JP5724265B2 - Radiation sensitive resin composition, resist pattern forming method, and polymer - Google Patents

Description

  The present invention relates to a chemically amplified resist, particularly a radiation-sensitive resin composition that can be suitably used as a resist for immersion exposure, a resist pattern forming method using the composition, and fluorine as a constituent component of the composition. It relates to the polymer to be contained.

  In the field of microfabrication represented by the manufacture of integrated circuit elements, a resist film is formed on a substrate with a resin composition containing a polymer having an acid-dissociable group, and the resist film has a short wavelength via a mask pattern. A fine resist pattern is formed by irradiating with radiation (excimer laser or the like) and exposing, and removing the exposed portion by alkali development. At this time, a “chemically amplified resist” is used in which a radiation-sensitive acid generator that generates an acid upon irradiation with radiation is contained in the resin composition, and the sensitivity is improved by the action of the acid.

  In addition, as a method for forming a finer resist pattern (for example, a line width of about 45 nm), the use of “immersion exposure (liquid immersion lithography)” is expanding. In this method, the exposure optical path space (between the lens and the resist film) is immersed in an immersion exposure liquid (for example, pure water or a fluorine-based inert liquid) having a refractive index (n) larger than that of air or an inert gas. Exposure is performed in the satisfied state. Therefore, even when the numerical aperture (NA) of the lens is increased, there is an advantage that the depth of focus is hardly lowered and high resolution can be obtained.

  The resin composition used in the immersion exposure method has hydrophobicity for the purpose of preventing elution of an acid generator and the like from the resist film to the immersion exposure liquid and improving drainage of the resist film. A resin composition containing a high fluorine-containing polymer has been proposed (see Patent Document 1).

  Furthermore, for the purpose of suppressing development defects and the like in the unexposed areas associated with the hydrophobization of the resist film, a fluorine-containing polymer that is hydrophobic during immersion exposure and hydrophilic during alkali development, specifically, phenol. A fluorine-containing polymer in which a highly hydrophobic fluoroacyl group is introduced into a functional hydroxyl group has also been proposed (see Patent Documents 2 and 3).

International Publication No. 2007 / 116664A JP 2009-132843 A JP 2009-139909 A

  The fluorine-containing polymers shown in Patent Documents 2 and 3 exhibit hydrophobicity due to the fluoroacyl group during immersion exposure, while the fluoroacyl group is removed during alkali development to exhibit hydrophilicity due to the phenolic hydroxyl group. . Therefore, the effect of suppressing development defects in the unexposed areas can be expected.

  However, the fluorine-containing polymers as shown in Patent Documents 2 and 3 exhibit a certain degree of effect of suppressing development defects in the unexposed portions, but the occurrence of scum during development and the pattern shape after development are round-top shapes. There were problems such as becoming.

The present invention has been made in order to solve the problems of the prior art as described above, and can improve the hydrophilicity during alkali development while ensuring the hydrophobicity during immersion exposure. In addition to being able to suppress development defects, a radiation-sensitive resin composition capable of providing a resist coating film having an excellent pattern shape after development, a resist pattern forming method using the composition, and the composition The present invention provides a fluorine-containing polymer as a constituent component.

  As a result of intensive studies to solve the problems of the prior art as described above, the present inventors have found that hydrophilic groups (alcoholic hydroxyl groups, amino groups, carboxyl groups, etc.) other than phenolic hydroxyl groups of the polymer are alkali-dissociated. It has been found that the above problem can be solved by using a fluorine-containing polymer modified with a functional group as a constituent of the radiation-sensitive resin composition, and the present invention has been completed. Specifically, the present invention provides the following radiation-sensitive resin composition, resist pattern forming method and fluorine-containing polymer.

［一般式（ｘ）中、Ｒ^１はアルカリ解離性基、Ａは酸素原子（但し、芳香環、カルボニル基及びスルホキシル基に直結するものを除く。）、イミノ基、−ＣＯ−Ｏ−＊又は−ＳＯ_２−Ｏ−＊（「＊」はＲ^１に結合する結合手を示す。）を示す。］ [1] A polymer (A) having an acid dissociable group and a fluorine atom content of less than 5% by mass, an acid generator (B) that generates an acid upon irradiation with radiation, and the following general formula (x) A radiation-sensitive resin composition comprising a polymer (C) having a functional group-containing fluorine atom content of 5% by mass or more.

[In general formula (x), R ¹ is an alkali-dissociable group, A is an oxygen atom (excluding those directly connected to an aromatic ring, a carbonyl group and a sulfoxyl group), an imino group, —CO—O— * or —SO ₂ —O— * (“*” represents a bond bonded to R ¹ ). ]

［一般式（ｃ−１）中、Ｒ^１はアルカリ解離性基、Ａは酸素原子、イミノ基、−ＣＯ−Ｏ−＊又は−ＣＯ−Ｏ−＊又は−ＳＯ_２−Ｏ−＊（「＊」はＲ^１に結合する結合手を示す。）、Ｒ^２は単結合、メチレン基、炭素数２〜１０の直鎖状若しくは分岐状のアルキレン基又は炭素数４〜２０の環状炭化水素基、Ｘ^１は単結合、ジフルオロメチレン基又は炭素数２〜２０の直鎖状若しくは分岐状のパーフルオロアルキレン基を示す。Ｒ^３は炭素数が１〜２０の（ｎ＋１）価の炭化水素基を示し、Ｒ^２側の末端に酸素原子、硫黄原子、イミノ基、カルボニル基、−ＣＯ−Ｏ−又は−ＣＯ−ＮＨ−が結合された構造のものも含む。Ｅは酸素原子、−ＣＯ−Ｏ−＊又は−ＣＯ−ＮＨ−＊（「＊」はＲ^３に結合する結合手を示す。）、Ｒは水素原子、メチル基又はトリフルオロメチル基、ｎは１〜３の整数を示す。但し、ｎが２又は３の場合、Ｒ^１、Ｒ^２、Ｘ^１及びＡは相互に独立である。］ [2] The radiation sensitive resin composition according to [1], wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1).

[In General Formula (c-1), R ¹ is an alkali-dissociable group, A is an oxygen atom, an imino group, —CO—O— *, —CO—O— *, or —SO ₂ —O— * (“* "Represents a bond bonded to R ^1. ), R ² represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a cyclic hydrocarbon group having 4 to 20 carbon atoms, X ¹ represents a single bond, a difluoromethylene group or a linear or branched perfluoroalkylene group having 2 to 20 carbon atoms. R ³ represents an (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH— at the terminal on the R ² side. Also includes a structure in which is bound. E is an oxygen atom, —CO—O— * or —CO—NH— * (“*” represents a bond bonded to R ³ ), R is a hydrogen atom, a methyl group or a trifluoromethyl group, and n is An integer of 1 to 3 is shown. However, when n is 2 or 3, R ¹ , R ² , X ¹ and A are independent of each other. ]

［一般式（ｃ−１ａ）中、Ｒ、Ｒ^１、Ｒ^２、Ｒ^３、Ｘ^１及びＡは一般式（ｃ−１）の説明と同義である。］ [3] The radiation sensitive resin composition according to [1], wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a).

[In the general formula (c-1a), R, R ¹ , R ² , R ³ , X ¹ and A are as defined in the general formula (c-1). ]

［一般式（ｃ−１ａ−１）中、Ｒ、Ｒ^２、Ｒ^３及びＸ^１は一般式（ｃ−１）の説明と同義である。Ｒ^８は少なくとも一の水素原子がフッ素原子に置換された、炭素数１〜１０のフッ素置換炭化水素基を示す。］ [4] The radiation sensitive resin composition according to [1], wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a-1).

[In the general formula (c-1a-1), R, R ² , R ³ and X ¹ have the same meanings as in the description of the general formula (c-1). R ⁸ represents a fluorine-substituted hydrocarbon group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. ]

［一般式（ｃ−１ａ−２）中、Ｒ、Ｒ^２及びＸ^１は一般式（ｃ−１）の説明と同義である。Ｒ^３１はメチレン基、炭素数２〜１０の直鎖状若しくは分岐状のアルキレン基又は炭素数４〜２０の２価の環状炭化水素基を示し、Ｒ^２側の末端に酸素原子、硫黄原子、イミノ基、カルボニル基、−ＣＯ−Ｏ−又は−ＣＯ−ＮＨ−が結合された構造のものも含む。Ｒ^９は下記式（１）〜（３）で表される基のうちいずれかを示す。］

［一般式（１）及び（２）中、Ｒ^１０はハロゲン原子又は炭素数１〜１０のアルキル基、アルコキシル基、アシル基若しくはアシロキシ基を示し、複数存在する場合は同一でも異なっていてもよい。ｍ１は０〜５の整数を示し、ｍ_２は０〜４の整数を示す。一般式（３）中、Ｒ^１１及びＲ^１２はそれぞれ独立に水素原子又は炭素数１〜１０のアルキル基を示し、Ｒ^１１及びＲ^１２が互いに結合して炭素数４〜２０の脂環式構造を形成してもよい。］ [5] The radiation sensitive resin composition according to [1], wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a-2).

