examples of these solvents include those described in US Patent Application Laid-Open No. 2008/0187860 [0441] to [0455].

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.

As the hydroxyl group-containing solvent and the hydroxyl group-free solvent, the above-described exemplary compounds can be appropriately selected. As the hydroxyl group-containing solvent, alkylene glycol monoalkyl ether, alkyl lactate, etc. are preferable, and propylene glycol Monomethyl ether (PGME, alias 1-methoxy-2-propanol), ethyl lactate, and methyl 2-hydroxyisobutyrate are more preferable. Moreover, as a solvent which does not contain a hydroxyl group, alkylene glycol monoalkyl ether acetate, alkyl alkoxy propionate, the monoketone compound which may contain a ring, cyclic lactone, alkyl acetate, etc. are preferable, Among these, propylene glycol is preferable. Colmonomethylether acetate (PGMEA, alias 1-methoxy-2-acetoxypropane), ethylethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone and butyl acetate are particularly preferred. and propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, and 2-heptanone are most preferred.

The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40 am. The mixed solvent containing 50 mass % or more of the solvent which does not contain a hydroxyl group is especially preferable at the point of application|coating uniformity.

The solvent preferably contains propylene glycol monomethyl ether acetate, and is a propylene glycol monomethyl ether acetate single solvent or a mixed solvent containing two or more types of propylene glycol monomethyl ether acetate. it is preferable

[5] Surfactant

The resist composition of the present invention may or may not contain a surfactant, and when it contains a fluorine-based and/or silicone-based surfactant (a fluorine-based surfactant, a silicone-based surfactant, and an interface having both fluorine and silicon atoms) active agent), it is more preferable to contain any one or 2 or more types.

When the resist composition of the present invention contains a surfactant, it becomes possible to provide a resist pattern with good sensitivity and resolution, and with few defects in adhesion and development, when an exposure light source of 250 nm or less, particularly 220 nm or less, is used.

As the fluorine-based and/or silicone-based surfactant, the surfactant described in paragraph [0276] of US Patent Application Laid-Open No. 2008/0248425 can be mentioned.

In the present invention, other surfactants other than the fluorine-based and/or silicone-based surfactants described in paragraph [0280] of U.S. Patent Application Laid-Open No. 2008/0248425 may be used.

These surfactants may be used independently and may be used in some combination.

When the resist composition of the present invention contains a surfactant, the amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.0005 to 1% by mass, based on the total solid content of the composition.

[6] Other additives

The resist composition of the present invention may or may not contain an onium carboxylate salt. Examples of such carboxylate onium salts include those described in US Patent Application Laid-Open Nos. 2008/0187860 [0605] to [0606].

These carboxylate onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide, and carboxylic acid with silver oxide in a suitable solvent.

When the resist composition of the present invention contains an onium carboxylate salt, the content thereof is generally 0.1 to 20 mass%, preferably 0.5 to 10 mass%, more preferably 1 to 7 mass%, based on the total solid content of the composition. mass %.

In the resist composition of the present invention, if necessary, an acid-promoting agent, a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, and a compound that promotes solubility in a developer (e.g., molecular weight 1000 The following phenolic compounds, the alicyclic or aliphatic compound which have a carboxyl group) etc. can be contained.

Such phenolic compounds having a molecular weight of 1000 or less are, for example, in Japanese Patent Application Laid-Open No. 4-122938, Japanese Patent Application Laid-Open No. 2-028531, US Patent No. 4,916,210, European Patent Publication No. 219294, etc. Therefore, it can be easily synthesized by those skilled in the art.

Specific examples of the alicyclic or aliphatic compound having a carboxyl group include carboxylic acid derivatives having a steroid structure, such as cholic acid, deoxycholic acid, and lithocholic acid, adamantane carboxylic acid derivative, adamantane dicarboxylic acid, cyclohexanecarboxylic acid, cyclohexane dicarboxylic acid etc. are mentioned, but are not limited to these.

Solid content concentration of the resist composition of this invention is 1.0-20 mass % normally, Preferably it is 2.0-15 mass %, More preferably, it is 2.0-10 mass %. By setting the solid content concentration in the above range, the resist solution can be uniformly applied on the substrate, and furthermore, it becomes possible to form a resist pattern excellent in line width roughness. Although the reason is not clear, it is believed that, as a result, aggregation of the materials in the resist solution, particularly the photo-acid generator, is suppressed, and as a result, a uniform resist film can be formed by setting the solid content concentration to 20% by mass or less. .

The solid content concentration is a weight percentage of the weight of the other resist components excluding the solvent with respect to the total weight of the composition.

The method for preparing the resist composition of the present invention is not particularly limited, but it is preferable to dissolve each component described above in a predetermined organic solvent, preferably the mixed solvent, and filter-filter it. The pore size of the filter used for filter filtration is preferably 0.1 µm or less, more preferably 0.05 µm or less, still more preferably 0.03 µm or less, made of polytetrafluoroethylene, polyethylene, or nylon. In filter filtration, you may perform cyclic filtration like Unexamined-Japanese-Patent No. 2002-062667, or you may perform filtration by connecting multiple types of filters in series or parallel, for example. Moreover, you may filter a composition multiple times. In addition, before and after filter filtration, you may perform a degassing process etc. with respect to a composition.

[Procedure of step (2)]

The procedure of step (2) is not particularly limited, but a method in which a resist composition is applied on a resist underlayer film and, if necessary, a curing treatment is performed (coating method), or a resist film is formed on a supporting body and formed on a substrate The method of transferring a resist film, etc. are mentioned. Among them, the coating method is preferred from the viewpoint of excellent productivity.

