WO2016163174A1

WO2016163174A1 - Pattern forming method, etching method and method for manufacturing electronic device

Info

Publication number: WO2016163174A1
Application number: PCT/JP2016/056082
Authority: WO
Inventors: 錦藤巻; 三千紘白川; 杉山　真一; 慶山本; 直也井口
Original assignee: 富士フイルム株式会社
Priority date: 2015-04-07
Filing date: 2016-02-29
Publication date: 2016-10-13
Also published as: TW201636735A; JPWO2016163174A1

Abstract

Provided are: a pattern forming method which is capable of forming a multistage resist pattern that is reduced in defects; an etching method which uses this pattern forming method; and a method for manufacturing an electronic device, which uses this pattern forming method. This pattern forming method comprises: a step for forming a first film on a substrate using an active light sensitive or radiation sensitive resin composition (1); a step for exposing the first film to light; a step for forming a first pattern by developing the light-exposed first film with use of a developer liquid; a step for forming a second film at least on the first pattern using an active light sensitive or radiation sensitive resin composition (2); a step for exposing the second film to light; and a step for forming a second pattern at least on the first pattern by developing the light-exposed second film with use of a developer liquid. At least one of the active light sensitive or radiation sensitive resin compositions (1), (2) contains a resin that comprises a repeating unit having an Si atom.

Description

PATTERN FORMING METHOD, ETCHING METHOD, AND ELECTRONIC DEVICE MANUFACTURING METHOD

The present invention relates to a pattern forming method, an etching method using the same, and a method for manufacturing an electronic device including the same. More specifically, the present invention relates to a pattern forming method suitable for a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, a manufacturing process such as a MEMS, and a photolithographic lithography process. The present invention also relates to an etching method using the same. In particular, the present invention relates to a pattern forming method suitable for exposure in KrF, ArF exposure apparatus and ArF immersion projection exposure apparatus using far ultraviolet light having a wavelength of 300 nm or less as a light source, and an etching method using the same. And a method of manufacturing an electronic device including the same.

In recent years, with the demand for diversification and higher functionality of electronic devices, it has been required to form fine patterns of various shapes by etching or the like. For example, disclosed in FIGS. 1 to 7 of Patent Document 1 As is known, a method of forming a multi-stage structure in a photoresist layer is known.

JP 2007-173826 A

An object of the present invention is to provide a pattern forming method capable of forming a multistage resist pattern (for example, a pattern in which a line pattern is laminated on a hole pattern) with reduced defects, and an etching method using the same. To do.

The present invention has the following configuration, which solves the above-described problems of the present invention.

[1] (i) A step of forming the first pattern on the substrate by performing the following step (i-1), the following step (i-2) and the following step (i-3) in this order;
(I-1) a step of forming a first film on the substrate using the actinic ray-sensitive or radiation-sensitive resin composition (1) (i-2) a step of exposing the first film i-3) Step of developing the exposed first film using a developer to form the first pattern (iii) Actinic ray sensitive or radiation sensitive at least on the first pattern Forming a second film using the resin composition (2);
(V) exposing the second film; and
(Vi) developing the exposed second film using a developer to form a second pattern on at least the first pattern;
A pattern forming method comprising:
A pattern in which at least one of the actinic ray-sensitive or radiation-sensitive resin compositions (1) and (2) is an actinic ray-sensitive or radiation-sensitive resin composition containing a resin containing a repeating unit having a Si atom. Forming method.
[2] The content of the resin including the repeating unit having the Si atom is 10% by mass or more based on the total solid content in the actinic ray-sensitive or radiation-sensitive resin composition. Pattern formation method.
[3] The pattern forming method according to [1] or [2], wherein the content of Si atoms in the resin containing repeating units having Si atoms is 1.0 to 30% by mass.
[4] The pattern forming method according to any one of [1] to [3], wherein the resin containing a repeating unit having an Si atom has an acid-decomposable group.
[5] The pattern forming method according to any one of [1] to [4], wherein the repeating unit having an Si atom has a silsesquioxane structure.
[6] The pattern forming method according to [5], wherein the silsesquioxane structure is a cage-type silsesquioxane structure.
[7] The pattern forming method according to any one of [1] to [6], wherein the resin includes a repeating unit having at least one of a lactone structure, a sultone structure, and a carbonate structure.
[8] The pattern forming method according to any one of [1] to [7], wherein the developer used in the step (i-3) is a developer containing an organic solvent.
[9] The pattern forming method according to any one of [1] to [8], wherein the developer used in the step (vi) is a developer containing an organic solvent.
[10] The actinic ray-sensitive or radiation-sensitive resin composition (1) contains a resin that increases in polarity by the action of an acid and decreases in solubility in a developer containing an organic solvent. [9] The pattern forming method according to any one of [9].
[11] The actinic ray-sensitive or radiation-sensitive resin composition (2) contains a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases, [10] The pattern forming method according to any one of [10].
[12] The pattern forming method according to any one of [1] to [11], further including a heating step (ii) between the step (i) and the step (iii).
[13] The pattern forming method according to any one of [1] to [12], further including a heating step after the step (vi).
[14] The pattern forming method according to any one of [1] to [13], wherein the actinic ray-sensitive or radiation-sensitive resin composition (2) contains a resin containing a repeating unit having an Si atom.
[15] The pattern forming method according to any one of [1] to [14], wherein the actinic ray-sensitive or radiation-sensitive resin composition (1) contains a resin containing a repeating unit having a Si atom.
[16] Any one of [1] to [15], wherein the actinic ray sensitive or radiation sensitive resin composition (1) is different from the actinic ray sensitive or radiation sensitive resin composition (2). The pattern forming method according to 1.
[17] Any one of [1] to [15], wherein the actinic ray sensitive or radiation sensitive resin composition (1) and the actinic ray sensitive or radiation sensitive resin composition (2) are the same. The pattern forming method according to 1.
[18] An etching method in which an etching process is performed on the substrate using the pattern formed by the pattern forming method according to any one of [1] to [17] as a mask.
[19] A method for manufacturing an electronic device, comprising the pattern forming method according to any one of [1] to [18].

According to the present invention, it is possible to provide a pattern forming method capable of forming a multistage resist pattern with reduced defects and an etching method using the same.

1A to 1E are schematic perspective views for explaining a pattern forming method and an etching method according to an embodiment of the present invention, respectively. 2A to 2E are schematic cross-sectional views for explaining a pattern forming method and an etching method according to an embodiment of the present invention, respectively.

Hereinafter, embodiments of the present invention will be described in detail.
In the description of the group (atomic group) in this specification, the notation which does not describe substitution and non-substitution includes the thing which has a substituent with the thing which does not have a substituent. For example, the “alkyl group” 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 specification, “active light” or “radiation” means, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer laser, extreme ultraviolet rays (EUV light), X-rays, electron beams (EB), etc. To do. In the present invention, light means actinic rays or radiation.
In addition, “exposure” in the present specification is not limited to exposure with a bright line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays, X-rays, EUV light, etc. Drawing with particle beams such as ion beams is also included in the exposure.

<Pattern formation method and etching method>
Below, the pattern formation method of this invention and the etching method using the same are demonstrated.
First, the pattern forming method of the present invention includes:
(I) a step of forming the first pattern on the substrate by performing the following step (i-1), the following step (i-2) and the following step (i-3) in this order;
(I-1) Step of forming a first film on the substrate by using the actinic ray-sensitive or radiation-sensitive resin composition (1) (i-2) Step of exposing the first film (i- 3) Step of developing the exposed first film using a developer to form a first pattern (iii) Actinic ray-sensitive or radiation-sensitive resin composition (2) on at least the first pattern ) To form the second film using
(V) exposing the second film; and
(Vi) a step of developing the exposed second film using a developer to form a second pattern on at least the first pattern;
In this order, at least one of the actinic ray-sensitive or radiation-sensitive resin compositions (1) and (2) contains a resin containing a repeating unit having Si atoms.

The reason why the multistage resist pattern with reduced defects can be easily formed by the pattern forming method of the present invention is estimated as follows.

First, the pattern forming method of the present invention includes at least patterning by step (i) (steps (i-1) to (i-3)) and patterning by steps (iii), (v) and (vi). Contains two times of patterning.
Here, the second pattern formed by the steps (iii), (v) and (vi) is obtained from the second film formed on the first pattern formed by the step (i). Therefore, the size and shape of the first pattern and the size and shape of the second pattern can be designed independently of each other.
Therefore, for example, a pattern having a multistage structure in which a line pattern (second pattern) is stacked on a hole pattern (first pattern) can be formed.

Moreover, in the pattern formation method of this invention, at least one of actinic-ray-sensitive or radiation-sensitive resin composition (1), (2) contains resin containing the repeating unit which has Si atom.
Since the resin containing a repeating unit having Si atoms has high solubility in a developing solution, generation of defects is suppressed.

In the pattern formation method of the present invention, each of the step (i), the step (iii), the step (v) and the step (vi) can be performed by a generally known method.

FIGS. 1A to 1E are schematic perspective views for explaining a pattern forming method and an etching method according to an embodiment of the present invention, respectively. 2A to 2E are schematic cross-sectional views for explaining a pattern forming method and an etching method according to an embodiment of the present invention, respectively.

<Step (i): Formation of first pattern>
In this embodiment, first, as shown in FIGS. 1 (a) and 2 (a), the following step (i-1), the following step (i-2), and the following step (i-) are performed on the substrate 10. 3) are performed in this order, and, for example, the first pattern 51 having a plurality of hole portions arranged at equal intervals in the row direction and the column direction is formed (step (i)).
(I-1) Step of forming a first film on the substrate by using the actinic ray-sensitive or radiation-sensitive resin composition (1) (i-2) Step of exposing the first film (i- 3) Step of developing the exposed first film using a developer to form a first pattern

<Step (i-1): Formation of first film>
The substrate on which the first film is formed is not particularly limited, and is an inorganic substrate such as silicon, SiN, SiO ₂ or SiN, a coated inorganic substrate such as SOG, a semiconductor manufacturing process such as an IC, a liquid crystal, a thermal A substrate generally used in a manufacturing process of a circuit board such as a head, and also in other photo-fabrication lithography processes can be used. Furthermore, if necessary, an underlayer film such as an antireflection film may be formed between the first film and the substrate. As the lower layer film, an organic antireflection film, an inorganic antireflection film, and the like can be appropriately selected. The underlayer film material is available from Brewer Science, Nissan Chemical Industries, Ltd. Examples of the lower layer film suitable for the process of developing using a developer containing an organic solvent include the lower layer film described in International Patent Publication No. 2012/039337.

In the step (i-1), the method of forming the first film using the actinic ray-sensitive or radiation-sensitive resin composition (1) typically comprises an actinic ray-sensitive or radiation-sensitive resin composition. The material (1) can be applied on the substrate, and as a coating method, a conventionally known spin coating method, spray method, roller coating method, dipping method or the like can be used. An actinic ray-sensitive or radiation-sensitive resin composition (1) is applied.
The actinic ray-sensitive or radiation-sensitive resin composition (1) will be described later in detail.