[In the general formula (c-1a-2), R, R ² and X ¹ are as defined in the general formula (c-1). R ³¹ represents a methylene group, a divalent cyclic hydrocarbon group in the alkylene group or from 4 to 20 carbon atoms linear or branched having 2 to 10 carbon atoms, an oxygen atom at the terminal of R ² side, a sulfur atom, A structure in which an imino group, a carbonyl group, —CO—O— or —CO—NH— is bonded is also included. R ⁹ represents any one of groups represented by the following formulas (1) to (3). ]

[In the general formulas (1) and (2), R ¹⁰ represents a halogen atom or an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an acyl group, or an acyloxy group. . m1 represents an integer of 0 to 5, _{m 2} represents an integer of 0 to 4. In General Formula (3), R ¹¹ and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ¹¹ and R ¹² are bonded to each other to form an alicyclic structure having 4 to 20 carbon atoms. May be formed. ]

［一般式（ｃ−２）中、Ｒは一般式（ｃ−１）の説明と同義である。Ｇは単結合、酸素原子、硫黄原子、−ＣＯ−Ｏ−、−ＳＯ_２−Ｏ−ＮＨ−、−ＣＯ−ＮＨ−、−Ｏ−ＣＯ−ＮＨ−、Ｒ^４は少なくとも一の水素原子がフッ素原子に置換された、炭素数１〜６のフッ素置換鎖状炭化水素基又は少なくとも一の水素原子がフッ素原子に置換された、炭素数４〜２０のフッ素置換環状炭化水素基を示す。］

［一般式（ｃ−３）中、Ｒ及びＡは一般式（ｃ−１）の説明と同義である。Ｒ^７は水素原子又は酸解離性基、Ｒ^６は一般式（ｃ−１）のＲ^２と、Ｒ^５は一般式（ｃ−１）のＲ^３と、Ｘ^２は一般式（ｃ−１）のＸ^１と、各々同義である。ｍは１〜３の整数を示す。但し、ｍが２又は３の場合、Ｒ^６、Ｒ^７、Ｘ^２及びＡは相互に独立である。］ [6] The polymer [C] is a polymer further having a repeating unit represented by the following general formula (c-2) or a repeating unit represented by the following general formula (c-3) [1] ] The radiation sensitive resin composition in any one of [5].

[In general formula (c-2), R is synonymous with description of general formula (c-1). G is a single bond, oxygen atom, sulfur atom, —CO—O—, —SO ₂ —O—NH—, —CO—NH—, —O—CO—NH—, and R ⁴ is fluorine containing at least one hydrogen atom. A fluorine-substituted chain hydrocarbon group having 1 to 6 carbon atoms or a fluorine-substituted cyclic hydrocarbon group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. ]

[In general formula (c-3), R and A are synonymous with description of general formula (c-1). R ⁷ is a hydrogen atom or an acid-dissociable group, and ^{R 2} of ^{R 6} is the formula (c-1), and ^{R 3} of ^{R 5} of the general formula (c-1), ^{X 2} is Formula (c-1 ) And X ¹ . m shows the integer of 1-3. However, when m is 2 or 3, R ⁶ , R ⁷ , X ² and A are independent of each other. ]

[7] The radiation sensitive resin composition according to any one of [1] to [6], wherein 0.1 to 20 parts by mass of the polymer (C) is contained with respect to 100 parts by mass of the polymer (A). object.

[8] The radiation sensitive resin composition according to any one of [1] to [7], which is a radiation sensitive resin composition for immersion exposure.

[9] A film forming step (1) for forming a resist film made of the radiation-sensitive resin composition according to any one of [1] to [8] on a substrate, and the resist film through a mask pattern A resist pattern forming method comprising: an exposure step (2) in which the resist film is exposed to radiation, and a development step (3) in which the exposed resist film is developed to form a resist pattern.

[10] In the exposure step (2), an immersion exposure liquid is disposed on the resist film formed in the film formation step (1), and the resist film is exposed through the immersion exposure liquid. The resist pattern forming method according to [9].

［一般式（ｃ−１）中、Ｒ^１はアルカリ解離性基、Ａは酸素原子、イミノ基、−ＣＯ−Ｏ−＊又は−ＣＯ−Ｏ−＊又は−ＳＯ_２−Ｏ−＊（「＊」はＲ^１に結合する結合手を示す。）、Ｒ^２は単結合、メチレン基、炭素数２〜１０の直鎖状若しくは分岐状のアルキレン基又は炭素数４〜２０の環状炭化水素基、Ｘ^１は単結合、ジフルオロメチレン基又は炭素数２〜２０の直鎖状若しくは分岐状のパーフルオロアルキレン基を示す。Ｒ^３は炭素数が１〜２０の（ｎ＋１）価の炭化水素基を示し、Ｒ^２側の末端に酸素原子、硫黄原子、イミノ基、カルボニル基、−ＣＯ−Ｏ−又は−ＣＯ−ＮＨ−が結合された構造のものも含む。Ｅは酸素原子、−ＣＯ−Ｏ−＊又は−ＣＯ−ＮＨ−＊（「＊」はＲ^３に結合する結合手を示す。）、Ｒは水素原子、メチル基又はトリフルオロメチル基、ｎは１〜３の整数を示す。但し、ｎが２又は３の場合、Ｒ^１、Ｒ^２、Ｘ^１及びＡは相互に独立である。］ [11] A polymer having a repeating unit represented by the following general formula (c-1).

[In General Formula (c-1), R ¹ is an alkali-dissociable group, A is an oxygen atom, an imino group, —CO—O— *, —CO—O— *, or —SO ₂ —O— * (“* "Represents a bond bonded to R ^1. ), R ² represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a cyclic hydrocarbon group having 4 to 20 carbon atoms, X ¹ represents a single bond, a difluoromethylene group or a linear or branched perfluoroalkylene group having 2 to 20 carbon atoms. R ³ represents an (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH— at the terminal on the R ² side. Also includes a structure in which is bound. E is an oxygen atom, —CO—O— * or —CO—NH— * (“*” represents a bond bonded to R ³ ), R is a hydrogen atom, a methyl group or a trifluoromethyl group, and n is An integer of 1 to 3 is shown. However, when n is 2 or 3, R ¹ , R ² , X ¹ and A are independent of each other. ]

  The radiation-sensitive resin composition, resist pattern forming method and polymer of the present invention can improve hydrophilicity during alkali development while ensuring hydrophobicity during immersion exposure, and develop unexposed areas. In addition to being able to suppress defects, a resist coating film having excellent pattern shape after development can be provided.

  Hereinafter, the radiation sensitive resin composition, the resist pattern forming method and the form for carrying out the polymer of the present invention will be specifically described. However, the present invention includes all embodiments provided with the invention-specific matters, and is not limited to only the embodiments described below.

In the following description, the same type of substituent is given the same reference numeral, and the description is omitted. In addition, the “hydrocarbon group” referred to in this specification includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

  The term “chain hydrocarbon group” means a hydrocarbon group composed of only a chain structure without a cyclic structure in the main chain, and includes both a linear hydrocarbon group and a branched hydrocarbon group. Shall be. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be constituted only by the structure of the alicyclic hydrocarbon, and a part thereof may include a chain structure. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

[1]: Polymer (C):
The polymer (C) is a fluorine-containing polymer having a functional group represented by the following general formula (x) (hereinafter sometimes referred to as “functional group (x)”).

  The radiation-sensitive resin composition containing the polymer (C) and the polymer (A) described later is formed on the surface of the resist film due to the oil repellency of the polymer (C) when the resist film is formed. There exists a tendency for the distribution of a polymer (C) to become high. That is, the polymer (A) is unevenly distributed in the coating surface layer. Therefore, it is not necessary to separately form an upper layer film for the purpose of blocking the photoresist film from the immersion medium, and can be suitably used for the immersion exposure method.

  Further, since the functional group (x) undergoes hydrolysis to dissociate the alkali-dissociable group to produce a polar group during alkali development, the water repellency on the resist coating surface can be lowered. Therefore, it is considered that development defects occurring in the resist film after alkali development can be suppressed. In addition, a photoresist film having an excellent pattern shape after development can be formed as compared with a case where a phenolic hydroxyl group is generated during alkali development.

[1-1] Functional group (x)
The polymer (C) has a functional group (x) represented by the following general formula (x).

一般式（ｘ）中、Ａは酸素原子（但し、芳香環、カルボニル基及びスルホキシル基に直結するものを除く。）、イミノ基、−ＣＯ−Ｏ−＊又は−ＳＯ_２−Ｏ−＊（「＊」はＲ^１に結合する結合手を示す。）である。即ち、官能基（ｘ）は水酸基、アミノ基、カルボキシル基又はスルホキシル基がアルカリ解離性基によって修飾されたものである。 Such a functional group (x) causes a reaction as shown below with an alkaline aqueous solution to generate a polar group.

In the general formula (x), A represents an oxygen atom (excluding those directly bonded to an aromatic ring, a carbonyl group and a sulfoxyl group), an imino group, —CO—O— * or —SO ₂ —O— * (“ “*” Represents a bond bonded to R ¹ ). That is, the functional group (x) is a group in which a hydroxyl group, amino group, carboxyl group or sulfoxyl group is modified with an alkali dissociable group.

In the general formula (x), R ¹ represents an alkali dissociable group. The “alkali dissociable group” refers to a group that substitutes a hydrogen atom in a polar functional group and dissociates in the presence of an alkali.

Such an alkali dissociable group is not particularly limited as long as it exhibits the above-mentioned properties. When A is an oxygen atom or an imino group in the general formula (x), the following general formula (R1-1) Can be mentioned.

In General Formula (R1-1), R ⁸ is a hydrocarbon group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom.

For example, R ⁸ is a linear or branched group in which all or part of the hydrogen atoms of an alkyl group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms are substituted with fluorine atoms Is preferred.

  Examples of the alkyl group include methyl group, ethyl group, 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2- Pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl Group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) Group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- (2-methylpentyl) group, 3- (3-methylpentyl) group and the like.