[resist film]

For the above reasons, the resist film thickness is 1 µm or less, more preferably 700 nm or less, and still more preferably 500 nm or less.

Moreover, it is preferable that it is 1 nm or more, and, as for the film thickness of a resist film, it is preferable that it is 10 nm or more, It is more preferable that it is 100 nm or more. Such a film thickness can be achieved by setting the solid content concentration in the composition to an appropriate range to have a suitable viscosity, and to improve coating properties and film forming properties.

An adhesion auxiliary layer may be provided between the resist underlayer film and the resist film in order to reduce peeling and collapse of the resist pattern.

As a method of forming the adhesion auxiliary layer, a method of forming an adhesion auxiliary layer having a polymerizable group on the resist underlayer film is preferably exemplified. Since the polymerizable group in the adhesion auxiliary layer formed by this method forms a chemical or physical bond between the resist underlayer film and the resist film, as a result, excellent adhesion between the resist underlayer film and the resist film is expressed. it is thought that

The adhesion auxiliary layer preferably has a polymerizable group. More specifically, it is preferable that the material for forming the adhesion auxiliary layer (especially, preferably resin) has a polymerizable group.

Although the type of polymerizable group is not particularly limited, for example, (meth)acryloyl group, epoxy group, oxetanyl group, maleimide group, itaconic acid ester group, crotonic acid ester group, isocrotonic acid ester group, maleic acid ester group , a styryl group, a vinyl group, an acrylamide group, a methacrylamide group, and the like. Among these, a (meth)acryloyl group, an epoxy group, an oxetanyl group, and a maleimide group are preferable, and a (meth)acryloyl group is more preferable.

The thickness of the adhesion auxiliary layer is not particularly limited, but for the reason that it is possible to form a fine pattern with higher precision, it is preferably 1 to 100 nm, more preferably 1 to 50 nm, more preferably 1 to 10 nm, , it is particularly preferably 1 to 5 nm.

The method of forming the adhesion auxiliary layer is not particularly limited, but a method of forming the adhesion auxiliary layer by applying a composition for forming the adhesion auxiliary layer on the resist underlayer film and, if necessary, performing a curing treatment (application method) Alternatively, a method of forming an adhesion assisting layer on the supporting body and transferring the adhesion assisting layer onto the resist underlayer film, etc. may be mentioned. Among them, the coating method is preferred from the viewpoint of excellent productivity.

The method for applying the composition for forming an adhesion auxiliary layer on the resist underlayer is not particularly limited, and a known method can be used, but spin coating is preferably used in the field of semiconductor manufacturing.

After apply|coating the composition for adhesion auxiliary|assistant layer formation on a resist underlayer film, you may perform a hardening process as needed. Although the hardening process in particular is not restrict|limited, For example, an exposure process, a heat process, etc. are mentioned.

Light irradiation by a UV lamp, visible light, etc. are used for an exposure process. As a light source, there exist a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, etc., for example. Examples of the radiation include electron beams, X-rays, ion beams, and far-infrared rays. As a specific aspect, scanning exposure by an infrared laser, high intensity flash exposure, such as a xenon discharge lamp, infrared lamp exposure, etc. are mentioned suitably.

The exposure time varies depending on the reactivity of the polymer and the light source, but is usually from 10 seconds to 5 hours. As exposure energy, what is necessary is just about 10-10000 mJ/cm< ² >, Preferably it is the range of 100-8000 mJ/cm< ² >.

Moreover, when using heat processing, a blow dryer, oven, an infrared dryer, a heating drum, etc. can be used.

You may combine exposure processing and heat processing.

[Step (3): Exposure Step]

Step (3) is a step of irradiating (exposing) an actinic ray or radiation to the film (resist film) formed in step (2).

As described above, the film thickness of the resist film is set to 1 µm or less, and the film thickness is set to be thin. Accordingly, light during exposure is hardly absorbed by the resin or the like in the resist film, and the light easily reaches the bottom of the exposed portion. As a result, the present invention has an advantage that the exposure sensitivity of the resist film is high.

The light used for exposure is not particularly limited, and examples thereof include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Preferably it is 250 nm or less, More preferably, it is 220 nm or less, More preferably, the far ultraviolet light of the wavelength of 1-200 nm is mentioned.

More specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, EUV (13 nm), electron beam, etc. are mentioned, Among them, KrF excimer laser, ArF It is preferably an excimer laser, EUV or electron beam, more preferably a KrF excimer laser or an ArF excimer laser, and still more preferably a KrF excimer laser.

In the exposure step, an immersion exposure method can be applied. The liquid immersion exposure method can be combined with super-resolution techniques, such as a phase shift method and a modified illumination method. Immersion exposure can be performed according to the method described in Paragraphs [0594] - [0601] of Unexamined-Japanese-Patent No. 2013-242397, for example.

In step (3), it is preferable to expose the resist film by any one of KrF exposure, ArF exposure, and ArF immersion exposure, and it is preferable to expose by KrF exposure.

You may heat-process (PEB:Post Exposure Bake) to the film|membrane which was irradiated (exposed) with actinic ray or radiation in the process (3) before the process (4) mentioned later after a process (3). The reaction of the exposed portion is accelerated by this step. The heat treatment (PEB) may be performed multiple times.