The thickness of the first film is preferably 20 to 1500 nm, more preferably 50 to 1500 nm, and still more preferably 60 to 1500 nm.
In particular, when a light source having a wavelength of 1 to 200 nm (specifically, an ArF excimer laser described later) is used, the thickness of the first film is preferably 20 to 500 nm, preferably 60 to 300 nm. More preferably it is.
In addition, when a light source having a wavelength of more than 200 nm and not more than 250 nm (specifically, a KrF excimer laser described later) is used, the thickness of the first film is preferably 200 to 1500 nm, and preferably 300 to 1200 nm. It is more preferable that the thickness is 300 to 1000 nm.

<Pre-heating step and post-exposure heating step>
The pattern forming method of the present invention preferably includes a preheating step (PB; Prebake) between the step (i-1) and the step (i-2).
In addition, the pattern forming method of the present invention preferably includes a post-exposure heating step (PEB; Post Exposure Bake) between the step (i-2) and the step (i-3).
The heating temperature is preferably 70 to 130 ° C., more preferably 80 to 120 ° C. for both PB and PEB.
The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds.
Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.
The reaction of the exposed part is promoted by baking, and the sensitivity and pattern profile are improved.
At least one of the preheating step and the post-exposure heating step may include a plurality of heating steps.

<Step (i-2): Exposure of first film>
In the exposure of step (i-2), the wavelength of the light source used in the exposure apparatus is not limited, but examples include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Preferably, far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, EUV (13 nm), electron beam, and the like, preferably KrF excimer laser, ArF excimer laser, EUV or electron beam.
Step (i-2) may include a plurality of exposure steps.

For example, when the light source is a KrF excimer laser, an ArF excimer laser, or EUV, it is preferable to irradiate (that is, expose) active light or radiation through a mask.
In this embodiment, for example, a hole pattern mask (not shown) having a plurality of hole portions arranged at equal intervals in the row direction and the column direction can be used as the light shielding portion.
However, in the present invention, the mask used in the step (i-2) is not limited to this, and can be appropriately selected according to the desired shape of the first pattern. It is also possible to use a mask having a line-and-space pattern having a space part as a transmissive part and having a ratio of the width of the line part to the width of the space part of 1: 1.

In the exposure of step (i-2), an immersion exposure method may be applied.
The immersion exposure method is a technique for increasing the resolving power and performing exposure by filling a space between a projection lens and a sample with a liquid having a high refractive index (hereinafter also referred to as “immersion liquid”). In addition, immersion exposure can be combined with super-resolution techniques such as phase shift method and modified illumination method.

When performing immersion exposure, (1) after the first film is formed on the substrate, before the exposure step and / or (2) the first film is exposed via the immersion liquid. After the step, before the step of heating the first film, a step of washing the surface of the first film with a chemical solution may be performed.

The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the first film. It is preferable to use water from the viewpoint of easy availability and ease of handling.

When water is used, an additive (liquid) that reduces the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens element.
As such an additive, for example, an aliphatic alcohol having a refractive index substantially equal to that of water is preferable, and specific examples include methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained.

On the other hand, when an opaque material or impurities whose refractive index is significantly different from water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. In order to avoid this, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive that increases the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

When the first film formed using the actinic ray-sensitive or radiation-sensitive resin composition (1) is exposed through an immersion medium, the hydrophobic resin (D) described later is further provided as necessary. Can be added. By adding the hydrophobic resin (D), the receding contact angle of the surface is improved. The receding contact angle of the first film is preferably 60 ° to 90 °, more preferably 70 ° or more.
In the immersion exposure process, the immersion head needs to move on the wafer following the movement of the exposure head scanning the wafer at high speed to form the exposure pattern, so that the dynamic state is reached. The contact angle of the immersion liquid with respect to the resist film (first film) is important. For this reason, the resist is required to have the capability of following the high-speed scanning of the exposure head without any remaining droplets.

The first film is not directly brought into contact with the immersion liquid between the first film formed using the actinic ray-sensitive or radiation-sensitive resin composition (1) of the present invention and the immersion liquid. Therefore, an immersion liquid hardly soluble film (hereinafter, also referred to as “top coat”) may be provided. Functions necessary for the top coat include suitability for application to the resist upper layer, transparency to radiation, particularly radiation having a wavelength of 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of transparency at 193 nm, the topcoat is preferably a polymer that does not contain aromatics.
Specific examples include hydrocarbon polymers, acrylic ester polymers, polymethacrylic acid, polyacrylic acid, polyvinyl ether, silicon-containing polymers, and fluorine-containing polymers. The hydrophobic resin (D) is also suitable as a top coat. When impurities are eluted from the top coat into the immersion liquid, the optical lens is contaminated. Therefore, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the first film is preferable. It is preferable that the peeling process can be carried out with an alkali developer in that the peeling process can be performed simultaneously with the development process of the first film. The top coat is preferably acidic from the viewpoint of peeling with an alkali developer, but may be neutral or alkaline from the viewpoint of non-intermixability with the first film.
There is preferably no or small difference in refractive index between the top coat and the immersion liquid. In this case, the resolution can be improved. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid. Therefore, the top coat for ArF immersion exposure is close to the refractive index of water (1.44). preferable. Moreover, it is preferable that a topcoat is a thin film from a viewpoint of transparency and refractive index.

It is preferable that the top coat is not mixed with the first film and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the solvent used for the topcoat is preferably a water-insoluble medium that is hardly soluble in the solvent used for the resin composition in the present invention. . Further, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

<Step (i-3): Development of first film>
In the step (i-3), the developer in the step of developing the first film with a developer to form the first pattern includes a developer containing an organic solvent (hereinafter referred to as an organic developer). Or an alkaline developer may be used. From the viewpoint that a fine negative pattern can be formed, it is preferable to use an organic developer.
As the organic developer, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.
Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, Examples include cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, and propylene carbonate.
Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, isoamyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol Monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, Examples thereof include butyl lactate, propyl lactate, and butyl butanoate.
Examples of the alcohol solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, alcohols such as n-octyl alcohol and n-decanol, glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, Diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butano It can be mentioned glycol ether solvents such as Le.
Examples of the ether solvent include dioxane, tetrahydrofuran, phenetole, dibutyl ether and the like in addition to the glycol ether solvent.
Examples of amide solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be used.
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, and undecane.
A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than those described above or water. However, in order to fully exhibit the effects of the present invention, the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of moisture.
That is, the content of the organic solvent with respect to the organic developer is preferably more than 50% by mass and 100% by mass or less, and more preferably 70% by mass to 100% by mass with respect to the total amount of the developer. Preferably, it is 90 mass% or more and 100 mass% or less, More preferably, 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 ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. .

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, the evaporation of the developer on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimensions in the wafer surface are uniform. Sexuality improves.
Specific examples having a vapor pressure of 5 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 2-heptanone (methyl amyl ketone), 4-heptanone, 2-hexanone, diisobutyl ketone, Ketone solvents such as cyclohexanone, methylcyclohexanone, phenylacetone, methyl isobutyl ketone, butyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol Monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl -3-Methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate and other ester solvents, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, Alcohol solvents such as isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, glycol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl Ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene Glycol ether solvents such as recall monoethyl ether and methoxymethylbutanol, ether solvents such as tetrahydrofuran, phenetol and dibutyl ether, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide amide And aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as octane and decane.
Specific examples having a vapor pressure of 2 kPa or less, which is a particularly preferable range, include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone. , Ketone solvents such as phenylacetone, butyl acetate, amyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3- Ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate, propyl lactate, etc. Ester solvents, alcohol solvents such as n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, ethylene glycol, diethylene glycol , Glycol solvents such as triethylene glycol, and glycols such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol Ether solvents, ether solvents such as phenetol and dibutyl ether, N-methyl- - pyrrolidone, N, N- dimethylacetamide, N, N-dimethylformamide amide solvents, aromatic hydrocarbon solvents such as xylene, octane, aliphatic hydrocarbon solvents decane.

An appropriate amount of a surfactant can be added to the organic developer as required.
The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No. 5,405,720, The surfactants described in US Pat. Nos. 5,360,692, 5,298,881, 5,296,330, 5,346,098, 5,576,143, 5,294,511, and 5,824,451 can be mentioned. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.
The amount of the surfactant used is usually from 0.001 to 5% by mass, preferably from 0.005 to 2% by mass, more preferably from 0.01 to 0.5% by mass, based on the total amount of the developer.
Further, an embodiment in which a nitrogen-containing compound (amine or the like) is added to an organic developer as in the invention according to the claim of Japanese Patent No. 5056974 can be preferably used.

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, diethylamine, Secondary amines such as di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, and fourth amines such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions such as cyclic amines such as quaternary ammonium salts, pyrrole, and pihelidine can be used.
Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution. Examples of the surfactant include those described above. The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
In particular, an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide is desirable.

As a developing method, for example, a method in which a 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 is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously discharging the developer while scanning the developer discharge nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc. can be applied.
When the various development methods described above include a step of discharging the developer from the developing nozzle of the developing device toward the resist film, the discharge pressure of the discharged developer (the flow rate per unit area of the discharged developer) is Preferably it is 2 mL / sec / mm ² or less, More preferably, it is 1.5 mL / sec / mm ² or less, More preferably, it is 1 mL / sec / mm ² or less. There is no particular lower limit on the flow rate, but 0.2 mL / sec / mm ² or more is preferable in consideration of throughput.
By setting the discharge pressure of the discharged developer to be in the above range, pattern defects derived from the resist residue after development can be remarkably reduced. This is described in detail in JP2010-232550A.
The developer discharge pressure (mL / sec / mm ² ) is a value at the developing nozzle outlet in the developing device.

Examples of the method for adjusting the discharge pressure of the developer include a method of adjusting the discharge pressure with a pump or the like, and a method of changing the pressure by adjusting the pressure by supply from a pressurized tank.

In addition, after the step of developing using a developer, a step of stopping development may be performed while substituting with another solvent.

<Rinse process>
The pattern forming method of the present invention is performed between step (i-3) and step (iii) (when step (ii) described later is performed, between step (i-3) and step (ii)). That is, it is preferable to include a step of rinsing with a rinsing solution (rinsing step) after the step of developing with a developing solution.

The rinsing liquid is not particularly limited as long as the resist pattern is not dissolved. As the rinse liquid, a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. It is preferable.
Specific examples of the hydrocarbon solvent, the ketone solvent, the ester solvent, the alcohol solvent, the amide solvent, and the ether solvent are the same as those described in the developer containing an organic solvent.
Here, examples of the monohydric alcohol used in the rinsing step include linear, branched, and cyclic monohydric alcohols. Specific examples include 1-butanol, 2-butanol, and 3-methyl-1-butanol. 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, and particularly preferable monohydric alcohols having 5 or more carbon atoms are 1-hexanol, 2-hexanol, 4-methyl- Use 2-pentanol, 1-pentanol, 3-methyl-1-butanol, etc. It can be.
Here, the hydrocarbon solvent used in the rinsing step is preferably an aliphatic hydrocarbon solvent such as pentane, hexane, octane, decane, or undecane, and more preferably an aliphatic hydrocarbon solvent having 10 or more carbon atoms such as undecane. Is more preferable.

A plurality of the above components may be mixed, or may be used by mixing with an organic solvent other than the above.