  Examples of the alicyclic hydrocarbon group include a cyclopentyl group, cyclopentylmethyl group, 1- (1-cyclopentylethyl) group, 1- (2-cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- ( 1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) group, 1- (2-cycloheptylethyl) group, 2- A norbornyl group etc. can be mentioned.

R ⁸ is more preferably a linear or branched perfluoroalkyl group in which all of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms, and particularly preferably a trifluoromethyl group.

  The functional group (x) can be formed by fluoroacylating an alcohol, amine, or carboxylic acid by a conventionally known method. For example, 1) condensation of an alcohol and a fluorocarboxylic acid in the presence of an acid for esterification, and 2) condensation of an alcohol and a fluorocarboxylic acid halide in the presence of a base for esterification. it can.

Moreover, in the said general formula (x), when A is -CO-O- *, what is represented by the following general formula (R1-2)-(R1-4) can be mentioned.

[In the general formulas (R1-2) and (R1-3), R ¹⁰ represents a halogen atom or an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an acyl group, or an acyloxy group. But it can be different. m ₁ represents an integer of 0 to 5, and m ₂ represents an integer of 0 to 4. In General Formula (R1-4), R ¹¹ and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ¹¹ and R ¹² are bonded to each other to form an alicyclic ring having 4 to 20 carbon atoms. A formula structure may be formed. ]

In general formulas (R1-2) and (R1-3), examples of the halogen atom represented by R ¹⁰ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, fluorine atoms are preferred.

In general formulas (R1-2) and (R1-3), examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹⁰ include a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, 1- Butyl group, 2-butyl group, 2- (2-methylpropyl) group, 1-pentyl group, 2-pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group , 2- (2-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3-hexyl group, 1- (2-methylpentyl) group, 1- ( 3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (2-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) group, 3- ( 2-methylpentyl) group, 3- (3-methylpentyl) group Etc.

In the general formulas (R1-2) and (R1-3), examples of the alkoxyl group having 1 to 10 carbon atoms represented by R ¹⁰ include a methoxy group, an ethoxy group, an n-butoxy group, a t-butoxy group, A propoxy group, an isopropoxy group, etc. are mentioned.

Examples of the acyl group having 1 to 10 carbon atoms represented by R ^{10 in the} general formulas (R1-2) and (R1-3) include an acetyl group, an ethylcarbonyl group, and a propylcarbonyl group.

In the general formulas (R1-2) and (R1-3), examples of the acyloxy group having 1 to 10 carbon atoms represented by R ¹⁰ include an acetoxy group, an ethylyloxy group, a butyryloxy group, a t-butyryloxy group, a t- An amylyloxy group, n-hexane carbonyloxy group, n-octane carbonyloxy group, etc. are mentioned.

In the general formula (R1-4), examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹¹ or R ¹² include the same groups as those described above for R ¹⁰ .

Examples of the alicyclic structure formed by R ¹¹ and R ¹² bonded to each other and the carbon atoms to which they are bonded include a cyclopentyl group, cyclopentylmethyl group, 1- (1-cyclopentylethyl) group, 1- (2- Cyclopentylethyl) group, cyclohexyl group, cyclohexylmethyl group, 1- (1-cyclohexylethyl) group, 1- (2-cyclohexylethyl group), cycloheptyl group, cycloheptylmethyl group, 1- (1-cycloheptylethyl) Group, 1- (2-cycloheptylethyl) group, 2-norbornyl group and the like.

  Specific examples of the compound represented by the general formula (R1-4) include methyl group, ethyl group, 1-propyl group, 2-propyl group, 1-butyl group, 2-butyl group, 1-pentyl group, 2- Pentyl group, 3-pentyl group, 1- (2-methylbutyl) group, 1- (3-methylbutyl) group, 2- (3-methylbutyl) group, neopentyl group, 1-hexyl group, 2-hexyl group, 3- Hexyl group, 1- (2-methylpentyl) group, 1- (3-methylpentyl) group, 1- (4-methylpentyl) group, 2- (3-methylpentyl) group, 2- (4-methylpentyl) ) Group, 3- (2-methylpentyl) group and the like. Among these, a methyl group, an ethyl group, a 1-propyl group, a 2-propyl group, a 1-butyl group, and a 2-butyl group are preferable.

[1-2]: Fluorine atom content ratio:
The fluorine atom content ratio in the polymer (C) is 5% by mass or more, preferably 5 to 50% by mass, more preferably 5 to 40% by mass when the entire fluorine-containing polymer is 100% by mass. is there. In addition, this fluorine atom content rate can be measured by ¹³ C-NMR. When the fluorine atom content ratio in the polymer (C) is within the above range, the water repellency of the resist coating film surface formed by the radiation sensitive resin composition containing the polymer (C) and the polymer (A) described later is included. It is not necessary to separately form an upper layer film during the immersion exposure.

[1-3]: Repeating unit (c-1)
Examples of the polymer (C) include those having a repeating unit represented by the following general formula (c-1) (hereinafter sometimes referred to as “repeating unit (c-1)”). The repeating unit (c-1) is a repeating unit having a structure in which the functional group (x) is bonded to the main chain via X ¹ , R ² , R ³ and E. In general formula (c-1), R is a hydrogen atom, a methyl group, or a trifluoromethyl group.

In General Formula (c-1), X ¹ is a single bond, a difluoromethylene group, or a linear or branched perfluoroalkylene group having 2 to 20 carbon atoms.

一般式（Ｘ−１）中、ｐは１〜４の整数を示す。Ｒｆは相互に独立にフッ素原子又は炭素数１〜１０のパーフルオロアルキル基を示す。 Examples of the X ^1, may include those represented by the following general formula (X-1).

In general formula (X-1), p shows the integer of 1-4. Rf represents a fluorine atom or a C1-C10 perfluoroalkyl group mutually independently.

Specific examples of the structure represented by the formula (X-1) include those represented by the following formulas (X-2) and (X-3).

In General Formula (c-1), R ³ is a single bond or a carbon number of 1 to 20 and is an (n + 1) -valent hydrocarbon group, and n is an integer of 1 to 3. Accordingly, 1 to 3 functional groups (x) are introduced into the repeating unit (c-1). When n is 2 or 3, R ¹ , R ² and A are independent of each other. That is, when n is 2 or 3, the plurality of functional groups (x) may have the same structure or different structures. When n is 2 or 3, a plurality of functional groups (x) may be bonded to the same carbon atom of R ² or may be bonded to different carbon atoms.

Examples of the chain structure R ³ include methane, ethane, propane, butane, 2-methylpropane, pentane, 2-methylbutane, 2,2-dimethylpropane, hexane, heptane, octane, nonane, decane, and the like. (N + 1) -valent hydrocarbon group having a structure in which (n + 1) hydrogen atoms are removed from 10 chain hydrocarbons.

Examples of the cyclic structure R ³ include cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ^2,6. ] (N + 1) -valent hydrocarbon group having a structure in which (n + 1) hydrogen atoms are removed from alicyclic hydrocarbon such as decane, tricyclo [3.3.1.1 ^3,7 ] decane; aromatic such as benzene and naphthalene (N + 1) -valent hydrocarbon group having a structure obtained by removing (n + 1) hydrogen atoms from the group hydrocarbon.

The structure in which an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH— is bonded to the R ² end of R ³ is represented by the following general formula, for example. Can be mentioned.

Among the groups represented by R ² in the general formula (c-1), examples of the divalent linear or branched saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms include, for example, a methyl group , Ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group And a divalent hydrocarbon group derived from a linear or branched alkyl group having 1 to 20 carbon atoms such as an octyl group, a nonyl group, and a decyl group.

Examples of the divalent cyclic saturated or unsaturated hydrocarbon group include groups derived from alicyclic hydrocarbons or aromatic hydrocarbons having 3 to 20 carbon atoms. Specific examples of the alicyclic hydrocarbon include cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, and tricyclo [5.2.1.0 ^{2. , 6} ] decane, tricyclo [3.3.1.1 ^3,7 ] decane, tetracyclo [6.2.1.1 ^3,6 . And cycloalkanes such as 0 ^2,7 ] dodecane. Specific examples of aromatic hydrocarbons include benzene and naphthalene.

In the general formula (c-1), as the hydrocarbon group represented by R ² , at least one hydrogen atom is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or an n-butyl group. , 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like, linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, hydroxyl group, cyano group, hydroxy having 1 to 10 carbon atoms It may be substituted by one or more of an alkyl group, a carboxyl group, an oxygen atom and the like.

[1-3-1] Repeating unit (c-1a)
In general formula (c-1), R is a hydrogen atom, a methyl group or a trifluoromethyl group, E is an oxygen atom, -CO-O- * or -CO-NH- * ("*" represents R ³ The bond to be combined is shown.) Among them, those in which E is —CO—O— * are preferable. That is, the polymer (C) is a repeating unit represented by the following general formula (c-1a) as the repeating unit (c-1) (hereinafter sometimes referred to as “repeating unit (c-1a)”). It is preferable that it is a polymer which has.

As such a repeating unit (c-1a), a repeating unit represented by the following general formula (c-1a-1) (hereinafter sometimes referred to as “repeating unit (c-1a-1)”). Alternatively, a repeating unit represented by the following formula (c-1a-2) (hereinafter may be referred to as “repeating unit (c-1a-2)”) can be given.