It is preferable that it is 70-130 degreeC, and, as for the temperature of heat processing, it is more preferable that it is 80-120 degreeC.

30-300 second is preferable, as for time of heat processing, 30-180 second is more preferable, It is more preferable that it is 30-90 second.

The heat treatment can be performed by means provided in a normal exposure/developer, or may be performed using a hot plate or the like.

[Step (4): Developing Step]

Step (4) is a step of forming a resist pattern by developing the film irradiated (exposed) with actinic ray or radiation in step (3).

As a preferable embodiment of the resist pattern, a resist pattern having a line portion having a line width of 5000 nm or less is exemplified. In this embodiment, as for the line|wire width of a line part, it is more preferable that it is 1000 nm or less, and it is more preferable that it is 500 nm or less. Moreover, the line width of a line part is 10 nm or more normally.

When a resist pattern having a line portion having a line width in such a range is formed, the cross-sectional shape of the pattern (final pattern) finally obtained after step (5) tends to be a vertically elongated shape (that is, a shape with a large aspect ratio). do. In general, a pattern having a longitudinally long cross-section tends to be easily collapsed, but in the present invention, the resist underlayer pattern is difficult to collapse for the reasons described above. It is very useful in forming a pattern.

The step (4) is preferably a step of forming a resist pattern by developing the exposed resist film with a developer, and the developer may be an alkaline developer or a developer containing an organic solvent.

As an alkali developing solution, although the quaternary ammonium salt represented by tetramethylammonium hydroxide is normally used, besides this, aqueous alkali solutions, such as an inorganic alkali, a primary - tertiary amine, an alcohol amine, and a cyclic amine, can also be used.

Specific examples of the alkali developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; Alkaline aqueous solutions, such as cyclic amines, such as pyrrole and piperidine, can be used. Among these, it is preferable to use the aqueous solution of tetraethylammonium hydroxide.

Moreover, you may add alcohol and surfactant in an appropriate amount to the said alkaline developing solution. The alkali concentration of an alkali developing solution is 0.1-20 mass % normally. The pH of an alkaline developing solution is 10.0-15.0 normally.

The time to develop using an alkali developer is usually 10 to 300 seconds.

The alkali concentration (and pH) and development time of an alkali developing solution can be suitably adjusted according to the pattern to form.

After development using an alkali developer, a rinse solution may be used for washing, or pure water may be used as the rinse solution, and an appropriate amount of a surfactant may be added thereto.

In addition, after the developing treatment or the rinsing treatment, a treatment for removing the developing solution or the rinse solution adhering to the pattern with a supercritical fluid may be performed.

In addition, after the rinse treatment or treatment with the supercritical fluid, heat treatment may be performed to remove moisture remaining in the pattern.

As the organic developer, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents and hydrocarbon solvents can be used. Specifically, for example, Japanese Patent Application Laid-Open No. 2014- In addition to those described in paragraphs [0461] to [0463] of No. 048500, methyl 2-hydroxyisobutyrate, butyl butyrate, isobutyl isobutyrate, butyl propionate, butyl butanate and isoamyl acetate are mentioned.

Two or more said solvents may be mixed, and it may mix with solvents and water other than the above, and may use it. However, in order to fully exhibit the effect of this invention, it is preferable that the moisture content as a whole developing solution is less than 10 mass %, and it is more preferable that it contains substantially no water|moisture content.

That is, it is preferable that the usage-amount of the organic solvent with respect to an organic-type developing solution is 90 mass % or more and 100 mass % or less with respect to the total amount of a developing solution, and it is preferable that it is 95 mass % or more and 100 mass % or less.

In particular, the organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent.

The vapor pressure of the organic developer is preferably 5 kPa or less, more preferably 3 kPa or less, and particularly preferably 2 kPa or less at 20°C. By setting the vapor pressure of the organic developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, the temperature uniformity in the wafer surface is improved, and consequently, the dimensional uniformity in the wafer surface is improved.

An appropriate amount of surfactant can be added to the organic developer as needed.

Although it does not specifically limit as surfactant, For example, an ionic or nonionic fluorine type and/or silicone type surfactant etc. can be used. As these fluorine and/or silicone-based surfactants, for example, Japanese Unexamined Patent Publication No. 62-036663, Japanese Unexamined Patent Publication No. 61-226746, Japanese Unexamined Patent Publication No. 61-226745, and Japanese Unexamined Patent Publication No. 62- 170950, Japanese Unexamined Patent Publication No. 63-034540, Japanese Unexamined Patent Publication No. Hei 7-230165, Japanese Unexamined Patent Publication No. Hei 8-062834, Japanese Unexamined Patent Publication No. Hei 9-054432, Japanese Unexamined Patent Publication No. Hei 9- Surfactants as described in 005988, US Patent No. 5405720, 5360692, 5529881, 5296330, 5436098, 5576143, 5294511, 5824451 are mentioned, Preferably, It is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is more preferable to use a fluorochemical surfactant or silicone type surfactant.

The usage-amount of surfactant is 0.001-5 mass % normally with respect to the total amount of a developing solution, Preferably it is 0.005-2 mass %, More preferably, it is 0.01-0.5 mass %.

The organic developer may contain a basic compound. Specific examples and preferred examples of the basic compound that can be contained in the organic developer used in the present invention are the same as those in the basic compound that the composition can contain as described above as an acid diffusion controlling agent.