When the rinse liquid contains an organic solvent, the water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.

The vapor pressure of the rinse liquid is preferably 0.05 kPa or more and 5 kPa or less at 20 ° C., more preferably 0.1 kPa or more and 5 kPa or less, and most preferably 0.12 kPa or more and 3 kPa or less. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinse solution is suppressed, and the dimensional uniformity in the wafer surface. Improves.
As the rinsing liquid, water or an aqueous solution may be used, and pure water is preferable. A surfactant may be added to the aqueous rinse solution.

The cleaning method in the rinsing step is not particularly limited. For example, a method of continuously discharging a rinsing liquid onto a substrate rotating at a constant speed (rotary coating method), a substrate in a bath filled with the rinsing liquid Can be applied for a certain period of time (dip method), a method of spraying a rinsing liquid on the substrate surface (spray method), etc. Among them, a cleaning process is performed by a spin coating method, and the substrate is washed at 2000 rpm or more after cleaning. It is preferable to rotate at a rotational speed of 4000 rpm to remove the rinse liquid from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developing solution and the rinsing solution remaining between the patterns and inside the patterns are removed by baking. The heating step after the rinsing step is usually performed at 40 to 160 ° C., preferably 70 to 95 ° C., usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

Further, after the developing process or the rinsing process, it is possible to perform a process of removing the developing solution or the rinsing liquid adhering to the pattern with a supercritical fluid.

<Process (ii): Heating process>
As shown in FIGS. 1B and 2B, a heating step (ii) may be further performed between the step (i-3) and the step (iii) described in detail later. .
Thereby, the solvent resistance of the first pattern formed in the step (i-3) can be further improved, and in the subsequent step (iii), the actinic ray-sensitive or radiation-sensitive resin is formed on the first pattern. Even if the liquid made of the composition (2) is applied, it can be converted into the first pattern 52 which is not easily damaged. This effect is remarkable when an organic developer is used in step (i-3).
The temperature in this heating step is preferably 150 ° C. or higher, and more preferably 170 ° C. or higher. The said temperature is normally made into 240 degrees C or less. The heating time in this heating step is about 30 to 120 seconds. It is preferable that the heating step be performed in such a temperature range and time, since it is considered that the decomposition residue of the organic matter volatilizes and becomes insoluble in the solvent.

Note that the present invention does not exclude applying a known freezing material to the first pattern 51 or the first pattern 52.

<Step (iii): Formation of Second Film>
Next, as shown in FIGS. 1C and 2C, a resist film (second film) is formed on the first pattern 52 by using the actinic ray-sensitive or radiation-sensitive resin composition (2). Film) 60 is formed (step (iii)).
The actinic ray-sensitive or radiation-sensitive resin composition (2) will be described in detail later.

In the step (iii), the second film 60 may be formed at least on the film portion of the first pattern 52, and the film portion of the first pattern 52 on the substrate 10 is formed. The second film 60 may or may not be formed in the region that has not been formed.
However, as will be described later, the method of forming the second film using the actinic ray-sensitive or radiation-sensitive resin composition (2) is typically an actinic ray-sensitive or radiation-sensitive resin composition. It can be carried out by applying (2). For this reason, in the step (iii), if the second film 60 is not formed on the substrate 10 in the region where the film portion of the first pattern 52 is not formed, the work may be complicated.
Therefore, in the step (iii), as shown in FIG. 2C, the second film 60 is also formed in the region where the film portion of the first pattern 52 on the substrate 10 is not formed. preferable.

Further, the second film 60 may be formed not only on the entire surface of the film portion of the first pattern 52 but only on a part of the surface of the film portion of the first pattern 52. Good.

In the step (iii), the method of forming the second film using the actinic ray-sensitive or radiation-sensitive resin composition (2) is the same as the step (i-1) in which the actinic ray-sensitive or radiation-sensitive resin is formed. This is the same as the method for forming the first film using the composition (1).

The preferable range of the thickness of the second film is the same as that described as the preferable range of the thickness of the first film. The film thickness of the second film may be the same as or different from the film thickness of the first film.
The film thickness of the second film here means the film thickness of the second film formed on the first pattern, and the film portion of the first pattern on the substrate is formed. The second film formed in a non-existing region is not considered.

<Pre-heating step and post-exposure heating step>
The pattern forming method of the present invention preferably includes a preheating step (PB; Prebake) between the step (iii) and the step (v).
Moreover, it is also preferable that the pattern formation method of this invention includes the post-exposure heating process (PEB; Post Exposure Bake) between the process (v) and the process (vi). The heating temperature is preferably 70 to 130 ° C., more preferably 80 to 120 ° C. for both PB and PEB.
The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds.
Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.
The reaction of the exposed part is promoted by baking, and the sensitivity and pattern profile are improved.
At least one of the preheating step and the post-exposure heating step may include a plurality of heating steps.

<Step (v): Exposure of second film>
Next, the second film 60 is irradiated with actinic rays or radiation (that is, exposed) to obtain an exposed second film 60 (step (v)).
As above, for example, when the light source is a KrF excimer laser, an ArF excimer laser, or EUV, it is preferable to irradiate (that is, expose) actinic rays or radiation through a mask (not shown).
The mask pattern in the mask of the step (v) is not particularly limited, but in this embodiment, a mask different from the mask used in the step (i-2) is used.
Specifically, the mask has a line-and-space pattern having a line part as a light-shielding part and a space part as a light transmission part, and the ratio of the width of the line part to the width of the space part is 1: 1. A mask (not shown) is used in such a state that the light shielding portion of the mask covers each of the hole portions of the first pattern 52.
However, like the mask used in step (i-2), the mask in step (v) is not limited to the above-described mask, and can be appropriately selected according to the desired shape of the second pattern.

As the exposure method in step (v), the same method as described in the exposure in step (i-2) can be employed. From the viewpoint of improving throughput, the exposure light source in step (v) is preferably the same as the exposure light source in step (i-2).

<Step (vi): Development of second film (formation of second pattern)>
Next, the exposed second film 60 is developed using a developing solution to form a second pattern 61 as shown in FIGS. 1D and 2D (step (vi)).
As the developer in the step (vi), the same organic developer and alkali developer as described in the step (i-3) can be used, and an organic developer is preferably used.

As described above, the second film 60 is formed on at least the first pattern 52. Therefore, in the step (vi), the second pattern 61 is similarly formed on at least the first pattern 52.
In the present embodiment, as shown in FIG. 1D and FIG. 2D, a space portion is positioned on the hole portion on the hole pattern (first pattern 52) having a plurality of hole portions, and the holes are formed. A line and space pattern (second pattern 61) is formed so that the portion is exposed.
Thus, according to the present embodiment, a multistage resist pattern having a multistage structure including the first pattern 52 that is a hole pattern and the second pattern 61 that is a line and space pattern is formed on the substrate 10.
Needless to say, the multistage resist pattern formed by the pattern forming method of the present invention is not limited to this.

<Rinse process>
Moreover, it is preferable that the pattern formation method of this invention includes the process (rinsing process) wash | cleaned using a rinse liquid after a process (vi). As the rinse liquid in this case, the above-described rinse liquid can be used.

The cleaning treatment methods in these rinsing steps can be the same as those described above.

<Heating step (ii) '>
The pattern forming method of the present invention may include a heating step (ii) ′ after the step (vi), that is, after the step of developing using a developer. The heating step (ii) ′ is preferably performed after the step (vi) and before an etching process described later.
What was demonstrated in the heating process (ii) mentioned above can be employ | adopted for various conditions (heating temperature, heating time, etc.) in heating process (ii) '.

<Etching process>
Next, etching is performed on the substrate 10 using the pattern formed as described above (that is, a multistage resist pattern including the first pattern 52 and the second pattern 61) as a mask.

At this time, by performing a known etching process (for example, a dry etching process) that can etch the substrate 10 with the multi-stage resist pattern including the first pattern 52 and the second pattern 61, FIG. As shown in FIG. 2E, the substrate 10 in which positions corresponding to the hole portions of the first pattern 52 and the space portions of the second pattern 61 are perforated is obtained.

Note that the method for the etching treatment is not particularly limited, and any known method can be used, and various conditions and the like are appropriately determined according to the type and use of the substrate. For example, Bulletin of the International Society of Optical Engineering (Proc. Of SPIE) Vol. 6924, 692420 (2008), Japanese Patent Application Laid-Open No. 2009-267112, and the like can be performed.

<Modification>
Further, the first pattern in the present embodiment described above may be formed by patterning the resist film twice or more.
In other words, the step (i) of forming the first pattern includes a plurality of pattern formation steps including the step (i-1), the step (i-2), and the step (i-3) in this order. It may be included (this form is also referred to as a modified example hereinafter).
In this case, a plurality of pattern forming steps may further include a heating step between two successive pattern forming steps.

Hereinafter, the modified example will be specifically described.
First, by performing the step (i-1), the step (i-2) and the step (i-3) in this order by the same method as described above, a first pattern is formed on the substrate as, for example, A line and space pattern (not shown) having a line width and a space width of 1: 3 is formed.

Next, a heating step (a so-called freezing step) may be performed, whereby the solvent resistance of the line and space pattern can be further improved. Thereby, even if another actinic ray-sensitive or radiation-sensitive resin composition (1) is subsequently applied to the region of the substrate where the film portion of the line and space pattern is not formed, it is not easily damaged. Line and space patterns can be formed. In addition, what was demonstrated in the heating process (ii) mentioned above is employable as various conditions of a heating process.

Next, by performing the step (i-1), the step (i-2) and the step (i-3) in this order on the region of the substrate where the film part of the line and space pattern is not formed, As the first pattern, for example, a line and space pattern having a line width and a space width of 1: 3 is formed.
As a result, the line and space pattern formed in the previous pattern formation process and the line and space pattern formed in the subsequent pattern formation process are formed on the substrate. A 1: 1 first pattern is formed.
Next, a heating step (a so-called freezing step) may be performed.

And the pattern formation method of this invention can be implemented by performing the process demonstrated after FIG.1 (c) and FIG.2 (c) with respect to the 1st pattern obtained in this way.

As described above, the pattern forming method and the etching method according to the embodiment of the present invention have been described. However, according to the present invention, it is possible to form multi-stage patterns having various shapes on a substrate by etching or the like.
The pattern forming method of the present invention can be suitably applied to, for example, a dual damascene process for forming a multistage pattern.

In addition, the pattern obtained by the pattern forming method of the present invention is applied to a spacer process core material (core) as disclosed in JP-A-3-270227 and JP-A-2013-164509. Is also possible. Furthermore, it can be suitably used for guide pattern formation in DSA (Directed Self-Assembly) (for example, refer to ACS NanoVol.4 No.8 Page4815-4823). In addition, application to various uses is possible.

The present invention also relates to a method for manufacturing an electronic device, including the pattern forming method of the present invention described above.
The manufactured electronic device is preferably mounted on an electric / electronic device (home appliance, OA / media related device, optical device, communication device, etc.).