［一般式（ｃ−１ａ−１）中、Ｒ、Ｒ^２及びＸ^１は一般式（ｃ−１）の説明と同義である。Ｒ^３１はメチレン基、炭素数２〜１０の直鎖状若しくは分岐状のアルキレン基又は炭素数４〜２０の２価の環状炭化水素基を示し、Ｒ^２側の末端に酸素原子、硫黄原子、イミノ基、カルボニル基、−ＣＯ−Ｏ−又は−ＣＯ−ＮＨ−が結合された構造のものも含む。Ｒ^９は下記式（１）〜（３）で表される基のうちいずれかを示す。］

［一般式（１）及び（２）中、Ｒ^１０はハロゲン原子又は炭素数１〜１０のアルキル基、アルコキシル基、アシル基若しくはアシロキシ基を示し、複数存在する場合は同一でも異なっていてもよい。ｍ１は０〜５の整数を示し、ｍ_２は０〜４の整数を示す。一般式（３）中、Ｒ^１１及びＲ^１２はそれぞれ独立に水素原子又は炭素数１〜１０のアルキル基を示し、Ｒ^１１及びＲ^１２が互いに結合して炭素数４〜２０の脂環式構造を形成してもよい。］ [In the general formula (c-1a-1), R, R ² , R ³ and X ¹ have the same meanings as in the description of the general formula (c-1). R ⁸ has the same meaning as in the description of General Formula (R1-1). ]

[In the general formula (c-1a-1), R, R ² and X ¹ are as defined in the general formula (c-1). R ³¹ represents a methylene group, a divalent cyclic hydrocarbon group in the alkylene group or from 4 to 20 carbon atoms linear or branched having 2 to 10 carbon atoms, an oxygen atom at the terminal of R ² side, a sulfur atom, A structure in which an imino group, a carbonyl group, —CO—O— or —CO—NH— is bonded is also included. R ⁹ represents any one of groups represented by the following formulas (1) to (3). ]

[In the general formulas (1) and (2), R ¹⁰ represents a halogen atom or an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an acyl group, or an acyloxy group. . m1 represents an integer of 0 to 5, _{m 2} represents an integer of 0 to 4. In General Formula (3), R ¹¹ and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ¹¹ and R ¹² are bonded to each other to form an alicyclic structure having 4 to 20 carbon atoms. May be formed. ]

A specific example of R ^{31 has} the same meaning as n = 1 in the description of R ³ above.

[1-3-1-1] Repeating unit (c-1a-1):
Specific examples of the repeating unit (c-1a-1) include those represented by the following formulas (c-1a-1a) to (c-1a-1b).

In general formula (c-1a-1a) and general formula (c-1a-1b), R is synonymous with the description of general formula (c-1). R ⁸ has the same meaning as in the description of General Formula (R1-1). n1 represents an integer of 0 to 4 independently of each other. Rf each independently represents a fluorine atom or a C 1-10 perfluoroalkyl group, preferably a fluorine atom or a trifluoromethyl group. R ² has the same meaning as in the description of General Formula (c-1). R ³¹ has the same ^{definition as} in the general formula (c-1a-2). R ³² represents a linear or branched trivalent hydrocarbon group having 1 to 10 carbon atoms, or a trivalent cyclic hydrocarbon group having 4 to 20 carbon atoms, and an oxygen atom or sulfur at the terminal on the R ² side. You may have an atom, a carbonyl group, or an imino group. A specific example of R ^{32 has} the same meaning as that in which n = 2 in the description of R ³ above.

  In the general formulas (c-1a-1a) and (c-1a-1b), those having n1 of 1 or more generate an OH group having a fluorine atom or a perfluoroalkyl group at the α-position by reaction with an aqueous alkaline solution. . Such an OH group has a low pKa value as compared with an alcoholic OH group, and thus is preferable from the viewpoint of improving hydrophilicity.

Specific examples of the repeating unit represented by the above formula (c-1a-1a) include those represented by the following formulas (c-1a-1c) to (c-1a-1f). Specific examples of the repeating unit represented by the formula (c-1a-1b) include those represented by the following formulas (c-1a-1g) to (c-1a-1h). .

In the general formulas (c-1a-1f) to (c-1a-1g), R ⁸ has the same meaning as the description of the general formula (R1-1). R is synonymous with the description of the general formula (c-1).

[1-3-1-2] Repeating unit (c-1a-2):
Specific examples of the repeating unit (c-1a-2) include those represented by the following formulas (c-1a-2a) to (c-1a-2b).

In general formula (c-1a-2a) and general formula (c-1a-2b), R is synonymous with the description of general formula (c-1). R ⁹ is synonymous with the description of the general formula (c-1a-2). n2 represents an integer of 0 to 4 independently of each other. Rf each independently represents a fluorine atom or a C 1-10 perfluoroalkyl group, preferably a fluorine atom or a trifluoromethyl group. R ²¹ independently represents a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a divalent cyclic hydrocarbon group having 4 to 20 carbon atoms. R ²² represents a single bond or the same meaning as in the description of R ²¹ .

  In the general formula (c-1a-2a) and the general formula (c-1a-2b), those having n2 of 1 or more have a fluorine atom or a perfluoroalkyl group at the α-position of the carbonyloxy group, and an alkaline aqueous solution It is thought that the reactivity with respect to increases. Moreover, the pKa of the COOH group generated by hydrolysis of the alkali dissociable group is also low, which is preferable from the viewpoint of improving hydrophilicity.

Specific examples of the repeating unit represented by the general formula (c-1a-2a) include those represented by the following general formulas (c-1a-2e) to (c-1a-2f). . Specific examples of the repeating unit represented by the general formula (c-1a-2b) include those represented by the following general formulas (c-1a-2c) to (c-1a-2d). Can do.

[1-4]: Repeating unit (c-2)
The fluorine-containing polymer of the present invention is a polymer having a repeating unit (c-2) represented by the following general formula (c-2) in addition to the repeating unit (c-1). preferable.

In general formula (c-2), R is synonymous with the description of general formula (c-1). G is a single bond, oxygen atom, sulfur atom, —CO—O—, —SO ₂ —O—NH—, —CO—NH—, —O—CO—NH—, and R ⁴ is at least one hydrogen atom. Is a fluorine-substituted chain hydrocarbon group having 1 to 6 carbon atoms in which is substituted with a fluorine atom or a fluorine-substituted cyclic hydrocarbon group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom.

  Examples of the monomer that gives the repeating unit (c-2) include trifluoromethyl (meth) acrylic acid ester, 2,2,2-trifluoroethyl (meth) acrylic acid ester, and perfluoroethyl (meth) acrylic acid. Ester, perfluoro n-propyl (meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, Perfluoro t-butyl (meth) acrylic acid ester, 2- (1,1,1,3,3,3-hexafluoropropyl) (meth) acrylic acid ester, 1- (2,2,3,3,4 , 4,5,5-octafluoropentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl (meth) Acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, 1- (3,3,4,4,5,5,6,6,7,7 , 8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoromethyl-3,3,4,4,5,6,6, 6-octafluorohexyl) (meth) acrylic acid ester and the like.

[1-5]: Repeating unit (c-3)
Furthermore, the fluorine-containing polymer of the present invention is a polymer having a repeating unit (c-3) represented by the following general formula (c-3) in addition to the repeating unit (c-1). preferable.

In general formula (c-3), R and A are synonymous with description of general formula (c-1). R ⁶ has the same meaning as R ^{2 in} formula (c-1), R ⁵ has the same meaning as R ^{3 in} formula (c-1), and X ² has the same meaning as X ^{1 in} formula (c-1).

In general formula (c-3), R ⁷ is a hydrogen atom or an acid dissociable group. The “acid-dissociable group” refers to a group that substitutes a hydrogen atom in a polar functional group such as a hydroxyl group or a carboxyl group and dissociates in the presence of an acid.

  Specifically, t-butoxycarbonyl group, tetrahydropyranyl group, tetrahydrofuranyl group, (thiotetrahydropyranylsulfanyl) methyl group, (thiotetrahydrofuranylsulfanyl) methyl group, alkoxy-substituted methyl group, alkylsulfanyl-substituted methyl group Etc. In addition, as an alkoxyl group (substituent) in an alkoxy substituted methyl group, there exists a C1-C4 alkoxyl group, for example. Examples of the alkyl group (substituent) in the alkylsulfanyl-substituted methyl group include an alkyl group having 1 to 4 carbon atoms. Moreover, as an acid dissociable group, group represented by general formula (i) described in the term of the repeating unit (c-4) mentioned later may be sufficient.

In general formula (c-3), m represents an integer of 1 to 3. Accordingly, 1 to 3 R ⁷ are introduced into the repeating unit (c-3). When n is 2 or 3, when m is 2 or 3, R ⁶ , R ⁷ , X ² and A are independent of each other. That is, when m is 2 or 3, the plurality of R ⁷ may have the same structure or different structures. When m is 2 or 3, a plurality of R ⁶ may be bonded to the same carbon atom of R ⁵ or may be bonded to different carbon atoms.

Specific examples of the repeating unit (c-3) include repeating units represented by general formulas (c-3a) to (c-3c).

In the general formulas (c-3a) to (c-3c), R ¹⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and L represents a methylene group substituted with a fluorine atom, or a carbon number of 2 20 represents a linear or branched fluoroalkylene group, and R ²⁰ represents a hydrogen atom or an acid dissociable group. In the general formulas (c-3a) and (c-3b), R ¹⁹ is a single bond or a divalent linear, branched or cyclic, saturated or unsaturated carbon atom having 1 to 20 carbon atoms. Indicates a hydrogen group. Furthermore, q represents the integer of 1-3 in general formula (c-3c). However, when q is 2 or 3, L and R ²⁰ are independent of each other.