As the developing method, for example, a method in which the substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and stopped for a certain period of time (puddle method), and the developer is applied to the surface of the substrate A method of spraying (spray method), a method of continuously discharging a developer while scanning a developer discharge nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method), etc. can be applied. In addition, although it does not specifically limit about the suitable range of the discharge pressure of the discharged developer, the method of adjusting the discharge pressure of a developer, etc., For example, Paragraph [0631] - [0636] of Unexamined-Japanese-Patent No. 2013-242397 are described. Scope and methods are available.

In the pattern formation method of this invention, you may use combining the process of developing using an alkali developing solution (alkali developing process), and the process of developing using the developing solution containing an organic solvent. Thereby, a finer pattern can be formed.

In this invention, although the part with weak exposure intensity|strength is removed by the organic-solvent developing process, the strong part of exposure intensity|strength is also removed by performing an alkali developing process further. In this way, by the multiple development process in which development is performed a plurality of times, pattern formation can be performed without dissolving only the region of intermediate exposure intensity, so that a finer pattern than usual can be formed (paragraph of Japanese Unexamined Patent Publication No. 2008-292975). same mechanism as [0077]).

In the pattern formation method of this invention, although the order of an alkali developing process and an organic-solvent developing process is not specifically limited, It is more preferable to perform alkali development before an organic-solvent developing process.

After the process of developing using the developing solution containing an organic solvent, it is preferable to include the process of washing|cleaning using the rinse aid.

The rinse solution used in the rinse step after the step of developing using a developer containing an organic solvent is not particularly limited as long as the resist pattern is not dissolved, and a solution containing a general organic solvent can be used. As the rinse liquid, it is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent. .

Specific examples of the hydrocarbon-based solvent, the ketone-based solvent, the ester-based solvent, the alcohol-based solvent, the amide-based solvent, and the ether-based solvent include those similar to those described for the developing solution containing the organic solvent.

After the step of developing using a developer containing an organic solvent, more preferably, at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, and hydrocarbon solvents. A step of washing is performed using a rinse solution containing a solvent, more preferably a step of washing using a rinse solution containing an alcohol-based solvent or an ester-based solvent is performed, and particularly preferably, monohydric alcohol is The step of washing is performed using the rinsing solution contained therein, and most preferably, the washing step is performed using a rinsing solution containing a monohydric alcohol having 5 or more carbon atoms.

As the rinse liquid containing a hydrocarbon-based solvent, a hydrocarbon compound having 6 to 30 carbon atoms is preferable, a hydrocarbon compound having 8 to 30 carbon atoms is more preferable, and a hydrocarbon compound having 10 to 30 carbon atoms is particularly preferable. Among them, pattern collapse is suppressed by using a rinse solution containing decane and/or undecane.

When using an ester type solvent as an organic solvent, in addition to an ester type solvent (1 type or 2 types or more), you may use a glycol ether type solvent. As a specific example in this case, using an ester solvent (preferably butyl acetate) as a main component and a glycol ether solvent (preferably propylene glycol monomethyl ether (PGME)) as a secondary component can be heard Thereby, the residual defect is suppressed more.

Here, examples of the monohydric alcohol used in the rinsing step include linear, branched, and cyclic monohydric alcohols, and specifically, 1-butanol, 2-butanol, and 3-methyl-1-view Tanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol and the like can be used. Particularly preferred examples of the monohydric alcohol having 5 or more carbon atoms include 1-hexanol; 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol, and the like can be used.

Two or more of each component may be mixed, and it may mix with organic solvents other than the above, and may use it.

The water content in the rinse liquid is preferably 10 mass % or less, more preferably 5 mass % or less, and particularly preferably 3 mass % or less. When the moisture content is 10% by mass or less, good development characteristics can be obtained.

The vapor pressure of the rinse solution used after the step of developing using a developer containing an organic solvent is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less, and 0.12 kPa or more, 3 kPa or more at 20°C. The following are most preferred. By setting the vapor pressure of the rinse liquid to be 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and swelling due to penetration of the rinse liquid is suppressed, and the dimensional uniformity in the wafer surface is improved.

An appropriate amount of surfactant may be added to the rinse solution and used.

In the rinsing step, a wafer that has been developed using a developing solution containing an organic solvent is cleaned using the rinsing solution containing the organic solvent. Although the method of the cleaning treatment is not particularly limited, for example, a method of continuously discharging a rinse liquid onto a substrate rotating at a constant speed (rotary coating method), a method of immersing the substrate in a bath filled with a rinse liquid for a certain period of time ( dip method), a method of spraying a rinse liquid on the substrate surface (spray method), etc. can be applied. Among them, the cleaning treatment is performed by a spin coating method, and after cleaning, the substrate is rotated at a rotation speed of 2000 rpm to 4000 rpm, and rinsed It is preferred to remove the liquid from the substrate. Moreover, it is also preferable to include a heating process (Post Bake) after a rinse process. The developer and rinse solution remaining between the patterns and inside the patterns are removed by baking. The heating process after the rinse process is 40-160 degreeC normally, Preferably it is 70-95 degreeC, and it is 10 second - 3 minutes normally, Preferably it is 30 second - 90 second.