<Actinic ray-sensitive or radiation-sensitive resin composition (1)>
Next, each component of the actinic ray-sensitive or radiation-sensitive resin composition (1) (also simply referred to as “resin composition (1)”) used in the pattern forming method of the present invention will be described.
The actinic ray-sensitive or radiation-sensitive resin composition (1) is typically a resist composition, and preferably a chemically amplified resist composition.
The chemically amplified resist composition may be a cross-linked resist composition in which the solubility of the resist film in the developer is changed by a cross-linking reaction, or an acid in which the solubility of the resist film in the developer is changed by an acid decomposition reaction. A decomposable resist composition may be used. The cross-linked resist composition typically contains an alkali-soluble resin, a cross-linking agent, and a photoacid generator. The acid-decomposable resist composition typically contains a resin whose polarity increases by the action of an acid and changes its solubility in a developer, and a compound that generates an acid upon irradiation with actinic rays or radiation.
In one embodiment, the resin composition (1) is preferably an acid-decomposable resist composition. Hereinafter, each component contained in the resin composition (1) will be described.

[1] Resin whose polarity increases due to the action of an acid and changes in solubility in a developer The resin whose polarity increases due to the action of an acid and whose solubility in a developer changes, includes, for example, the main chain or side chain of the resin, Alternatively, a resin (hereinafter referred to as “acid-decomposable resin” or “resin” having a group (hereinafter also referred to as “acid-decomposable group”) that is decomposed by the action of an acid to generate a polar group in both the main chain and the side chain. (A) ").
The acid-decomposable group preferably has a structure protected by a group capable of decomposing and leaving a polar group by the action of an acid. Preferable polar groups include a carboxyl group, a phenolic hydroxyl group, an alcoholic hydroxyl group (alcoholic means that it does not show acidity like a so-called phenolic hydroxyl group), and a sulfonic acid group.

A preferable group as the acid-decomposable group is a group in which the hydrogen atom of these groups is substituted with a group capable of leaving with an acid.
Examples of the group leaving with an 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, each of R ₃₆ to R ₃₉ independently represents an alkyl group, a cycloalkyl group (monocyclic or polycyclic), 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 represents a hydrogen atom, an alkyl group (monocyclic or polycyclic), a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group. Further, when the pattern forming method of the present invention is performed by exposure with KrF light or EUV light, or electron beam irradiation, it is also preferable to use an acid-decomposable group in which a phenolic hydroxyl group is protected with an acid leaving group.

The resin (A) preferably has a repeating unit having an acid-decomposable group.
Examples of this repeating unit include the following.

In general formulas (aI) and (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 represents an alkyl group or a cycloalkyl group. Two of Rx ₁ to Rx ₃ may combine to form a ring structure. The ring structure may contain a hetero atom such as an oxygen atom in the ring.
Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, phenylene group and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.

T in the general formula (aI) is preferably a single bond or a —COO—Rt— group, more preferably a —COO—Rt— group, from the viewpoint of insolubilization of the resist in an organic solvent developer. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a —CH ₂ — group, — (CH ₂ ) ₂ — group, or — (CH ₂ ) ₃ — group.
T in the general formula (aI ′) is preferably a single bond.

The alkyl group of _Xa1 may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (preferably a fluorine atom).
The alkyl group for X _a1 preferably has 1 to 4 carbon atoms, and more preferably a methyl group.
X _a1 is preferably a hydrogen atom or a methyl group.
The alkyl group for Rx ₁ , Rx ₂ and Rx ₃ may be linear or branched.
Examples of the cycloalkyl group of Rx ₁ , Rx ₂ and Rx ₃ include polycyclic rings such as a monocyclic cycloalkyl group such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group and adamantyl group. Are preferred.
The ring structure formed by combining two of Rx ₁ , Rx ₂ and Rx ₃ includes a monocyclic cycloalkane ring such as cyclopentyl ring and cyclohexyl ring, norbornane ring, tetracyclodecane ring, tetracyclododecane ring, adamantane ring A polycyclic cycloalkyl group such as is preferable. A monocyclic cycloalkane ring having 5 or 6 carbon atoms is particularly preferable.
Rx ₁ , Rx ₂ and Rx ₃ are preferably each independently an alkyl group, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (1 to 4 carbon atoms), a cycloalkyl group (3 to 8 carbon atoms), a halogen atom, an alkoxy group (carbon 1 to 4), a carboxyl group, an alkoxycarbonyl group (2 to 6 carbon atoms), and the like, and 8 or less carbon atoms are preferable. Among these, from the viewpoint of further improving the dissolution contrast with respect to a developer containing an organic solvent before and after acid decomposition, a substituent having no hetero atom such as an oxygen atom, a nitrogen atom, or a sulfur atom is more preferable ( For example, it is more preferable that it is not an alkyl group substituted with a hydroxyl group, etc.), a group consisting of only a hydrogen atom and a carbon atom is more preferable, and a linear or branched alkyl group or a cycloalkyl group is particularly preferable. preferable.

When the composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, or high-energy light (for example, EUV) having a wavelength of 50 nm or less, the resin (A) has a hydroxystyrene repeating unit. It is preferable. More preferably, the resin (A) is a copolymer of hydroxystyrene and hydroxystyrene protected with a group capable of leaving by the action of an acid, or hydroxystyrene and a (meth) acrylic acid tertiary alkyl ester. It is a copolymer.
Specific examples of such a resin include a resin having a repeating unit represented by the following general formula (A).

In the formula, R ₀₁ , R ₀₂ and R ₀₃ each independently represent, for example, a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Ar ₁ represents an aromatic ring group, for example. Note that R ₀₃ and Ar ₁ are alkylene groups, and they may be bonded to each other to form a 5-membered or 6-membered ring together with the —C—C— chain.
n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of Y represents a group capable of leaving by the action of an acid.
n represents an integer of 1 to 4, preferably 1 to 2, and more preferably 1.

The alkyl group as R ₀₁ to R ₀₃ is, for example, an alkyl group having 20 or less carbon atoms, and preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a hexyl group. 2-ethylhexyl group, octyl group or dodecyl group. More preferably, these alkyl groups are alkyl groups having 8 or less carbon atoms. In addition, these alkyl groups may have a substituent.
As the alkyl group contained in the alkoxycarbonyl group, the same alkyl groups as those described above for R ₀₁ to R ₀₃ are preferable.
The cycloalkyl group may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. Preferably, monocyclic cycloalkyl groups having 3 to 8 carbon atoms such as cyclopropyl group, cyclopentyl group, and cyclohexyl group are exemplified. In addition, these cycloalkyl groups may have a substituent.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is more preferable.

When R ₀₃ represents an alkylene group, the alkylene group is preferably an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group.
The aromatic ring group as Ar ₁ preferably has 6 to 14 carbon atoms, and examples thereof include a benzene ring, a toluene ring, and a naphthalene ring. In addition, these aromatic ring groups may have a substituent.
Examples of the group Y leaving by the action of an acid include —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (═O) —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ). ), —C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ), —C (R ₀₁ ) (R ₀₂ ) —C (═O) —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ) or And a group represented by —CH (R ₃₆ ) (Ar).
In the formula, R ₃₆ to R ₃₉ each independently represents 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 structure.
R ₀₁ and R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
Ar represents an aryl group.

The alkyl group as R ₃₆ to R ₃₉ , R ₀₁ , or R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- A butyl group, a hexyl group, and an octyl group are mentioned.
The cycloalkyl group as R ₃₆ to R ₃₉ , R ₀₁ , or R ₀₂ may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. The monocyclic cycloalkyl group is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. The polycyclic cycloalkyl group is preferably a cycloalkyl group having 6 to 20 carbon atoms, such as an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinanyl group, tricyclodecanyl group, A tetracyclododecyl group and an androstanyl group are mentioned. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
The aryl group as R ₃₆ to R ₃₉ , R ₀₁ , R ₀₂ , or Ar 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 as R ₃₆ to R ₃₉ , R ₀₁ , or R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and for example, a benzyl group, a phenethyl group, and a naphthylmethyl group are preferable.
The alkenyl group as R ₃₆ to R ₃₉ , R ₀₁ , or 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 that R ₃₆ and R ₃₇ may be bonded to each other may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkane structure having 3 to 8 carbon atoms, and examples thereof include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure. The polycyclic type is preferably a cycloalkane structure having 6 to 20 carbon atoms, and examples thereof include an adamantane structure, a norbornane structure, a dicyclopentane structure, a tricyclodecane structure, and a tetracyclododecane structure. Note that some of the carbon atoms in the ring structure may be substituted with a heteroatom such as an oxygen atom.
Each of the above groups may have a substituent. Examples of this substituent include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, and acyloxy groups. , Alkoxycarbonyl group, cyano group and nitro group. These substituents preferably have 8 or less carbon atoms.
As the group Y leaving by the action of an acid, a structure represented by the following general formula (B) is more preferable.

In the formula, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alkyl group, a cycloalkyl group, a cycloaliphatic group, an aromatic ring group, an amino group, an ammonium group, a mercapto group, a cyano group, or an aldehyde group. In addition, these cycloaliphatic groups and aromatic ring groups may contain a hetero atom.
In addition, at least two of Q, M, and L ₁ may be bonded to each other to form a 5-membered or 6-membered ring.

The alkyl group as L ₁ and L ₂ is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, and An octyl group is mentioned.
The cycloalkyl group as L ₁ and L ₂ is, for example, a cycloalkyl group having 3 to 15 carbon atoms, and specific examples include a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.
The aryl group as L ₁ and L ₂ is, for example, an aryl group having 6 to 15 carbon atoms, and specific examples include a phenyl group, a tolyl group, a naphthyl group, and an anthryl group.
The aralkyl group as L ₁ and L ₂ is, for example, an aralkyl group having 6 to 20 carbon atoms, and specific examples include a benzyl group and a phenethyl group.

The divalent linking group as M is, for example, an alkylene group (for example, methylene group, ethylene group, propylene group, butylene group, hexylene group or octylene group), cycloalkylene group (for example, cyclopentylene group or cyclohexylene group). ), Alkenylene group (for example, ethylene group, propenylene group or butenylene group), arylene group (for example, phenylene group, tolylene group or naphthylene group), —S—, —O—, —CO—, —SO ₂ —, — N (R ₀ ) — or a combination of two or more thereof. Here, R ₀ is a hydrogen atom or an alkyl group. The alkyl group as R ₀ is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, and an octyl group. Can be mentioned.

The alkyl group and cycloalkyl group as Q are the same as the above-described groups as L ₁ and L ₂ .
Examples of the cyclic aliphatic group or aromatic ring group as Q include the cycloalkyl group and aryl group as L ₁ and L ₂ described above. These cycloalkyl group and aryl group are preferably groups having 3 to 15 carbon atoms.
Examples of the cycloaliphatic group or aromatic ring group containing a hetero atom as Q include thiirane, cyclothiolane, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, And groups having a heterocyclic structure such as thiazole and pyrrolidone. However, the ring is not limited to these as long as it is a ring formed of carbon and a heteroatom, or a ring formed only of a heteroatom.
Examples of the ring structure that can be formed by bonding at least two of Q, M, and L ₁ to each other include a 5-membered or 6-membered ring structure in which these form a propylene group or a butylene group. This 5-membered or 6-membered ring structure contains an oxygen atom.