Specific examples of the monomer that gives the repeating unit (c-3) include compounds represented by general formulas (Mc-3a) to (Mc-3f).

In the general formulas (M-3a) to (M-3f), R ¹⁶ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ²⁰ independently represents a hydrogen atom or an acid dissociable group. Show.

[1-6]: Repeating unit (c-4)
The fluorine-containing polymer of the present invention may have a repeating unit (c-4) represented by the following general formula (c-4) in addition to the repeating unit (c-1). When the fluorine-containing polymer contains the repeating unit (c-4), the shape of the resist pattern after development can be further improved.

  In general formula (c-4), R is synonymous with the description of general formula (c-1). Y represents an acid dissociable group.

Y in general formula (c-4) is preferably a group represented by general formula (i).

In the general formula (i), R ¹³ represents an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, and R ¹⁴ and R ¹⁵ are independently of each other, 2 to 4 carbon atoms having a carbon number of 1 to 4 or alicyclic hydrocarbon groups having a carbon number of 4 to 20 or formed together with carbon atoms bonded to each other. A valent alicyclic hydrocarbon group is shown.

Among the groups represented by R ^{13 to} R ¹⁵ in the general formula (i), examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n There are -butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. In addition, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, R ¹⁴ and R ¹⁵ are bonded to each other and formed together with the carbon atom to which each is bonded, and is a divalent divalent having 4 to 20 carbon atoms. Examples of the alicyclic hydrocarbon group include bridged skeletons such as an adamantane skeleton, norbornane skeleton, tricyclodecane skeleton, and tetracyclododecane skeleton, and cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A group having a skeleton; these groups are, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, etc. Group having an alicyclic skeleton such as a group substituted with one or more of linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms.
Among these, a group having a cycloalkane skeleton is preferable in that the shape of the resist pattern after development can be further improved.

Specific examples of the monomer for constituting the repeating unit (c-4) include (meth) acrylic acid 2-methyladamantan-2-yl ester and (meth) acrylic acid 2-methyl-3-hydroxyadamantane. -2-yl ester, (meth) acrylic acid 2-ethyladamantan-2-yl ester, (meth) acrylic acid 2-ethyl-3-hydroxyadamantan-2-yl ester, (meth) acrylic acid 2-n-propyl Adamantan-2-yl ester, (meth) acrylic acid 2-isopropyladamantan-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic Acid-2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-8-methyltricyclo [ .2.1.0 ^2,6] decan-8-yl ester, (meth) ethyl-8-acrylic acid tricyclo [5.2.1.0 ^2,6] decan-8-yl ester, (meth) 4-methyltetracycloacrylic acid [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester, (meth) acrylic acid-4-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl ester,

(Meth) acrylic acid 2- (bicyclo [2.2.1] hept-2-yl) -2-methylethyl ester, (meth) acrylic acid 2- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) -2-methyl ethyl ester, (meth) acrylic acid 2- (tetracyclo ^[6.2.1.1 3,6 ^{.0 2,7]} dodecane-4-yl) -2-methylethyl Ester, (meth) acrylic acid 2- (adamantan-2-yl) -2-methylethyl ester, (meth) acrylic acid 2- (3-hydroxyadamantan-2-yl) -2-methylethyl ester, (meth) 1,2-dicyclohexylethyl esteryl acrylate, 1,2-di (bicyclo [2.2.1] hept-2-yl) ethyl ester, (meth) acrylic acid 1,2-di (meth) acrylate Torishi B [5.2.1.0 ^2,6] decan-8-yl) ethyl ester, (meth) acrylic acid 1,2-di (tetracyclo ^[6.2.1.1 3,6 ^{.0 2,7} ] Dodecan-4-yl) ethyl ester, (meth) acrylic acid 1,2-di (adamantan-2-yl) ethyl ester, (meth) acrylic acid 2-methyl-2-cyclopentyl ester, (meth) acrylic acid 2 -Ethyl-2-cyclopentyl ester, (meth) acrylic acid 2-methyl-2-cyclohexyl ester, (meth) acrylic acid 2-ethyl-2-cyclohexyl ester, and the like.

  Among these monomers, (meth) acrylic acid 2-methyladamantan-2-yl ester, (meth) acrylic acid 2-ethyladamantan-2-yl ester, (meth) acrylic acid-2-methylbicyclo [2 2.1] hept-2-yl ester, (meth) acrylic acid-2-ethylbicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid 2- (bicyclo [2.2. 1] hept-2-yl) -2-methylethyl ester, (meth) acrylic acid 2- (adamantan-2-yl) -2-methylethyl ester, (meth) acrylic acid 2-methyl-2-cyclopentyl ester, (Meth) acrylic acid 2-ethyl-2-cyclopentyl ester, (meth) acrylic acid 2-methyl-2-cyclohexyl ester, (meth) acrylic acid 2-e Le 2-cyclohexyl ester.

  In addition, a polymer (A) may have a repeating unit (c-4) individually by 1 type or in combination of 2 or more types.

[1-7]: Repeating unit (c-5)

In addition to the repeating unit (c-1), the fluorine-containing polymer of the present invention has a repeating unit having an alkali-soluble group (hereinafter sometimes referred to as “repeating unit (c-5)”). It may be. When the fluorine-containing polymer contains the repeating unit (c-5), the affinity for the developer can be improved.
The alkali-soluble group in the repeating unit (c-5) is preferably a functional group having a pKa of 4 to 11 hydrogen atoms. This is from the viewpoint of improving solubility in a developer. Specific examples of such functional groups include functional groups represented by general formula (D3a) and formula (D3b).

In the general formula (D3a), R ²³ represents a C 1-10 hydrocarbon group substituted with a fluorine atom.

In the general formula (D3a), the hydrocarbon group having 1 to 10 carbon atoms substituted with a fluorine atom represented by R ²³ is such that one or more hydrogen atoms in the hydrocarbon group having 1 to 10 carbon atoms are fluorine atoms. Although it will not specifically limit if substituted by, For example, a trifluoromethyl group etc. are preferable.

  The main chain skeleton of the repeating unit (D3) is not particularly limited, but is preferably a skeleton such as methacrylic acid ester, acrylic acid ester, or α-trifluoroacrylic acid ester.

  As the repeating unit (D3), for example, there are repeating units derived from the compounds represented by the general formulas (D3a-1) and (D3b-1).

In the general formulas (D3a-1) and (D3b-1), R ²⁴ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ²⁵ represents a single bond or a divalent group having 1 to 20 carbon atoms. A linear, branched or cyclic, saturated or unsaturated hydrocarbon group is shown. In General Formula (D3a-1), R ²³ represents a C 1-10 hydrocarbon group substituted with a fluorine atom.

In general formulas (D3a-1) and (D3b-1), the group represented by R ^{25 is the same} as R ² in general formula (c-1). Further, in the general formula ^(D3a-1), with respect to the group represented by ^{R 23,} the same can be said with ^{R 23} in the general formula (D3a).

[1-8]: Repeating unit (c-6)
The fluorine-containing polymer of the present invention may have a repeating unit (c-6) represented by the following general formula (c-6) in addition to the repeating unit (c-1). When the fluorine-containing polymer contains the repeating unit (C-6), the affinity for the developer can be improved.

  In general formula (c-6), R is synonymous with the description of general formula (c-1). Z represents a group having a lactone skeleton or a group having a cyclic carbonate structure.

[1-8a]: Repeating unit (c-6a)
Among the repeating units (2-2), examples of the repeating unit having a group having a lactone skeleton include repeating units represented by general formulas (2-2-1a) to (2-2-1f).

In the general formulas (2-2-1a) to (2-2-1f), R has the same meaning as in the description of the general formula (c-1). Moreover, in general formula (2-2-1a), R < ^a1 > shows a hydrogen atom or the alkyl group which may have a C1-C4 substituent, and s1 shows the integer of 1-3. Furthermore, in the general formulas (2-2-1d) and (2-2-1e), R ^a4 represents a hydrogen atom or a methoxy group. In general formulas (2-2-1b) and (2-2-1c), R ^a2 represents a single bond, an ether group, an ester group, a carbonyl group, or a divalent chain hydrocarbon having 1 to 30 carbon atoms. A divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a divalent group obtained by combining these, s2 is 0 or 1. Furthermore, in the general formulas (2-2-1c) and (2-2-1e), R ^a3 represents an oxygen atom or a methylene group.

  Examples of the monomer that gives such a repeating unit include those described in paragraph [0043] of International Publication No. 2007/116664.

Of these monomers, the following can be mentioned.
[1-8b]: Repeating unit (C-6b)
Examples of the repeating unit having a group having a cyclic carbonate structure include a repeating unit represented by the general formula (2-2-2).

In general formula (2-2-2), R is as defined in formula (c-1). D represents a trivalent chain hydrocarbon group having 1 to 30 carbon atoms, a trivalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, or a trivalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Show. D may have an oxygen atom, a carbonyl group, or an imino group in its skeleton. D may have a substituent. However, in the general formula (2-2-2), the following partial structure is necessarily formed.

  In said formula, t shows the integer of 1-4.

Examples of the substituent that D may have include the same groups as those described above for R ¹⁰ and hydroxyl groups.

  Monomers that give a repeating unit represented by the general formula (2-2-2) are described in, for example, Tetrahedron Letters, Vol. 27, no. 32 p. 3741 (1986), Organic Letters, Vol. 4, no. 15 p. 2561 (2002), etc., and can be synthesized by a conventionally known method.