It is preferable that the resist composition of the present invention and various materials (eg, developer, rinse solution, etc.) used in the pattern forming method of the present invention do not contain impurities such as metals. Examples of the metal impurity component include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, and Li. The total content of impurities contained in these materials is preferably 1 ppm (parts per million) or less, more preferably 10 ppb or less, still more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and 1 ppt or less. is most preferred

As a method of removing impurities, such as a metal, from the said various materials, the filtration using a filter is mentioned, for example. As a filter pore diameter, 50 nm or less of pore size is preferable, 10 nm or less is more preferable, 5 nm or less is still more preferable. As the material of the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. In a filter filtration process, you may connect and use several types of filters in series or parallel. When using multiple types of filters, you may use combining filters from which a pore diameter and/or a material differ. Moreover, various materials may be filtered multiple times, and the process of filtering multiple times may be a circulation filtration process.

In addition, as a method for reducing impurities such as metals contained in the above various materials, methods such as selecting a raw material with a low metal content as a raw material constituting the various materials or performing filter filtration on the raw materials constituting the various materials are mentioned. can Preferred conditions for filter filtration performed on raw materials constituting various materials are the same as those described above.

In addition to filter filtration, impurities may be removed by an adsorbent, or a combination of filter filtration and an adsorbent may be used. As the adsorbent, a known adsorbent can be used, for example, an inorganic adsorbent such as silica gel and zeolite, and an organic adsorbent such as activated carbon can be used.

In order to reduce impurities, such as metal, contained in the said various materials, it is necessary to prevent mixing of the metal impurity in a manufacturing process. Whether or not the metal impurities have been sufficiently removed from the manufacturing apparatus can be confirmed by measuring the content of the metal component contained in the cleaning liquid used for washing the manufacturing apparatus. The content of the metal component contained in the cleaning liquid after use is more preferably 100 ppt (parts per trillion) or less, still more preferably 10 ppt or less, and particularly preferably 1 ppt or less.

The resist composition of the present invention and the organic treatment liquid (resist solvent, developer, rinse liquid, etc.) used in the pattern forming method of the present invention is a chemical solution pipe or various parts ( In order to prevent failure of a filter, O-ring, tube, etc.), a conductive compound may be added. Although it does not restrict|limit especially as an electroconductive compound, For example, methanol is mentioned. Although the amount of addition is not particularly limited, it is preferably 10% by mass or less, and more preferably 5% by mass or less from the viewpoint of maintaining desirable development characteristics. As for the member of the chemical liquid piping, various piping coated with SUS (stainless steel) or antistatic treatment-treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) may be used. can Polyethylene, polypropylene, or a fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) to which an antistatic treatment has been applied can be used similarly for the filter and the O-ring.

With respect to the pattern formed by the method of the present invention, a method for improving the surface roughness of the pattern may be applied. As a method of improving the surface roughness of a pattern, the method of processing a resist pattern by the plasma of hydrogen containing gas disclosed in WO2014/002808A1, for example is mentioned. In addition, Japanese Patent Application Laid-Open No. 2004-235468, US2010/0020297A, Japanese Patent Application Laid-Open No. 2008-083384, Proc. of SPIE Vol. A known method as described in 8328 83280N-1 “Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement” may be applied.

The pattern formation method of the present invention can also be used for guide pattern formation in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol. 4 No. 8 Page 4815-4823).

Moreover, the resist pattern formed by the said method can be used as a core material (core) of the spacer process disclosed in Unexamined-Japanese-Patent No. 3-270227 and Unexamined-Japanese-Patent No. 2013-164509, for example.

Moreover, you may apply a pattern refinement|miniaturization process with respect to the pattern formed by the method of this invention. As a pattern refinement|miniaturization process, as shown, for example in Unexamined-Japanese-Patent No. 2013-145290 and Unexamined-Japanese-Patent No. 2014-071424, the method of apply|coating the composition for refinement|miniaturization on a pattern, and thickening the resist pattern width by heating. can be heard Moreover, in order to maintain the etching resistance of the resist pattern after a refinement|miniaturization process, it is preferable that the composition for refinement|miniaturization contains a silicon atom.

[Step (5): Pattern Forming Step]

Step (5) is a step of forming a pattern by processing the resist underlayer film using the resist pattern formed in step (4) as a mask.

Although the processing method of a resist underlayer film is not specifically limited, It is preferable that the process (5) is a process of forming a pattern by dry-etching with respect to a resist underlayer film using a resist pattern as a mask.

Dry etching may be one-stage etching or etching consisting of multiple stages. In the case where the etching is performed in a plurality of stages, the etching in each stage may be the same process or different processes.

Although the method of the dry etching apparatus is not particularly limited, in particular, plasma such as ICP (Inductive Coupled Plasma) type, 2-frequency CCP (Conductive Coupled Plasma) type, ECR (electron cyclotron resonance) type, etc. A method in which the density and the bias voltage can be independently controlled is more preferable.

All known methods can be used for etching, and various conditions etc. are suitably determined according to the kind, use, etc. of a board|substrate. For example, the International Society of Optical Engineering Kiyo (Proc. of SPIE) Vol. Etching can be performed according to 6924,692420 (2008), Unexamined-Japanese-Patent No. 2009-267112, etc. In addition, the method described in "Chapter 4 Etching" of "Semiconductor Process Manual 4th Edition 2007 Published by: SEMI Japan" can also be followed.

Especially, it is preferable that dry etching with respect to a resist underlayer film is oxygen plasma etching.

Oxygen plasma etching as used herein means plasma etching using a gas containing oxygen atoms, specifically O ₂ , O ₃ , CO, CO ₂ , NO, NO ₂ , N ₂ O, SO, SO ₂ At least one is selected from the group consisting of , COS, and the like. Further, in addition to the oxygen-containing gas, at least one from the group consisting of Ar, He, Xe, Kr, N ₂ , etc. as a diluent gas, Cl ₂ , HBr, BCl ₃ , CH ₄ , NH ₄ etc. At least one may be added from the group consisting of.