Each group represented by L ₁ , L ₂ , M and Q in the general formula (B) may have a substituent. Examples of this substituent include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, and acyloxy groups. , Alkoxycarbonyl group, cyano group and nitro group. These substituents preferably have 8 or less carbon atoms.
The group represented by — (MQ) is preferably a group having 1 to 20 carbon atoms, more preferably a group having 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms.

Although the specific example of the repeating unit which has an acid-decomposable group is given, it is not limited to these.
In specific examples, Rx represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rxa and Rxb each represents an alkyl group having 1 to 4 carbon atoms. Xa ₁ represents a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Z represents a substituent, and when a plurality of Zs are present, the plurality of Zs may be the same as or different from each other. p represents 0 or a positive integer. Specific examples and preferred examples of Z are the same as specific examples and preferred examples of the substituent that each group such as Rx ₁ to Rx ₃ may have.

In the specific examples below, Xa represents a hydrogen atom, an alkyl group, a cyano group or a halogen atom.

One type of repeating unit having an acid-decomposable group may be used, or two or more types may be used in combination. When two types are used in combination, the combination is not particularly limited. For example, (1) a repeating unit that decomposes by the action of an acid to generate a carboxyl group and a repeating unit that decomposes by the action of an acid to generate an alcoholic hydroxyl group (2) A combination of a repeating unit that decomposes by the action of an acid to generate a carboxyl group and a repeating unit that decomposes by the action of an acid to generate a phenolic hydroxyl group, (3) Decomposed by the action of an acid Thus, a combination of two types of repeating units that generate a carboxyl group (having different structures) can be considered. Among these, the preferable combination in the case of (3) is illustrated for reference.

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 not particularly limited. The lower limit of the unit is preferably 15 mol% or more, more preferably 20 mol% or more, further preferably 25 mol% or more, and particularly preferably 40 mol% or more. . Moreover, as an upper limit, it is preferable that it is 90 mol% or less, It is more preferable that it is 75 mol% or less, It is more preferable that it is 65 mol% or less.

The resin (A) may contain a repeating unit having a lactone structure or a sultone structure.
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.

It is also possible to use a repeating unit having two or more lactone structures or sultone structures in combination.

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 5 to 60 mol% with respect to all the repeating units in the resin (A). It is preferably 5 to 55 mol%, more preferably 10 to 50 mol%.

Moreover, the resin (A) may have a repeating unit having a cyclic carbonate structure. Specific examples are given below, but the present invention is not limited thereto.
In the following specific examples, R _A ¹ represents a hydrogen atom or an alkyl group (preferably a methyl group).

When the resin (A) contains a repeating unit having a cyclic carbonate structure, the content of the repeating unit having a cyclic carbonate structure is preferably 5 to 60 mol% with respect to all the repeating units in the resin (A). More preferably, it is 5 to 55 mol%, still more preferably 10 to 50 mol%.

The resin (A) may have a repeating unit having a hydroxyl group or a cyano group.
Specific examples of the repeating unit having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

When the resin (A) contains a repeating unit having a hydroxyl group or a cyano group, the content of the repeating unit having a hydroxyl group or a cyano group is preferably from 3 to 25 mol% based on all repeating units in the resin (A). More preferably, it is 5 to 15 mol%.

Resin (A) may have a repeating unit having an acid group.
The resin (A) may or may not contain a repeating unit having an acid group, but when it is contained, the content of the repeating unit having an acid group is relative to all the repeating units in the resin (A). It is preferably 25 mol% or less, and more preferably 20 mol% or less. When resin (A) contains the repeating unit which has an acid group, content of the repeating unit which has an acid group in resin (A) is 1 mol% or more normally.

Specific examples of the repeating unit having an acid group are shown below, but the present invention is not limited thereto.
In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

The resin (A) further has an alicyclic hydrocarbon structure and / or an aromatic ring structure that does not have a polar group (for example, the acid group, hydroxyl group, cyano group), and has a repeating unit that does not exhibit acid decomposability. be able to.
The content of this repeating unit is preferably 1 to 50 mol%, more preferably 5 to 50 mol%, still more preferably 5 to 30 mol%, based on all repeating units in the resin (A).
Specific examples of the repeating unit having an alicyclic hydrocarbon structure having no polar group and not exhibiting acid decomposability are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , CH ₂ OH, or CF ₃ .

As described above, in the pattern forming method of the invention, at least one of the actinic ray-sensitive or radiation-sensitive resin compositions (1) and (2) contains a resin containing a repeating unit having Si atoms.
Hereinafter, the repeating unit having Si atoms in the case where the actinic ray-sensitive or radiation-sensitive resin composition (1) contains a resin containing a repeating unit having Si atoms will be described.
The repeating unit having Si atoms is not particularly limited as long as it has Si atoms. For example, a silane repeating unit (—SiR ₂ —: R ₂ is an organic group), a siloxane repeating unit (—SiR ₂ —O—: R ₂ is an organic group), a (meth) acrylate repeating unit having a Si atom, And vinyl-based repeating units having Si atoms.

The repeating unit having a Si atom preferably has a silsesquioxane structure. In addition, although it may have a silsesquioxane structure in a main chain or in a side chain, it is preferable to have in a side chain.
Examples of the silsesquioxane structure include a cage-type silsesquioxane structure, a ladder-type silsesquioxane structure (ladder-type silsesquioxane structure), a random-type silsesquioxane structure, and the like. Of these, a cage-type silsesquioxane structure is preferable.
Here, the cage silsesquioxane structure is a silsesquioxane structure having a cage structure. The cage silsesquioxane structure may be a complete cage silsesquioxane structure or an incomplete cage silsesquioxane structure, but may be a complete cage silsesquioxane structure. preferable.
The ladder-type silsesquioxane structure is a silsesquioxane structure having a ladder-like skeleton.
The random silsesquioxane structure is a silsesquioxane structure having a random skeleton.

The cage silsesquioxane structure is preferably a siloxane structure represented by the following formula (S).

In the above formula (S), R represents a monovalent organic group. A plurality of R may be the same or different.
The organic group is not particularly limited, and specific examples include a halogen atom, a hydroxy group, a nitro group, a carboxy group, an alkoxy group, an amino group, a mercapto group, and a blocked mercapto group (for example, blocked (protected) with an acyl group). Mercapto groups), acyl groups, imide groups, phosphino groups, phosphinyl groups, silyl groups, vinyl groups, hydrocarbon groups optionally having heteroatoms, (meth) acryl group-containing groups and epoxy group-containing groups. Can be mentioned.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.
Examples of the hetero atom of the hydrocarbon group that may have a hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom.
Examples of the hydrocarbon group of the hydrocarbon group that may have a hetero atom include an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a group in which these are combined.
The aliphatic hydrocarbon group may be linear, branched or cyclic. Specific examples of the aliphatic hydrocarbon group include a linear or branched alkyl group (particularly 1 to 30 carbon atoms), a linear or branched alkenyl group (particularly 2 to 30 carbon atoms), Examples thereof include a linear or branched alkynyl group (particularly 2 to 30 carbon atoms).
Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups having 6 to 18 carbon atoms such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group.

The repeating unit having a Si atom is preferably represented by the following formula (I).

In the above 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, — (CH ₂ ) ₂ — group, or — (CH ₂ ) ₃ — group.
In the above 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 above formula (I), A represents a Si-containing group. Of these, a group represented by the following formula (a) or (b) is preferable.

In the above formula (a), R represents a monovalent organic group. A plurality of R may be the same or different. Specific examples and preferred embodiments of R are the same as those in the above formula (S). When A in the formula (I) is a group represented by the formula (a), the formula (I) is represented by the following formula (Ia).

In the above formula (b), R _b represents a hydrocarbon group which may have a hetero atom. Specific examples and preferred embodiments of the hydrocarbon group which may have a hetero atom are the same as R in the above-described formula (S).

The resin containing a repeating unit having Si atoms may contain a repeating unit having two or more kinds of Si atoms.
The content of the repeating unit having an Si atom with respect to all the repeating units of the resin is not particularly limited, but is preferably 1 to 70 mol%, and more preferably 3 to 50 mol%.
The content of Si atoms in the resin is preferably 1.0 to 30% by mass, more preferably 3.0 to 30 and even more preferably 5.0 to 30.

The form of the resin (A) in the present invention may be any of random type, block type, comb type, and star type. Resin (A) is compoundable by the radical, cation, or anion polymerization of the unsaturated monomer corresponding to each structure, for example. It is also possible to obtain the desired resin by conducting a polymer reaction after polymerization using an unsaturated monomer corresponding to the precursor of each structure.
When the resin composition (1) is used for ArF exposure, the resin (A) used for the resin composition (1) has substantially no aromatic ring from the viewpoint of transparency to ArF light (specifically Specifically, the ratio of the repeating unit having an aromatic group in the resin is preferably 5 mol% or less, more preferably 3 mol% or less, ideally 0 mol%, that is, no aromatic group. The resin (A) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.
When the resin composition (1) contains a resin (D) described later, the resin (A) preferably does not contain a fluorine atom from the viewpoint of compatibility with the resin (D).

The resin (A) used in the resin composition (1) is preferably one in which all the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units.

When the resin composition (1) is irradiated with KrF excimer laser light, electron beam, X-ray, or high-energy light (EUV, etc.) having a wavelength of 50 nm or less, the resin (A) has a repeating unit having an aromatic ring. May be. The repeating unit having an aromatic ring is not particularly limited, and is also exemplified in the above description of each repeating unit, but a styrene unit, a hydroxystyrene unit, a phenyl (meth) acrylate unit, a hydroxyphenyl (meth) acrylate. Examples include units. More specifically, the resin (A) is a resin having a hydroxystyrene-based repeating unit and a hydroxystyrene-based repeating unit protected by an acid-decomposable group, a repeating unit having the aromatic ring, and (meth) Examples thereof include a resin having a repeating unit in which the carboxylic acid moiety of acrylic acid is protected by an acid-decomposable group. In particular, particularly in the case of EUV exposure, since high sensitivity is generally required, the resin (A) preferably contains a repeating unit containing a protective group that easily undergoes acid decomposition. Specific examples of the repeating unit include -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ) or -C (R ₀₁ ) (R ₀₂ ) ( A compound represented by OR ₃₉ ) (a structure commonly referred to as an acetal type protecting group) is preferred.

The resin (A) in the present invention can be synthesized and purified according to a conventional method (for example, radical polymerization). For the synthesis method and purification method, see, for example, the descriptions in paragraphs 0201 to 0202 of JP-A-2008-292975.

The weight average molecular weight of the resin (A) in the present invention is generally 1000 or more, preferably 7,000 to 200,000, more preferably 7,000 to 50, in terms of polystyrene by GPC method. 7,000, even more preferably 7,000 to 40,000, particularly preferably 7,000 to 30,000. When the weight average molecular weight is 7000 or more, it is possible to prevent the solubility in the organic developer from becoming too high, and it is easy to form a precise pattern.

The degree of dispersion (molecular weight distribution) is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, and particularly preferably 1.4 to 2.0. Those in the range are 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 the chemically amplified resist composition of the present invention, the blending ratio of the resin (A) in the entire composition is preferably 30 to 99% by mass, more preferably 60 to 95% by mass in the total solid content.
In the present invention, the resin (A) may be used alone or in combination.