Particularly preferred examples of the repeating unit represented by the general formula (2-2-2) include repeating units represented by the general formulas (2-2-2a) to (2-2-2v).

[1-9]: Content ratio of each repeating unit:
The content ratio of the repeating unit (c-1) is preferably 10 mol% or more, and more preferably 50 mol% or more. When the content ratio of the repeating unit (c-1) is within the above range, it is particularly preferable from the viewpoint of ensuring water repellency at the time of immersion exposure and improving the affinity to the developer at the time of development.

  Moreover, it is preferable that the content rate of a repeating unit (c-2) or a repeating unit (c-3) is 20-90 mol%, It is more preferable that it is 20-80 mol%, It is 20-70 mol% Is particularly preferred. When the content ratio of the repeating unit (c-2) or the repeating unit (c-3) is within this range, it is said that both water repellency after coating and improved affinity for the developer after PEB are achieved. This is particularly effective from the viewpoint.

  Furthermore, the content of the repeating unit (c-4) is preferably 80 mol% or less, more preferably 20 to 80 mol%, and particularly preferably 30 to 70 mol%. When the content ratio of the repeating unit (c-4) is within this range, it is particularly effective from the viewpoint of improving the resist pattern shape after development.

  Furthermore, the content rate of a repeating unit (c-5) is 50 mol% or less normally, Preferably it is 5-30 mol%, More preferably, it is 5-20 mol%. When the content ratio of the repeating unit (c-5) is within this range, it is particularly effective from the viewpoint of ensuring water repellency after coating and increasing the contact angle with respect to the developer after PEB.

  Moreover, the content rate of a repeating unit (c-6) is 50 mol% or less normally, Preferably it is 5-30 mol%, More preferably, it is 5-20 mol%. When the content ratio of the repeating unit (D4) is within this range, it is particularly effective from the viewpoint of both ensuring water repellency after coating and increasing the contact angle with respect to the developer after PEB.

[1-10] Physical property values:
The Mw of the polymer (C) is preferably 1,000 to 50,000, more preferably 1,000 to 40,000, and particularly preferably 1,000 to 30,000. When Mw is less than 1,000, there is a possibility that a resist film having a sufficient receding contact angle cannot be obtained. On the other hand, if it exceeds 50,000, the developability of the resist film may be lowered. Further, the ratio (Mw / Mn) of the polymer (C) Mw and the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) by GPC method is preferably 1 to 5, preferably 1 to 4. More preferably it is.

  In addition, a polymer (C) is so preferable that there is little content of impurities, such as a halogen and a metal. When the content of such impurities is small, the sensitivity, resolution, process stability, pattern shape and the like of the resist film can be further improved.

[1-11] Preparation of polymer (C):
The polymer (C) uses a fluorine-containing compound represented by the following general formula (m-1) (hereinafter sometimes referred to as “compound (m-1)”) as a monomer component, and includes a radical polymerization initiator and The polymer (C) can be obtained by polymerizing in an appropriate solvent in the presence of a chain transfer agent as necessary. In this case, as the “radical polymerization initiator”, hydroperoxides, dialkyl peroxides, diacyl peroxides, azo compounds and the like can be used.

In General Formula (m-1), R ¹ and A have the same meaning as in the description of General Formula (x), and R ² , R ³ , R, and n have the same meaning as in the description of General Formula (c-1). When n is 2 or 3, R ¹ , R ² and A are the same as in the general formula (c-1) in that they are mutually independent.

  Examples of the solvent include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane and n-decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane. Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cumene; halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide and chlorobenzene; ethyl acetate, n-butyl acetate, i-acetate Saturated carboxylic acid esters such as butyl and methyl propionate; ethers such as tetrahydrofuran, dimethoxyethane and diethoxyethane. These solvents can be used alone or in combination of two or more. Moreover, reaction temperature is 40-120 degreeC normally, Preferably it is 50-90 degreeC, and reaction time is 1-48 hours normally, Preferably it is 1-24 hours.

[1-11-1] Fluorine-containing compound:
As a fluorine-containing compound, the compound represented by the following general formula (m-1-1) or the compound represented by the following general formula (m-1-2) can be mentioned, for example.

[In General Formula (m-1-1), R, R ¹ , R ² , R ^3, and X ¹ have the same meaning as in the description of General Formula (c-1). R ⁸ has the same meaning as in the description of General Formula (R1-1). ]

[In General Formula (m-1-2), R and X ¹ have the same meaning as in the description of General Formula (c-1). R ⁹ represents any one of groups represented by the above formulas (R1-2) to (R1-4). R ³¹ has the same meaning as in the description of the general formula (c-1a-2). ]

上記式中、Ｒは一般式（ｃ−１）の説明におけるものと同義である。Ｒ^８は式（Ｒ１−１）の説明におけるものと同義である。 Specific examples of such a compound include compounds represented by the following formula.

In said formula, R is synonymous with the thing in description of general formula (c-1). R ⁸ has the same meaning as in the description of formula (R1-1).

［一般式（ｍ−２−１）中、Ｒ、Ｒ^２、Ｒ^３、及びＸ１は一般式（ｃ−１）の説明におけるものと同義である。］

［一般式（ｍ−２−２）中、Ｒ^８は一般式（Ｒ１−１）の説明におけるものと同義である。Ｒ^８１は水酸基、ハロゲン原子又は−Ｏ−ＣＯ−Ｒ^８を示す。］ In order to give the compound (m-1-1), for example, a compound represented by the following general formula (m-2-1) and a compound represented by the following general formula (m-2-1) are reacted. Can be obtained.

[In General Formula (m-2-1), R, R ² , R ³ , and X1 have the same meanings as in the description of General Formula (c-1). ]

[In General Formula (m-2-2), R ⁸ has the same meaning as in the description of General Formula (R1-1). R ⁸¹ represents a hydroxyl group, a halogen atom or —O—CO—R ⁸ . ]

In order to give the compound (m-1-2), for example, a compound represented by the following general formula (m-2-3) and the following formulas (m-2-4-1) to (m-2-2) It can be obtained by reacting with the compound represented by 4-3).

一般式（ｍ−２−４−１）及び一般式（ｍ−２−４−２）中、Ｒ^１０は式（Ｒ９−２）の説明と同義である。一般式（ｍ−２−４−１）中、Ｒ^９２はハロゲン原子を示し、好ましくはＣｌである。ｍ１は０〜５の整数を示す。一般式（ｍ−２−４−２）中、Ｒ^９３はハロゲン原子を示し、好ましくはＢｒである。ｍ２は０〜４の整数を示す。 In general formula (m-2-3), R and X ¹ have the same meanings as in the description of general formula (c-1). R ³¹ has the same meaning as in the description of the general formula (c-1a-2). R ⁹¹ represents a hydroxyl group or a halogen atom.

In general formula (m-2-4-1) and general formula (m-2-4-2), R ¹⁰ has the same meaning as in the description of formula (R9-2). In general formula (m-2-4-1), R ⁹² represents a halogen atom, preferably Cl. m1 represents an integer of 0 to 5. In general formula (m-2-4-2), R ⁹³ represents a halogen atom, preferably Br. m2 represents an integer of 0 to 4.

It can also be obtained by reacting a compound represented by the following formula (m-2-5) with a compound represented by the following formula (m-2-6).

In the general formula (m-2-5), R ³¹ , X ¹ and R ⁹ are as defined in the formula (m-2-3). In general formula (m-2-6), R has the same meaning as in the description of formula (m-2-3). Rh represents a hydroxyl group or a halogen atom.

  The method for obtaining the formula (m-2-5) is not particularly limited, but for example, it can be obtained by the method described in paragraphs [0112] to [0123] of JP-A-2009-19199.

[2]: Radiation sensitive resin composition:
The radiation-sensitive resin composition of the present invention contains the polymer (C) and the acid generator (B) as essential components in addition to the polymer (C), and other optional components depending on the purpose. To do.

  Since the radiation-sensitive resin composition of the present invention contains the polymer (C) of the present invention described above as an essential component, an upper layer film is separately formed for the purpose of blocking the photoresist film and the immersion medium. Therefore, it can be suitably used for the immersion exposure method.

  The polymer (C) has a radiation sensitivity of 0.1 to 20 parts by mass based on 100 parts by mass of the polymer (A) described later. It is preferable from the viewpoint of shape. If the content of the polymer (C) is too small, the effect of adding the polymer (C) may not be obtained. If the content of the polymer (C) is excessive, there is a risk of significant damage to patterning such as T-top shape and scum generation.

[2-1]: Polymer (A):
An “acid-dissociable polymer” is a polymer having an acid-dissociable group. More specifically, it is a polymer that is insoluble or hardly soluble in alkali before the action of acid and becomes alkali-soluble when an acid-dissociable group is eliminated by the action of acid.

  “Alkali insoluble or hardly soluble in alkali” means that the resist is developed under alkaline development conditions employed when a resist pattern is formed from a resist film formed using a radiation-sensitive resin composition containing the polymer (A). When a 100 nm thick film using only the polymer (A) is developed instead of the film, 50% or more of the initial film thickness remains after development.

[2-1-1] Fluorine atom content:
The fluorine atom content ratio in the polymer (A) is less than 5% by mass, preferably 0 to 4.9% by mass, and more preferably 0 to 4% when the entire polymer (A) is 100% by mass. % By mass. The fluorine content can be measured by ¹³ C-NMR. When the fluorine atom content in the polymer (A) is within the above range, the water repellency of the resist coating surface formed by the radiation-sensitive resin composition containing the fluorine-containing polymer and the polymer (A) described above is improved. Therefore, it is not necessary to separately form an upper layer film during immersion exposure.