When an oxygen atom-containing gas is used, the etching of the resist underlayer film is accelerated by the irradiation effect of oxygen radicals and oxygen ions generated in the plasma. This increases the etching resistance and makes it possible to increase the selectivity between the silicon-containing resist film and the resist underlayer film.

When suppressing pattern dimensional fluctuations before and after etching, an oxygen-containing gas (eg, CO, CO ₂ , NO, NO ₂ , N ₂ O, SO) containing oxygen atoms and at least one of C, N, and S , SO ₂ , COS) by increasing the ratio, the deposition component generated in the plasma adheres to the etching processing pattern sidewall, suppressing the side etching effect by oxygen radicals, and reducing the narrowing of the line width before and after etching it becomes possible The above effect is also achieved by adding CH ₄ or NH ₄ as an additive gas to an oxygen-containing gas (eg O ₂ , O ₃ , CO, CO ₂ , NO, NO ₂ , N ₂ O, SO, SO ₂ , COS). perform the same

In addition, when a gas containing a halogen element other than fluorine, such as Cl ₂ or HBr, is used, high boiling point carbon chloride or carbon bromide is formed as an etching product of the underlayer film, and adhesion to the sidewall of the processing pattern is increased. . Also in this case, the effect of suppressing the side etching by oxygen radicals can be expected.

On the other hand, by appropriately selecting the mixing ratio of the O ₂ or O ₃ gas and the diluent gas, it is possible to control the amount of side etching of the silicon-containing resist film and the resist underlayer film, and perform trimming treatment to a desired dimensional amount at the same time as etching.

In semiconductor device manufacturing, a resist underlayer film or a resist film is coated on a substrate to be processed, followed by exposure and development to form a pattern. In general, the target pattern dimension is actually formed after this pattern formation. There is a process to check that it is done. And for those outside the allowable range of dimensions, the method of peeling/removing an underlayer film or a resist layer, and performing pattern formation from application|coating of the said resist underlayer film or resist film again is generally performed (rework process).

In this case, it is important to completely peel and remove the resist underlayer film and the resist film on the target substrate in order to prevent the occurrence of defects in exposure and development. In a normal resist film peeling method, most of the organic compounds on the substrate are removed by dry treatment (ashing) using oxygen gas, and, if necessary, the resist film can be removed almost completely by performing a rinse treatment, is widely practiced.

However, in a two-layer resist system using a silicon-containing resist film as in the present invention, when the above ashing treatment is performed, the silicon-containing resist film remains in the form of silicon oxide, which may make it difficult to completely remove it.

For this reason, when rework is performed by dry processing, it is necessary to select an etching gas so that the etching rate of the silicon-containing resist film does not become too slow. For example, a fluorine-based gas such as CF ₄ is applicable to this application.

In the case of the dry treatment, as the rework method of the silicon-containing resist film, wet treatment is preferable because there is a possibility that the type of the resist underlayer film used or the substrate to be processed may be limited. Examples of the treatment liquid (removing liquid) applied in this case include, but are not limited to, a mixed liquid of sulfuric acid and hydrogen peroxide solution, an aqueous dilute fluorine solution, an aqueous alkali solution, and an organic solvent.

In the above wet treatment, the addition of a surfactant to the treatment liquid is more preferable for effectively performing wet peeling. As surfactant, a fluorine type surfactant, silicone type surfactant, etc. are mentioned.

Before the wet peeling process, a process such as full surface exposure and heating may be applied to the silicon wafer on which the resist film is formed. By promoting the polarity conversion reaction of the resist film, the effect of improving the solubility in the wet treatment liquid can be expected.

The present invention also relates to an ion implantation method in which ions are implanted into a target substrate using the pattern obtained by the pattern forming method of the present invention as a mask.

As a method of ion implantation, all well-known methods are employable.

The present invention relates to a resist underlayer film, (A) a resin having atoms selected from the group consisting of Si atoms and Ti atoms, and (B) actinic ray on a target substrate used in the pattern forming method of the present invention described above. It also relates to a laminate in which a resist film formed by a resist composition containing a compound that generates an acid upon irradiation with radiation is laminated in this order. In the laminate of the present invention, the details of the substrate to be processed, the resist underlayer film, the resist film, and the like are the same as those described in the pattern forming method of the present invention.

Moreover, this invention relates also to the kit containing the composition for forming a resist underlayer film for forming a resist underlayer film used for the pattern formation method of said this invention, and a resist composition.

Moreover, this invention also relates to the composition for resist underlayer film formation contained in the said kit.

Moreover, this invention also relates to the resist composition contained in the said kit.

Moreover, this invention relates also to the composition for resist underlayer film formation used for the pattern formation method of said this invention.

Moreover, this invention relates also to the resist composition used for the said pattern formation method of this invention.

Moreover, this invention relates also to the manufacturing method of an electronic device containing the pattern formation method or ion implantation method of this invention mentioned above, and the electronic device manufactured by this manufacturing method.

The electronic device of the present invention is suitably mounted on electrical and electronic equipment (home appliances, OA (Office Automation)/media-related equipment, optical equipment, communication equipment, etc.).

Example

Hereinafter, the present invention will be described in more detail by way of Examples, but the present invention is not limited thereto.