Hereinafter, specific examples of the resin (A) (the composition ratio of repeating units is a molar ratio) will be given, but the present invention is not limited to these. In addition, below, the aspect in case the structure corresponding to an acid generator (B) mentioned later is carry | supported by resin (A) is also illustrated.

The resin exemplified below is an example of a resin that can be suitably used particularly during EUV exposure or electron beam exposure.

Hereinafter, examples of resins that can be suitably used when the resin (A) includes a repeating unit having Si atoms will be shown. Here, the composition ratio of the repeating units is a molar ratio. Et represents an ethyl group, iBu represents an isobutyl group, and TMS represents a trimethylsilyl group.

[2] Compound that generates acid upon irradiation with actinic ray or radiation Resin composition (1) is usually a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter referred to as “compound (B)” or “acid generation”. Also referred to as “agent”. The compound (B) that generates an acid upon irradiation with actinic rays or radiation is preferably a compound that generates an organic acid upon irradiation with actinic rays or radiation.
As the acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, irradiation of actinic ray or radiation used for micro resist, etc. The known compounds that generate an acid and mixtures thereof can be appropriately selected and used.

Examples include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.
Among acid generators, particularly preferred examples are given below.

The acid generator can be synthesized by a known method. For example, [0200] to [0210] of JP2007-161707A, JP2010-100595A, and WO2011 / 093280 [ [0051] to [0058], [0382] to [0385] of International Publication No. 2008/153110, and the like.
An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the compound that generates an acid upon irradiation with actinic rays or radiation in the composition is preferably 0.1 to 30% by mass, more preferably 0.8%, based on the total solid content of the resin composition (1). It is 5 to 25% by mass, more preferably 3 to 20% by mass, particularly preferably 3 to 15% by mass.

In addition, depending on the actinic ray-sensitive or radiation-sensitive resin composition, there is also an embodiment (B ′) in which a structure corresponding to the acid generator is supported on the resin (A). Specifically, as such an embodiment, a structure described in JP2011-248019A (particularly, a structure described in paragraphs 0164 to 0191, a structure included in the resin described in the example in paragraph 0555). And the repeating unit (R) described in paragraphs 0023 to 0210 of JP2013-80002A, and the contents thereof are incorporated in the present specification. Incidentally, even if the structure corresponding to the acid generator is supported by the resin (A), the actinic ray-sensitive or radiation-sensitive resin composition is additionally added to the resin (A). An unsupported acid generator may be included.
Examples of the embodiment (B ′) include the following repeating units, but are not limited thereto.

[3] Solvent The resin composition (1) usually contains a solvent.
Examples of the solvent that can be used in preparing the resin composition (1) include alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactate esters, alkyl alkoxypropionates, and cyclic lactones (preferably Examples thereof include organic solvents such as monoketone compounds having 4 to 10 carbon atoms and optionally having a ring (preferably having 4 to 10 carbon atoms), alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.
Specific examples of these solvents include those described in US Patent Application Publication No. 2008/0187860 [0441] to [0455].

In the present invention, a plurality of organic solvents may be mixed and used.
For example, 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 solvent containing a hydroxyl group and the solvent not containing a hydroxyl group, the above-mentioned exemplary compounds can be selected as appropriate, but as the solvent containing a hydroxyl group, an alkylene glycol monoalkyl ether, an alkyl lactate, an alcohol solvent or the like is preferable. Specifically, propylene glycol monomethyl ether (PGME, also known as 1-methoxy-2-propanol), ethyl lactate, methyl 2-hydroxyisobutyrate, methyl isobutyl carbinol (MIBC, also known as 4-methyl-2-pentanol), 2 -Ethylbutanol is preferred. Further, as the solvent not containing a hydroxyl group, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate and the like are preferable, and among these, propylene glycol monomethyl ether Acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane), ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate are particularly preferred, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2 -Heptanone is most preferred.
Of course, organic solvents that do not contain a hydroxyl group in the structure can be used together. Examples of this combination include PGMEA and cyclohexanone, PGMEA and cyclopentanone, PGMEA and γ-butyrolactone, PGMEA and 2-heptanone, and the like.
For example, when two kinds of solvents are used, the mixing ratio (mass) is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40.
The solvent preferably contains propylene glycol monomethyl ether acetate, and is preferably a propylene glycol monomethyl ether acetate single solvent or a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.
When a suitable amount of a solvent having a relatively high boiling point such as γ-butyrolactone is used, it can be expected that the performance of the hydrophobic resin (D) described later is more unevenly distributed on the surface and the performance for immersion exposure is improved.
Furthermore, you may use 3 or more types of solvents. As a result, fine adjustment of resist shape, adjustment of viscosity, and the like may be performed. Examples of the combinations include PGMEA · PGME · γ-butyrolactone, PGMEA · PGME · cyclohexanone, PGMEA · PGME · 2-heptanone, PGMEA · cyclohexanone · γ-butyrolactone, PGMEA · γ-butyrolactone · 2-heptanone, and the like.
As the solvent, it is preferable to use a solvent having a reduced peroxide content, thereby improving the storage stability of the resist composition. The content of the peroxide in the solvent is preferably 2.0 mmol% or less, more preferably 1.0 mmol% or less, still more preferably 0.5 mmol% or less, and the peroxide. It is particularly preferable that substantially no is contained.

[4] Hydrophobic resin (D)
The resin composition (1) may contain a hydrophobic resin (hereinafter also referred to as “hydrophobic resin (D)” or simply “resin (D)”), particularly when applied to immersion exposure. The hydrophobic resin (D) is preferably different from the resin (A).
As a result, the hydrophobic resin (D) is unevenly distributed in the film surface layer, and when the immersion medium is water, the static / dynamic contact angle of the resist film surface with water is improved, and the immersion liquid followability is improved. be able to.
The hydrophobic resin (D) may be included for various purposes even when the resin composition (1) is not applied to immersion exposure. For example, when applying the resin composition (1) to EUV exposure, it is also preferable to use the hydrophobic resin (D) in anticipation of outgas suppression and pattern shape adjustment.
The hydrophobic resin (D) is preferably designed to be unevenly distributed at the interface as described above. However, unlike the surfactant, the hydrophobic resin (D) does not necessarily need to have a hydrophilic group in the molecule. There is no need to contribute to uniform mixing.

The hydrophobic resin (D) is selected from any one of “fluorine atom”, “silicon atom”, and “CH ₃ partial structure contained in the side chain portion of the resin” from the viewpoint of uneven distribution in the film surface layer. It is preferable to have the above, and it is more preferable to have two or more.

The weight average molecular weight in terms of standard polystyrene of the hydrophobic resin (D) is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 15,000. is there.
In addition, the hydrophobic resin (D) may be used alone or in combination.
The content of the hydrophobic resin (D) in the composition is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, based on the total solid content in the resin composition (1). More preferably, it is 0.1 to 7% by mass.

The hydrophobic resin (D), like the resin (A), naturally has few impurities such as metals, and the residual monomer or oligomer component is preferably 0.01 to 5% by mass, more preferably Is more preferably 0.01 to 3% by mass and 0.05 to 1% by mass. Thereby, the resin composition (1) which does not change over time, such as a foreign substance in liquid and sensitivity, is obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably 1 to 3, and still more preferably from the viewpoints of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is in the range of 1-2.

As the hydrophobic resin (D), various commercially available products can be used, and the hydrophobic resin (D) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable.
The reaction solvent, the polymerization initiator, the reaction conditions (temperature, concentration, etc.) and the purification method after the reaction are the same as those described for the resin (A), but in the synthesis of the hydrophobic resin (D), The concentration of the reaction is preferably 30 to 50% by mass. For more details, refer to the description in the vicinity of paragraphs 0320 to 0329 in JP-A-2008-292975.

Specific examples of the hydrophobic resin (D) are shown below. The following table shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), the weight average molecular weight, and the degree of dispersion.

[5] Basic compound The resin composition (1) preferably contains a basic compound.

(1) In one form, the resin composition (1) has a basic compound or an ammonium salt compound (hereinafter, referred to as “compound (N)”) whose basicity is reduced by irradiation with actinic rays or radiation. It is preferable to contain.
The compound (N) is preferably a compound (N-1) having a basic functional group or an ammonium group and a group capable of generating an acidic functional group upon irradiation with actinic rays or radiation. That is, the compound (N) is a basic compound having a basic functional group and a group capable of generating an acidic functional group upon irradiation with actinic light or radiation, or an acidic functional group upon irradiation with an ammonium group and active light or radiation. An ammonium salt compound having a group to be generated is preferable.
Specific examples of the compound (N) include the following compounds. In addition to the compounds listed below, examples of the compound (N) include the compounds (A-1) to (A-44) described in US Patent Application Publication No. 2010/0233629, and US patent applications. The compounds (A-1) to (A-23) described in JP 2012/0156617 A can also be preferably used in the present invention.

These compounds can be synthesized according to the synthesis examples described in JP-A-2006-330098.
The molecular weight of the compound (N) is preferably 500 to 1,000.
The resin composition (1) may or may not contain the compound (N), but when it is contained, the content of the compound (N) is based on the solid content of the resin composition (1). 0.1 to 20% by mass is preferable, and 0.1 to 10% by mass is more preferable.

(2) In another embodiment, the resin composition (1) is a basic compound (N) different from the compound (N) as a basic compound in order to reduce a change in performance over time from exposure to heating. ') May be included.
Preferred examples of the basic compound (N ′) include compounds having structures represented by the following formulas (A ′) to (E ′).

In general formulas (A ′) and (E ′):
RA ²⁰⁰ , RA ²⁰¹ and RA ²⁰² may be the same or different and are a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 20), a cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (having a carbon number of 6 to 20), and RA ²⁰¹ and RA ²⁰² may be bonded to each other to form a ring. RA ²⁰³ , RA ²⁰⁴ , RA ²⁰⁵ and RA ²⁰⁶ may be the same or different and each represents an alkyl group (preferably having 1 to 20 carbon atoms).
The alkyl group may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and a carbon group having 1 to 20 carbon atoms. A cyanoalkyl group is preferred.
The alkyl groups in the general formulas (A ′) and (E ′) are more preferably unsubstituted.
Specific examples of the basic compound (N ′) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine, and more preferable specific examples include an imidazole structure. , Diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure compound, alkylamine derivative having hydroxyl group and / or ether bond, aniline derivative having hydroxyl group and / or ether bond Etc.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, 1,8-diazabicyclo [5,4, 0] Undecaker 7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) Examples include sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, 2-oxopropylthiophenium hydroxide, and the like. Examples of the compound having an onium carboxylate structure are compounds in which the anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the compound having an aniline structure include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.
Preferred examples of the basic compound further 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. Specific examples thereof include, but are not limited to, compounds (C1-1) to (C3-3) exemplified in [0066] of US Patent Application Publication No. 2007/0224539. Absent.

The resin composition (1) may or may not contain the compound (N ′), but when it is contained, the content of the compound (N ′) is determined based on the solid content of the resin composition (1). The reference is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass.

(3) In another embodiment, the resin composition (1) is a nitrogen-containing organic compound having a group capable of leaving by the action of an acid (hereinafter referred to as “basic compound (N ″)) as one type of basic compound. May also be included. As an example of this compound, for example, specific examples of the compound are shown below.