  As long as the polymer has the above properties, the specific structure of the polymer (A) is not particularly limited. However, the repeating unit represented by the general formula (c-3) (hereinafter referred to as “repeating unit (2-1)”) and the repeating unit represented by the general formula (c-6) (hereinafter referred to as “repeating unit”). (2-2) ") is preferable.

[2-1-2] Repeating unit (2-1):
In the polymer (A), the content of the repeating unit (2-1) is preferably 15 to 85 mol%, more preferably 25 to 75 mol%, and particularly preferably 35 to 60 mol%. . If it is less than 15 mol%, the contrast after dissolution is impaired, and the pattern shape may be lowered. On the other hand, if it exceeds 85 mol%, the adhesion to the substrate is insufficient and the pattern may be peeled off.

[2-1-3] Repeating unit (2-2):
In the polymer (A), the content of the repeating unit (2-2) is preferably 5 to 75 mol%, more preferably 15 to 65 mol%, and particularly preferably 25 to 55 mol%. . If it is less than 5 mol%, the resist may have insufficient adhesion to the substrate and the pattern may be peeled off. On the other hand, if it exceeds 75 mol%, the contrast after dissolution is impaired, and the pattern shape may be lowered.

[2-1-4] Other repeating units:
The polymer (A) may have another repeating unit other than the repeating units (2-1) and (2-2) as long as it has the fluorine atom content. As the polymerizable unsaturated monomer constituting the other repeating unit, International Publication No. 2007 / 116664A, [0047] to [0048] paragraph, [0073] to [0077] paragraph, and [0079] to [0082] paragraph And monomers disclosed in (1).

  The weight average molecular weight (hereinafter referred to as “Mw”) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer (A) is usually 3,000 to 300,000, preferably 4,000 to 200. 1,000, more preferably 4,000 to 100,000. If the Mw is less than 3,000, the heat resistance as a resist may decrease. On the other hand, if it exceeds 300,000, developability as a resist may be lowered.

  The polymer (A) is preferably as less as possible as impurities such as halogen and metal from the viewpoint of improving the sensitivity, resolution, process stability, pattern shape and the like as a resist. Examples of the purification method of the polymer (A) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. is there. In addition, the radiation sensitive resin composition of this invention can mix | blend a polymer (A) individually by 1 type or in combination of 2 or more types.

[2-2] Acid generator (B):
(B) The radiation-sensitive acid generator ((B) acid generator) generates an acid upon irradiation with radiation (hereinafter referred to as “exposure”). (B) The acid generator dissociates the acid dissociable group present in the polymer (A) by the action of the acid generated by exposure, and makes the polymer (A) alkali-soluble. As a result, the exposed portion of the resist film becomes readily soluble in an alkali developer, and a positive resist pattern can be formed. Examples of the acid generator (B) include compounds described in paragraphs [0080] to [0113] of JP2009-134088A.

  (B) Specific examples of the acid generator include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, and bis (4-t-butylphenyl) iodonium. Trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium Nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, cyclohexyl 2-oxocyclohexyl Le methyl trifluoromethanesulfonate, dicyclohexyl-2-oxo-cyclohexyl trifluoromethane sulfonate, 2-oxo-cyclohexyl dimethyl sulfonium trifluoromethane sulfonate, 4-hydroxy-1-naphthyl dimethyl sulfonium trifluoromethane sulfonate,

  4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium nonafluoro-n-butanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium perfluoro-n- Octanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (1-naphthylacetomethyl) Tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- 3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro -n- butane sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro -n- octane sulfonate,

  Trifluoromethanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, nonafluoro-n-butanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide , Perfluoro-n-octanesulfonylbicyclo [2.2.1] hept-5-ene-2,3-dicarbodiimide, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide nonafluoro-n- Butanesulfonate, N-hydroxysuccinimide perfluoro-n-octanesulfonate, and 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate are preferred. In addition, (C) acid generator can be contained individually by 1 type or in combination of 2 or more types.

  The content of the (B) acid generator is preferably 0.1 to 30 parts by mass, more preferably 2 to 27 parts by mass, with respect to 100 parts by mass of the (A) polymer. Particularly preferred is 25 parts by mass. If it is less than 0.1 parts by mass, the sensitivity and resolution as a resist film may be lowered. On the other hand, if it exceeds 30 parts by mass, the coatability and pattern shape as a resist film may be deteriorated.

[2-3] Other components:
The radiation-sensitive resin composition of the present invention includes an acid diffusion controller, an alicyclic additive, a surfactant, a sensitizer, an antihalation agent, an adhesion aid, a storage stabilizer, Various additives such as foaming agents can be contained.

（上記一般式（１０）中、Ｒ^４５〜Ｒ^４７は、相互に独立に、水素原子、置換されていてもよい、直鎖状、分岐状若しくは環状のアルキル基、アリール基、又はアラルキル基を示す。） [2-3-1] Acid diffusion controller:
Examples of the acid diffusion controller include a compound represented by the general formula (10) (hereinafter referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound”). Compound (II) ”, compounds having 3 or more nitrogen atoms (hereinafter referred to as“ nitrogen-containing compound (III) ”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. When an acid diffusion control agent is contained, the pattern shape and dimensional fidelity as a resist can be improved.

(In the general formula (10), R ^{45 to} R ⁴⁷ each independently represent a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, aryl group, or aralkyl group. Show.)

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n- Dialkylamines such as pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, Trialkylamines such as tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methyl Ruaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, 1-naphthylamine, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl)- Aromatic amines such as 2- (4-hydroxyphenyl) propane can be exemplified.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tetramethylenediamine, Hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2′-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- ( 4-aminophenyl) -1-methylethyl] benzene and the like.

  Examples of the nitrogen-containing compound (III) include polymers of polyethyleneimine, polyallylamine, dimethylaminoethylacrylamide, and the like.

  Examples of amide group-containing compounds include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. Can be mentioned.

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like. Can do.

  Examples of the nitrogen-containing heterocyclic compound include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, and N-methyl-4-phenylpyridine. , Nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, pyridines such as acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1, 4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned.

  Among these acid diffusion control agents, nitrogen-containing compounds (I), nitrogen-containing compounds (II), and nitrogen-containing heterocyclic compounds are preferable. In addition, an acid diffusion control agent can be used individually by 1 type or in combination of 2 or more types. The content of the acid diffusion controller is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, with respect to 100 parts by mass of the polymer (B). When the content of the acid diffusion control agent is excessive, the sensitivity of the formed resist film tends to be remarkably lowered.

[2-3-2] Alicyclic additive:
An alicyclic additive is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Examples of such alicyclic additives include 1-adamantanecarboxylate t-butyl, 1-adamantanecarboxylate t-butoxycarbonylmethyl, 1,3-adamantanedicarboxylate di-t-butyl, 1-adamantaneacetic acid. adamantane derivatives such as t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl; deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxychol Deoxycholic acid esters such as 2-ethoxyethyl acid, 2-cyclohexyloxyethyl deoxycholic acid, 3-oxocyclohexyl deoxycholic acid, tetrahydropyranyl deoxycholic acid, mevalonolactone ester deoxycholic acid; t-butyl lithocholic acid , Lithocholic acid esters such as t-butoxycarbonylmethyl cholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, tetrahydropyranyl lithocholic acid, mevalonolactone ester of lithocholic acid, etc. Can be mentioned. These alicyclic additives can be used individually by 1 type or in mixture of 2 or more types. Content of an alicyclic additive is 50 mass parts or less normally with respect to 100 mass parts of (B) polymers, Preferably it is 30 mass parts or less.

[2-3-3] Surfactant:
A surfactant is a component that exhibits an effect of improving coatability, developability, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), Megafax F171, F173 (above, manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 ( As mentioned above, Asahi Glass Co., Ltd.) can be mentioned. These surfactants can be used individually by 1 type or in mixture of 2 or more types. The content of the surfactant is usually 2 parts by mass or less with respect to 100 parts by mass of the polymer (B).

[2-4] Preparation of composition solution:
The radiation sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content concentration is 1 to 50% by mass, preferably 3 to 25% by mass, and then, for example, the pore size is 0.02 μm. It is prepared as a composition solution by filtering with a filter of a degree.

  Examples of the solvent used for the preparation of the composition solution include linear or branched ketones; cyclic ketones; propylene glycol monoalkyl ether acetates; alkyl 2-hydroxypropionate; 3-alkoxypropion. In addition to alkyl acids

  n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether , Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether , Propylene glycol monoethyl Ether, propylene glycol mono -n- propyl ether,

  Toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3 -Methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, caproic acid, caprylic acid, 1-o Pentanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, .gamma.-butyrolactone, ethylene carbonate, propylene carbonate and the like.

  These solvents can be used singly or in combination of two or more, and among these, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates , Alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate and the like are preferable.

[3] Method for forming resist pattern:
The resist pattern forming method of the present invention includes a film forming step (1), an exposure step (2), and a developing step (3) as essential steps.

[3-1]: Film formation step (1):
A film formation process (1) is a process of forming the resist film which consists of a radiation sensitive resin composition of this invention on a board | substrate. For example, the solution of the radiation-sensitive resin composition of the present invention is applied on a substrate by a coating method such as spin coating, cast coating, roll coating, and the like to form a resist film.

  As the substrate, for example, a silicon wafer, a wafer coated with aluminum, or the like can be used. The thickness of the resist film is preferably 0.1 to 5 μm, and more preferably 0.1 to 2 μm.