<Synthesis Example 1: Synthesis of resin PRP-1>

70.91 g of cyclohexanone was put into a three-necked flask under a nitrogen stream, and this was heated at 80 degreeC. To this, 17.0 g, 10.60 g, 8.17 g of a monomer corresponding to each repeating unit of the resin PRP-1 described below, in order from left, and polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd., 0.553 g) were mixed with 105 g of cyclohexanone. The solution dissolved in the was added dropwise over 6 hours. After completion|finish of dripping, it was further made to react at 80 degreeC for 2 hours. After allowing the reaction solution to cool, it was added dropwise to a methanol/water mixture for 20 minutes, and the precipitated powder was collected by filtration and dried to obtain the following resin PRP-1 (31.6 g), which is an acid-decomposable resin. The composition ratio (molar ratio) of the repeating units determined by the NMR (nuclear magnetic resonance) method was 15/45/40. The weight average molecular weight (Mw) of the obtained resin PRP-1 was 12000 in conversion of standard polystyrene calculated|required from GPC, and the dispersion degree (Mw/Mn) was 1.5.

Other polymers were synthesized in the same order or in the conventional procedure.

The structures of resins PRP-1 to PRP-6 are shown below. In addition, the composition ratio (molar ratio) of each resin, a weight average molecular weight (Mw), and a dispersion degree (Mw/Mn) of each resin are shown below.

[Formula 45]

<Preparation of resin composition>

In the compositions shown in Tables 1 and 2 below, after mixing the raw materials, respectively, the mixture was filtered through a polyethylene filter having a pore size of 0.03 µm to prepare a resist underlayer film forming composition and a resist composition. In addition, in Table 2 below, the Si content (mass %) based on the total amount of resin is shown about each before acid decomposition and after acid decomposition.

[Table 1]

[Table 2]

Each abbreviation in the said table|surface is as follows. In addition, the composition ratio of each repeating unit of resin was shown by molar ratio.

<Resin for resist underlayer film>

[Formula 46]

<crosslinking agent>

[Formula 47]

<Thermal acid generator>

[Formula 48]

<Resin for resist composition>

Resin for resist compositions is as described above.

<Mine generator>

[Formula 49]

<Acid diffusion control agent>

[Formula 50]

<Surfactant>

[Formula 51]

<solvent>

S-1: propylene glycol monomethyl ether acetate (PGMEA)

S-2: propylene glycol monomethyl ether (PGME)

S-3: ethyl lactate

S-4: 3-ethoxypropionate ethyl

[KrF exposure examples] (Examples 1 to 6, Comparative Examples 1 and 2)

A silicon wafer is subjected to HMDS (hexamethyldisilazane) treatment (110° C. for 35 seconds), and a resist underlayer film and a resist film are formed thereon under the conditions shown in Table 3 in this order to form a wafer having a laminate. did. In addition, when there is no description of a layer in a table|surface, formation of the layer was not performed, but the next layer was formed.

The obtained wafer was subjected to pattern exposure using a KrF excimer laser scanner (manufactured by ASML, PAS5500/850) (NA0.80). In addition, as a reticle, the binary mask of the line-and-space pattern with a line width of 200 nm and a space width of 200 nm was used. After that, after baking (Post Exposure Bake; PEB) under the conditions shown in Table 3 below, puddled with the developer shown in Table 3 for 30 seconds to develop, and for examples with a description, puddle with the rinse solution shown in Table 3 below After rinsing, the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds to obtain a line-and-space pattern having a pitch of 400 nm, a line width of 200 nm, and a space width of 200 nm. Table 3 summarizes the results.

[Table 3]

Each abbreviation in the said table|surface is as follows.

<Rinse solution>

D-1: pure

D-2: 4-methyl-2-pentanol

D-3: n-undecane

Next, in Examples 1 to 6 and Comparative Example 2, the resist underlayer film was etched under the following etching conditions using a plasma system parallel plate type reactive ion etching device DES-245R on the silicon wafer on which the resist pattern was formed. did.

(etch condition)

Etching gas: O ₂

Pressure: 20mTorr

Applied power: 800 mW/cm ²

Bias Power: 300W

Evaluation of the said table|surface was performed based on the following evaluation method.

[Pattern collapse]

Patterns described on a silicon wafer as a substrate to be processed (in Examples 1 to 6 and Comparative Examples 2, a laminate of a resist underlayer pattern and a resist pattern, and in Comparative Example 1, a resist pattern) were examined using a length-length scanning electron microscope (SEM ( Note) Observation was performed using Hitachi Seisakusho S-9380II), and pattern collapse was evaluated based on the following criteria.

The pattern collapse area in the wafer area is

A: If less than 5%

B: When it becomes 5% or more and less than 10%

C: When it becomes 10% or more and less than 20%

D: When it becomes 20% or more

As is clear from Table 3, compared with Comparative Example 1 in which the resist underlayer film was not provided and Comparative Example 2 having a large resist layer thickness, according to Examples 1 to 6, while having a thick film thickness (2.5 µm or more) , it was possible to form a pattern excellent in the performance of pattern collapse.

Accordingly, the present invention is very useful, for example, when implanting ions into a substrate in which a specific region is masked by a resist pattern having a thick film thickness, for example, when implanting ions into a deep portion of a substrate.

According to the present invention, a pattern formation method capable of forming a pattern with a thick film thickness (for example, 2.5 μm or more) and pattern collapse is unlikely to occur, an ion implantation method using the same, and a lamination method used in the pattern formation method A sieve, a kit, a composition for forming a resist underlayer film, a resist composition, and a method for manufacturing an electronic device can be provided.