The above compound can be synthesized, for example, according to the method described in JP-A-2009-199021.
As the basic compound (N ″), a compound having an amine oxide structure can also be used. Specific examples of this compound include triethylamine pyridine N-oxide, tributylamine N-oxide, triethanolamine N-oxide, tris (methoxyethyl) amine N-oxide, tris (2- (methoxymethoxy) ethyl) amine = oxide. 2,2 ′, 2 ″ -nitrilotriethylpropionate N-oxide, N-2- (2-methoxyethoxy) methoxyethylmorpholine N-oxide, and other amine oxide compounds exemplified in JP-A-2008-102383 are used. Is possible.

The molecular weight of the basic compound (N ″) is preferably 250 to 2000, and more preferably 400 to 1000. From the viewpoint of further reduction in LWR and uniformity of local pattern dimensions, the molecular weight of the basic compound is preferably 400 or more, more preferably 500 or more, and even more preferably 600 or more. .
These basic compounds (N ″) may be used in combination with the compound (N), or are used alone or in combination of two or more.
The resin composition (1) in the present invention may or may not contain the basic compound (N ″), but when it is contained, the amount of the basic compound (N ″) used is the resin composition. Based on the solid content of (1), it is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass.

(4) In another form, the resin composition (1) may contain an onium salt represented by the following general formula (6A) or (6B) as a basic compound. This onium salt is expected to control the diffusion of the generated acid in the resist system in relation to the acid strength of the photoacid generator usually used in the resist composition.

In general formula (6A),
Ra represents an organic group. However, those in which a fluorine atom is substituted for a carbon atom directly bonded to a carboxylic acid group in the formula are excluded.
X ⁺ represents an onium cation.
In general formula (6B),
Rb represents an organic group. However, those in which a fluorine atom is substituted for a carbon atom directly bonded to the sulfonic acid group in the formula are excluded.
X ⁺ represents an onium cation.

In the organic group represented by Ra and Rb, the atom directly bonded to the carboxylic acid group or sulfonic acid group in the formula is preferably a carbon atom. However, in this case, in order to make the acid relatively weaker than the acid generated from the above-mentioned photoacid generator, the fluorine atom does not substitute for the carbon atom directly bonded to the sulfonic acid group or carboxylic acid group.
Examples of the organic group represented by Ra and Rb include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an aralkyl group having 7 to 30 carbon atoms. Alternatively, a heterocyclic group having 3 to 30 carbon atoms can be used. In these groups, some or all of the hydrogen atoms may be substituted.

Examples of the substituent that the alkyl group, cycloalkyl group, aryl group, aralkyl group and heterocyclic group may have include a hydroxyl group, a halogen atom, an alkoxy group, a lactone group, and an alkylcarbonyl group.

Examples of the onium cation represented by X ⁺ in the general formulas (6A) and (6B) include a sulfonium cation, an ammonium cation, an iodonium cation, a phosphonium cation, and a diazonium cation. Among these, a sulfonium cation is more preferable.
As the sulfonium cation, for example, an arylsulfonium cation having at least one aryl group is preferable, and a triarylsulfonium cation is more preferable. The aryl group may have a substituent, and the aryl group is preferably a phenyl group.
As an example of a sulfonium cation and an iodonium cation, the structure demonstrated in the compound (B) can also be mentioned preferably.
A specific structure of the onium salt represented by the general formula (6A) or (6B) is shown below.

The resin composition (1) may or may not contain the onium salt, but when it is contained, the content of the onium salt is 0 based on the solid content of the resin composition (1). 0.001 to 20% by mass is preferable, and 0.01 to 10% by mass is more preferable.

(5) In another form, the resin composition (1) is a compound included in the formula (I) of JP2012-189977A, and the formula (I) of JP2013-6827A as a basic compound. In a molecule such as a compound represented by formula (I) in JP2013-8020A, a compound represented by formula (I) in JP2012-252124A, and the like. A compound having both an onium salt structure and an acid anion structure (hereinafter also referred to as a betaine compound) may be contained. Examples of the onium salt structure include a sulfonium, iodonium, and ammonium structure, and a sulfonium or iodonium salt structure is preferable. The acid anion structure is preferably a sulfonate anion or a carboxylic acid anion. Examples of this compound include the following.

The resin composition (1) may or may not contain the betaine compound, but when it is contained, the content of the betaine compound is 0 based on the solid content of the resin composition (1). 0.001 to 20% by mass is preferable, and 0.01 to 10% by mass is more preferable.

[6] Surfactant The resin composition (1) may further contain a surfactant. When the resin composition (1) contains a surfactant, fluorine and / or silicon surfactant (fluorine surfactant, silicon surfactant, surfactant having both fluorine atom and silicon atom) It is more preferable to contain any one of these or 2 or more types.
When the resin composition (1) contains a surfactant, it is possible to provide a resist pattern with less adhesion and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes.

Examples of the fluorine-based and / or silicon-based surfactant include surfactants described in [0276] of US Patent Application Publication No. 2008/0248425. For example, Fluorard FC430, 431, 4430 (Sumitomo 3M) ), Megafuck Series (manufactured by DIC Corporation), Surflon S-382, SC101, 102, 103, 104, 105, 106, KH-20 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical ( GF-300, GF-150 (manufactured by Toagosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351 , EF352, EF801, EF802, EF601 (Co., Ltd.) Made mucopolysaccharides), PF636, PF656, PF6320, PF6520, and the like (manufactured by OMNOVA Inc.), FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D, 222D ((Ltd.) Neos). Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As surfactants corresponding to the above, Megafac F178, F-470, F-473, F-475, F-476, F-472 (manufactured by DIC Corporation), acrylates having C ₆ F ₁₃ groups (or methacrylate) and (poly (oxyalkylene)) acrylate (copolymer of or methacrylate), and acrylate having a C ₃ F ₇ group (or methacrylate) (poly (oxyethylene) and) acrylate (or methacrylate) (poly ( And a copolymer with oxypropylene)) acrylate (or methacrylate).

In the present invention, surfactants other than the fluorine-based and / or silicon-based surfactants described in [0280] of US Patent Application Publication No. 2008/0248425 may also be used.

These surfactants may be used alone or in some combination.

When the resin composition (1) contains a surfactant, the amount of the surfactant used is preferably 0.0001 to 2% by mass based on the total amount of the resin composition (1) (excluding the solvent), More preferably, it is 0.0005 to 1% by mass.
On the other hand, by making the addition amount of the surfactant 10 ppm or less with respect to the total amount of the resin composition (1) (excluding the solvent), the surface unevenness of the hydrophobic resin is increased. Can be made more hydrophobic, and the water followability during immersion exposure can be improved.

[7] Other additives (G)
The resin composition (1) may contain a carboxylic acid onium salt. Examples of such carboxylic acid onium salts include those described in US Patent Application Publication No. 2008/0187860 [0605] to [0606].
When the resin composition (1) contains a carboxylic acid onium salt, the content is generally 0.1 to 20% by mass, preferably 0.8%, based on the total solid content of the resin composition (1). 5 to 10% by mass, more preferably 1 to 7% by mass.

Moreover, the resin composition (1) may contain a so-called acid proliferating agent as necessary. The acid proliferating agent is particularly preferably used when performing the pattern forming method of the present invention by EUV exposure or electron beam irradiation. Although it does not specifically limit as a specific example of an acid multiplication agent, For example, the following is mentioned.

If necessary, the resin composition (1) may further include 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 (for example, a molecular weight of 1000 The following phenol compounds, alicyclic or aliphatic compounds having a carboxyl group, and the like can be contained.

<Actinic ray-sensitive or radiation-sensitive resin composition (2)>
Next, the actinic ray-sensitive or radiation-sensitive resin composition (2) (also simply referred to as “resin composition (2)”) used in the pattern forming method of the present invention will be described.
The resin composition (2) can similarly contain the above-described components that the resin composition (1) can contain, and the preferred range of the content of each component relative to the total amount of the resin composition (2) is also This is the same as that described in the resin composition (1).

The solid content concentration of the resin compositions (1) and (2) is usually 1.0 to 30.0% by mass, preferably 1.5 to 30.0% by mass, more preferably 2.0 to 30%. 0.0% by mass. In particular, when a light source having a wavelength of 1 to 200 nm (specifically, an ArF excimer laser described later) is used, the solid content concentrations of the resin compositions (1) and (2) are 1.0 to 12. The content is preferably 0% by mass, and more preferably 2.0 to 9.0% by mass.
When a light source having a wavelength of more than 200 nm and not more than 250 nm (specifically, a KrF excimer laser described later) is used, the solid content concentration of the resin compositions (1) and (2) is 6.0 to 30. It is preferably 0.0% by mass, more preferably 9.0 to 25.0% by mass, and still more preferably 9.0 to 25.0% by mass. By setting the solid content concentration within the above range, the resist solution can be uniformly applied on the substrate.
The solid content concentration is a mass percentage of the mass of other resist components excluding the solvent with respect to the total mass of the actinic ray-sensitive or radiation-sensitive resin composition.

Resin compositions (1) and (2) are used by dissolving the above components in a predetermined organic solvent, preferably the above mixed solvent, filtering the solution, and applying the solution on a predetermined support (substrate). The pore size of the filter used for filter filtration is preferably 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less made of polytetrafluoroethylene, polyethylene, or nylon. In filter filtration, for example, as in JP-A-2002-62667, circulation filtration may be performed, or filtration may be performed by connecting a plurality of types of filters in series or in parallel. Moreover, you may filter resin composition (1) and (2) in multiple times. Furthermore, you may perform a deaeration process etc. with respect to resin composition (1) and (2) before and after filter filtration.

The resin composition (1) and the resin composition (2) may be the same as or different from each other. When the exposure light source in the step (v) and the exposure light source in the step (i-2) are the same, the resin composition (1) and the resin composition (2) are preferably the same.
It should be noted that the intermix between the two is considered to be less likely to cause a problem when the first pattern is formed in step (i-3) and then thermosetting (heating) is performed as in the heating step (ii). However, this does not preclude resist design in consideration of intermix problems.
In order to suppress the intermix, for example, as a solvent contained in the resin composition (2), a solvent that dissolves the resin of the resin composition (2) but does not dissolve the resin of the resin composition (1). It is possible to choose. For such a design, for example, the solvent contained in the resin composition (2) includes the solvents mentioned above as the rinse liquid containing an organic solvent. Preferable examples can be given.

As described above, in the pattern formation method of the invention, at least one of the actinic ray-sensitive or radiation-sensitive resin compositions (1) and (2) contains a resin containing a repeating unit having Si atoms.
It is preferable that the actinic ray-sensitive or radiation-sensitive resin composition (2) contains a resin containing a repeating unit having an Si atom because it is more excellent in reducing defects.
In addition, because of its excellent pattern shape, both the actinic ray-sensitive or radiation-sensitive resin composition (1) and the actinic ray-sensitive or radiation-sensitive resin composition (2) contain repeating units having Si atoms. It is preferable that resin is included. When both the actinic ray-sensitive or radiation-sensitive resin composition (1) and the actinic ray-sensitive or radiation-sensitive resin composition (2) contain a repeating unit having an Si atom, the actinic ray-sensitive or radiation-sensitive property The Si atom content in the resin in the resin composition (1) is preferably smaller than the Si atom content in the resin in the actinic ray-sensitive or radiation-sensitive resin composition (2).