Although this invention was detailed also demonstrated with reference to specific embodiment, it is clear for those skilled in the art that various changes and correction can be added without departing from the mind and range of this invention.

This application is based on the Japanese patent application (Japanese Patent Application No. 2017-165909) of an application on August 30, 2017, The content is taken in here as a reference.

Claims (23)

(1) forming a resist underlayer film on the target substrate;
(2) forming a resist film on the resist underlayer film by using (A) a resist composition containing a resin having Si atoms;
(3) exposing the resist film;
(4) developing the exposed resist film to form a resist pattern;
(5) using the resist pattern as a mask, and processing the resist underlayer film to form a pattern;
The resin (A) contains a repeating unit represented by the following formula (I),
The film thickness of the said resist underlayer film is 2.5 micrometers or more, and the film thickness of the said resist film is 1 micrometer or less, the pattern formation method.

[In the above formula (I),
X represents a hydrogen atom or an organic group,
L represents a single bond or a divalent linking group,
A represents group represented by the following formula (a).]

[In the formula (a), R represents a monovalent organic group. A plurality of Rs may be the same or different.] delete The method according to claim 1,
The content of Si atoms in the said resin (A) is 1-30 mass % on the basis of the total amount of the said resin (A), The pattern formation method. 4. The method according to claim 1 or 3,
The pattern formation method in which the said resin (A) has a repeating unit which has an acid-decomposable group. 4. The method according to claim 1 or 3,
The said resin (A) has at least 1 sort(s) selected from the group which consists of a lactone structure, a sultone structure, and a carbonate structure, The pattern formation method. 4. The method according to claim 1 or 3,
The above step (4) is a step of forming a resist pattern by developing the exposed resist film with a developer, wherein the developing solution is an alkali developer. 4. The method according to claim 1 or 3,
In the step (3), the resist film is exposed by any one of KrF exposure, ArF exposure, and ArF immersion exposure. 4. The method according to claim 1 or 3,
The pattern forming method, wherein the step (5) is a step of forming a pattern by dry etching the resist underlayer film using the resist pattern as a mask. 9. The method of claim 8,
The dry etching with respect to the said resist underlayer film is oxygen plasma etching, the pattern formation method. 4. The method according to claim 1 or 3,
The film thickness of the said resist underlayer film is 4 micrometers or more, the pattern formation method. 4. The method according to claim 1 or 3,
The pattern forming method, wherein the resist composition is a chemically amplified resist composition. An ion implantation method in which ions are implanted into the target substrate using the pattern obtained by the pattern forming method according to claim 1 or 3 as a mask. A compound that generates an acid upon irradiation with a resist underlayer film, (A) a resin having Si atoms, and (B) actinic ray or radiation on a target substrate used in the pattern forming method according to claim 1 or 3 A laminate in which a resist film formed by a resist composition containing
The laminate in which the said resin (A) contains the repeating unit represented by following formula (I).

[In the above formula (I),
X represents a hydrogen atom or an organic group,
L represents a single bond or a divalent linking group,
A represents group represented by the following formula (a).]

[In the formula (a), R represents a monovalent organic group. A plurality of Rs may be the same or different.] A kit comprising the composition for forming a resist underlayer film for forming the resist underlayer film used in the pattern forming method according to claim 1 or 3, and the resist composition according to claim 1 or 3 . A composition for forming a resist underlayer film included in the kit according to claim 14,
A composition for forming a resist underlayer film comprising a resin having a repeating unit represented by the following general formula (1).

[In the above general formula (1),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO-, or a phenylene group,
L ₂ represents a single bond, an alkylene group, or a phenylene group,
Rb represents an alkyl group, a cycloalkyl group, a bridged alicyclic hydrocarbon group, or an aryl group.] A resist composition included in the kit according to claim 14 . A composition for forming a resist underlayer film used in the pattern forming method according to claim 1 or 3,
A composition for forming a resist underlayer film comprising a resin having a repeating unit represented by the following general formula (1).

[In the above general formula (1),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO-, or a phenylene group,
L ₂ represents a single bond, an alkylene group, or a phenylene group,
Rb represents an alkyl group, a cycloalkyl group, a bridged alicyclic hydrocarbon group, or an aryl group.] The resist composition of Claim 1 or 3 used for the pattern formation method of Claim 1 or 3. The manufacturing method of the electronic device including the pattern formation method of Claim 1 or 3. A method of manufacturing an electronic device comprising the ion implantation method according to claim 12 . 4. The method according to claim 1 or 3,
The pattern formation method in which the said resin (A) contains the repeating unit represented by the following general formula (AI).

[In the above general formula (AI),
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom,
T represents a single bond or a divalent linking group,
Rx ₁ to Rx ₃ each independently represent an alkyl group or a cycloalkyl group, and two of Rx ₁ to Rx ₃ may combine to form a ring structure.] 4. The method according to claim 1 or 3,
The pattern formation method in which the said resin (A) has at least 1 sort(s) selected from the group which consists of a lactone structure and a sultone structure. 4. The method according to claim 1 or 3,
The resist underlayer film is formed of a composition containing a resin having a repeating unit represented by the following general formula (1).

[In the above general formula (1),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO-, or a phenylene group,
L ₂ represents a single bond, an alkylene group, or a phenylene group,
Rb represents an alkyl group, a cycloalkyl group, a bridged alicyclic hydrocarbon group, or an aryl group.]