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

<Preparation of actinic ray-sensitive or radiation-sensitive resin composition>
The components shown in Table 4 below were dissolved by 8.0% by mass in the total solid content with the solvents shown in the same table, and each was filtered through a polyethylene filter having a pore size of 0.1 μm, and actinic ray sensitive or radiation sensitive. Resin compositions PR-1 to 32 were prepared.

<Resin>
Resins in Table 4 are as shown in the following structural formulas and Table 5.
The resin was synthesized as follows.
(Synthesis Example (Synthesis of Resin A-1))
Under a nitrogen stream, 60.7 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. While stirring this liquid, the monomers corresponding to the repeating units of the following structural formula and resin A-1 shown in Table 5 were sequentially added from the left in the order of 5.23 g, 20.61 g, 4.77 g, polymerization initiator V- A solution prepared by dissolving 601 (manufactured by Wako Pure Chemical Industries, 0.506 g) in 112.7 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further continued at 80 ° C. for 2 hours. The reaction solution is allowed to cool and then added dropwise over a period of 20 minutes to a mixed solution of 1286 g of methanol / 143 g of water. The precipitated powder is collected by filtration and dried to yield the following resin A-1 (18.6 g), which is an acid-decomposable resin. Obtained. The composition ratio (molar ratio) of the repeating units determined from the NMR (nuclear magnetic resonance) method was 5/75/20. The obtained resin A-1 had a weight average molecular weight of 20000 in terms of standard polystyrene and a dispersity (Mw / Mn) of 1.7.
(Synthesis Example (Synthesis of Resins A-2 to 32))
Resins A-2 to 32 were synthesized in the same manner as the synthesis of Resin A-1, except that in the synthesis of Resin A-1, the monomers used and the amounts used were changed. Hereinafter, the composition ratio (molar ratio; corresponding in order from the left), weight average molecular weight (Mw), and dispersity (Mw / Mn) of the repeating units in resins A-2 to A32 are shown below. In the following structures, TMS, TES, Et, and iBu represent a trimethylsilyl group, a triethylsilyl group, an ethyl group, and an isobutyl group, respectively.

The acid generators in Table 4 above are as follows.

<Basic compound>
The basic compounds in Table 4 are as follows.

<Hydrophobic resin>
The additives (hydrophobic resins) in Table 4 are as follows.

<Surfactant>
The surfactants in Table 4 are as follows.
W-1: Megafuck F176 (manufactured by DIC Corporation; fluorine-based)
W-2: Megafuck R08 (manufactured by DIC; fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd .; silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: KH-20 (Asahi Glass Co., Ltd.)
W-6: PolyFox PF-6320 (manufactured by OMNOVA Solutions Inc .; fluorine system)

<Solvent>
The solvents in Table 4 are as follows.
SL-1: Propylene glycol monomethyl ether acetate (PGMEA)
SL-2: Ethyl lactate SL-3: Propylene glycol monomethyl ether (PGME)
SL-4: cyclohexanone SL-5: γ-butyrolactone SL-6: 4-methyl-2-pentanol SL-7: 2-ethylbutanol

<Pattern Forming Method: Examples 1 to 25 and Comparative Example>
(Formation of first film)
First, ARC29SR (Nissan Chemical Co., Ltd.) for antireflection film was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resin composition (1) shown in Table 6 below was applied thereon, and a first heating (PB1) was performed at 100 ° C. for 60 seconds to form a first film having a thickness of 270 nm. In Example 25, the following resin (topcoat resin) was 2.5% by mass, the polyethylene glycol compound shown below was 0.5% by mass, and 4-methyl-2-pentanol solvent was 7% by mass. A top coat layer having a thickness of 100 nm was formed on the resist film (first film) using a top coat composition containing 90% by mass of 1-butanol solvent.

Topcoat resin and polyethylene glycol compound structure

(First negative pattern formation)
An ArF excimer laser scanner (PAS5500 / 1100, manufactured by ASML, NA0.75, Annular, σout / in 0.89 / 0.65) is used for the first film, and the first mask (6% halftone hole pattern) , Pattern pitch: 240 nm, critical dimension: 120 nm). Next, the second heating (PEB1) was performed at 110 ° C. for 60 seconds. Next, organic solvent development was carried out using butyl acetate to obtain a first negative pattern (80 nm hole pattern). This is schematically represented by the state shown in FIG.

(Heating for forming the first negative pattern)
The first negative pattern obtained as described above was subjected to third heating (Post Bake 1) at 200 ° C. for 60 seconds. This is schematically represented by the state shown in FIG.

(Formation of second film)
The resin composition (2) shown in Table 6 below is applied on the substrate on which the first negative pattern is formed, and the fourth heating (PB2) is performed at 100 ° C. for 60 seconds, and the film thickness is 270 nm. A second film was formed. This is schematically represented by the state shown in FIG. In Example 25, the same topcoat layer as that provided on the first film was also provided on the second film.

(Second negative pattern formation)
An ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Annular, σout / in 0.89 / 0.65, manufactured by ASML) was used for the second film, and the second mask (6% halftone line and Pattern exposure (second exposure) was performed via a space pattern, a pattern pitch: 240 nm, and a critical dimension: 120 nm. Next, the fifth heating (PEB2) was performed at 105 ° C. for 60 seconds. Next, organic solvent development was performed using butyl acetate to obtain a second negative pattern (line and space pattern having a line of 80 nm). This is schematically represented by the state shown in FIG.
The second negative pattern obtained as described above was subjected to sixth heating (Post Bake 2) at 90 ° C. for 60 seconds.

<Evaluation>
[Pattern shape]
The cross-sectional shape of the obtained pattern was observed with a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.), and each of the shape of the upper layer pattern and the shape of the lower layer pattern was evaluated by “rectangle” or “tailing”. The results are shown in Table 6. Practically, the pattern shape is preferably “rectangular”.

(Defect assessment)
After the above-described resist pattern is formed, defect coordinate data is obtained using a defect evaluation apparatus (KLA 2360, manufactured by KLA), and an electron microscope image of each coordinate is used using a defect review apparatus (SEMVision G3, manufactured by Applied Materials). , The number of residual defects after development on an 8-inch Si wafer (Si wafer having a diameter of 200 mm) was counted. The results are shown in Table 6 (residue defects). In practice, in order to achieve a high yield, the number of residual defects is preferably 50 or less, more preferably 10 or less, and even more preferably 5 or less.

As can be seen from Table 6 above, Examples 1 to 25 using a resin containing Si showed an effect of reducing residual defects as compared with Comparative Examples using a resin containing no Si. In particular, in Examples 1 to 20 in which a resin containing Si was used for forming the second pattern, a remarkable effect of reducing residual defects was observed. In particular, in Examples 1 to 13 using a resin containing Si having a cage silsesquioxane structure as the resin composition (2), a further effect of reducing defects was observed. This is because a resin containing Si, particularly a resin containing Si having a silsesquioxane structure, has higher solubility in an organic developer than a resin containing no Si, and development without leaving a residue. It is thought that this is because of progress.
Moreover, in the pattern shape, the shape of the layer formed by patterning using the resin containing Si was rectangular. This is presumably because the resin containing Si has high solubility in an organic developer, and therefore it is possible to suppress deterioration of the pattern shape such as tailing due to the resin dissolution residue.

Although the embodiments have been described above, the present invention is not limited to these embodiments. For example, it is considered that a pattern can be formed in the following manner.
For example, in each embodiment, an embodiment in which the exposure with ArF excimer laser is replaced with ArF excimer laser immersion exposure or KrF excimer laser exposure, and further, an embodiment in which organic solvent development is replaced with alkali development.

10: Substrate 51, 52: First pattern 60: Second film 61: Second pattern

Claims

(I) a step of forming the first pattern on the substrate by performing the following step (i-1), the following step (i-2) and the following step (i-3) in this order;
(I-1) a step of forming a first film on the substrate using the actinic ray-sensitive or radiation-sensitive resin composition (1) (i-2) a step of exposing the first film i-3) Step of developing the exposed first film using a developer to form the first pattern (iii) Actinic ray sensitive or radiation sensitive at least on the first pattern Forming a second film using the resin composition (2);
(V) exposing the second film; and
(Vi) developing the exposed second film using a developer to form a second pattern on at least the first pattern;
A pattern forming method comprising:
A pattern in which at least one of the actinic ray-sensitive or radiation-sensitive resin compositions (1) and (2) is an actinic ray-sensitive or radiation-sensitive resin composition containing a resin containing a repeating unit having a Si atom. Forming method.
The pattern forming method according to claim 1, wherein the content of the resin including a repeating unit having an Si atom is 10% by mass or more based on the total solid content in the actinic ray-sensitive or radiation-sensitive resin composition. .
3. The pattern forming method according to claim 1, wherein the content of Si atoms in the resin containing the repeating unit having Si atoms is 1.0 to 30% by mass.
The pattern forming method according to any one of claims 1 to 3, wherein the resin containing a repeating unit having an Si atom has an acid-decomposable group.
5. The pattern forming method according to claim 1, wherein the repeating unit having a Si atom has a silsesquioxane structure.
The pattern formation method according to claim 5, wherein the silsesquioxane structure is a cage-type silsesquioxane structure.
7. The pattern forming method according to claim 1, wherein the resin containing a repeating unit having an Si atom contains a repeating unit having at least one of a lactone structure, a sultone structure, and a carbonate structure.
The pattern forming method according to any one of claims 1 to 7, wherein the developer used in the step (i-3) is a developer containing an organic solvent.
The pattern forming method according to any one of claims 1 to 8, wherein the developer used in the step (vi) is a developer containing an organic solvent.
The actinic ray-sensitive or radiation-sensitive resin composition (1) contains a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases. 2. The pattern forming method according to claim 1.
The actinic ray-sensitive or radiation-sensitive resin composition (2) contains a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases. 2. The pattern forming method according to claim 1.
The pattern forming method according to any one of claims 1 to 11, further comprising a heating step (ii) between the step (i) and the step (iii).
The pattern forming method according to any one of claims 1 to 12, further comprising a heating step after the step (vi).
The pattern forming method according to any one of claims 1 to 13, wherein the actinic ray-sensitive or radiation-sensitive resin composition (2) contains a resin containing a repeating unit having an Si atom.
The pattern forming method according to any one of claims 1 to 14, wherein the actinic ray-sensitive or radiation-sensitive resin composition (1) contains a resin containing a repeating unit having a Si atom.
The actinic ray sensitive or radiation sensitive resin composition (1) and the actinic ray sensitive or radiation sensitive resin composition (2) are different from each other. Pattern forming method.
The actinic ray-sensitive or radiation-sensitive resin composition (1) and the actinic ray-sensitive or radiation-sensitive resin composition (2) are the same as defined in any one of claims 1 to 15. Pattern forming method.
An etching method for performing an etching process on the substrate using a pattern formed by the pattern forming method according to any one of claims 1 to 17 as a mask.
An electronic device manufacturing method comprising the pattern forming method according to any one of claims 1 to 18.