  In the film forming step, pre-baking (PB) may be performed in order to volatilize the solvent in the film. Although the prebaking heating conditions differ depending on the composition of the radiation-sensitive resin composition, it is preferably 30 to 200 ° C, more preferably 50 to 150 ° C.

In order to maximize the potential of the radiation sensitive resin composition, an organic or inorganic antireflection film may be formed on the substrate (see, for example, Japanese Patent Publication No. 6-12458). Further, a protective film may be formed on the resist film in order to prevent the influence of basic impurities and the like contained in the environmental atmosphere (see, for example, JP-A-5-188598). Furthermore, these techniques may be used in combination.

[3-2] Exposure step (2):
The exposure step (2) is a step of exposing the resist film by irradiating the resist film with radiation through a mask pattern. When the resist film is irradiated with radiation, an acid derived from the acid generator (B) is generated in the exposed area, and the acid-dissociable group in the polymer (A) is dissociated by the action of the acid, and is initially insoluble or difficult to alkali. The soluble polymer (A) is converted into an alkali-soluble polymer.

  The radiation to be irradiated may be appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams and the like according to the type of the acid generator (B). However, among these radiations, it is preferable to irradiate an ArF excimer laser (wavelength 193 nm) or a KrF excimer laser (wavelength 248 nm).

  In addition, after exposure, it is preferable to perform post exposure baking (PEB). By this PEB, the dissociation reaction of the acid dissociable group in the polymer (A) proceeds smoothly. The heating conditions for PEB vary depending on the composition of the radiation-sensitive resin composition, but are usually 30 to 200 ° C, preferably 50 to 170 ° C.

  In the exposure step (2), an immersion exposure liquid is preferably disposed on the resist film formed in the film formation step (1), and the resist film is exposed through the immersion exposure liquid. (Immersion exposure).

  As the liquid for immersion exposure, for example, pure water, a long chain or cyclic aliphatic compound, or the like can be used.

  Usually, in immersion exposure, an upper layer film (protective film) is formed on the resist film in order to prevent the acid generator and the like from flowing out of the resist film (see, for example, JP-A-2005-352384). However, when the resist film is formed using the radiation sensitive resin composition of the present invention, it is not always necessary to form the upper layer film. Thus, the method without providing the upper layer film can omit the step of forming the upper layer film and can be expected to improve the throughput.

[3-3] Development step (3):
The development step (3) is a step of developing the exposed resist film to form a resist pattern. The polymer (A) converted to alkali-soluble in the exposure step (2) is dissolved and removed by an alkali developer, and a positive resist pattern is formed. Usually, after the development step (3), washing with water and drying are performed.

  Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3.0 An alkaline aqueous solution in which at least one of alkaline compounds such as -5-nonene is dissolved is preferable.

The concentration of the alkaline aqueous solution is usually 10% by mass or less. If the concentration of the alkaline aqueous solution is more than 10% by mass, the unexposed area may be dissolved in the developer.

  Moreover, you may add an organic solvent and surfactant to the developing solution which consists of alkaline aqueous solution. Examples of the organic solvent include linear, branched or cyclic ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methanol , Ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol, and the like; tetrahydrofuran And ethers such as dioxane; esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide.

  These organic solvents can be used individually by 1 type or in mixture of 2 or more types. The amount of the organic solvent used is preferably 100% by volume or less with respect to the alkaline aqueous solution. If the amount of the organic solvent used is more than 100% by volume, the developability may be deteriorated and the development residue in the exposed area may increase.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are on a molar basis unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

[Measurement of receding contact angle]:
First, a film was formed on a substrate (wafer) with the radiation sensitive resin composition. Thereafter, the receding contact angle of the formed film was calculated in the following procedure using “DSA-10” manufactured by KRUS under an environment of room temperature 23 ° C., humidity 45%, and normal pressure.

  First, the wafer stage position is adjusted. Next, the wafer is set on the stage. Water is injected into the “DSA-10” needle. Next, the position of the needle is finely adjusted. Next, water is discharged from the needle to form a 25 μL water droplet on the wafer, and then the needle is once pulled out of the water droplet. Next, the needle is pulled down again to the finely adjusted position. Next, a water droplet is sucked with a needle at a speed of 10 μL / min for 90 seconds, and the contact angle is measured every second (total 90 times). Next, an average value is calculated for a total of 20 contact angles from the time when the contact angle is stabilized, and is set as the receding contact angle (°).

  A substrate with a film thickness of 110 nm was formed on an 8-inch silicon wafer with a radiation-sensitive resin composition, and the substrate was subjected to soft baking (SB) at 120 degrees for 60 seconds. "

  A film having a film thickness of 110 nm was formed on an 8-inch silicon wafer with a radiation-sensitive resin composition, and soft baking (SB) was performed at 120 degrees for 60 seconds. Thereafter, the substrate was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and the receding contact angle of the dried substrate was defined as “the receding contact angle after development”.

[Development defects]:
First, a coating having a film thickness of 110 nm is formed from a radiation-sensitive resin composition on a 12-inch silicon wafer on which an underlayer antireflection film (“ARC66”, manufactured by Nissan Chemical Co., Ltd.) is formed, and soft baking is performed at 120 degrees for 60 seconds. (SB) was performed. Next, this film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, Dipole. did. After the exposure, post-baking (PEB) was performed at 95 ° C. for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern. At this time, the exposure amount for forming a line and space having a width of 45 nm was determined as the optimum exposure amount. With this optimum exposure amount, a line and space having a line width of 45 nm was formed on the entire surface of the wafer to obtain a defect inspection wafer. A scanning electron microscope (“CC-4000”, manufactured by Hitachi High-Technologies Corporation) was used for length measurement.

  Thereafter, the number of defects on the defect inspection wafer was measured using “KLA2810” manufactured by KLA-Tencor. Furthermore, the defects measured by “KLA2810” were classified into those judged to be resist-derived and foreign matters derived from the outside. After classification, if the total number of defects determined from the resist film (number of defects) was less than 100 pieces / wafer, “good”, if 100 to 500 pieces / wafer, “slightly good” When exceeding 500 pieces / wafer, it was determined as “bad”.

[Pattern shape of pattern]:
First, a coating having a film thickness of 110 nm is formed from a radiation-sensitive resin composition on a 12-inch silicon wafer on which an underlayer antireflection film (“ARC66”, manufactured by Nissan Chemical Co., Ltd.) is formed, and soft baking is performed at 120 degrees for 60 seconds. (SB) was performed. Next, this film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, Dipole. did. After the exposure, post-baking (PEB) was performed at 95 ° C. for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern.

  The cross-sectional shape of the formed pattern is observed with “S-4800” manufactured by Hitachi High-Technologies Corporation, and the line width Lb in the middle part of the film in the thickness direction of the film and the line width La on the film surface are measured. did. Thereafter, the formula: (La−Lb) / Lb is calculated, and when the calculated value is 0.90 <(La−Lb), “T-top” is set, and (La−Lb) <1.1. In this case, the top round was selected. When 0.90 ≦ (La−Lb) ≦ 1.1, it was determined as “good”. Further, when melted residue was generated in the exposed portion, it was determined as “scum”.

[Mask error factor (MEF)]
First, a coating having a film thickness of 110 nm is formed from a radiation-sensitive resin composition on a 12-inch silicon wafer on which an underlayer antireflection film (“ARC66”, manufactured by Nissan Chemical Co., Ltd.) is formed, and soft baking is performed at 120 degrees for 60 seconds. (SB) was performed. Next, this film is exposed through a mask pattern using an ArF excimer laser immersion exposure apparatus (“NSR S610C”, manufactured by NIKON) under the conditions of NA = 1.3, ratio = 0.800, Dipole. did.

  After the exposure, post-baking (PEB) was performed at 95 ° C. for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern. At this time, the exposure amount for forming a line and space having a width of 45 nm was determined as the optimum exposure amount. In the above Eop, LS patterns with a pitch of 90 nm were formed using mask patterns with target sizes of 40 nm, 42 nm, 44 nm, 46 nm, 48 nm, and 50 nm, respectively.

  At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEF. As the MEF (straight line) is closer to 1, the reproducibility of the mask is better. When the value is 1.10 ≦ MEF <1.25, “good” is set, and 1.25 ≦ MEF <1. The case of 50 was “slightly good”, and 1.50 ≦ MEF was “bad”. The results obtained are shown in the table.

(Synthesis Example 1)
2- (2,2,2-trifluoroacetoxy) ethyl methacrylate (compound represented by the formula (M-16)) was synthesized.

After replacing the reactor sufficiently dried by vacuum heating with dry nitrogen, 130.14 g (1.0 mol) of 2-hydroxyethyl methacrylate and 500 mL of methyl isobutyl ketone (MIBK) were placed in the reactor. added. The mixture was cooled to 0 ° C. in an ice bath, and 231.03 g (1.1 mol) of trifluoroacetic anhydride was added over 30 minutes while stirring. Then, what melt | dissolved 92.41 g (1.1 mol) of sodium hydrogencarbonate in 500 mL of water was added, stirring well. Thereafter, the MIBK layer was separated, and the aqueous layer was extracted again with MIBK to obtain an extract. This extract was combined with the MIBK layer, washed with saturated saline, and then dried over sodium sulfate (desiccant). Thereafter, the desiccant was filtered off with a Buchner funnel, the organic solvent was distilled off, and the residue was distilled under reduced pressure under 2 mmHg. In this way, 2- (2,2,2-trifluoroacetoxy) ethyl methacrylate (207.34 g (yield 92%)) was obtained.

In addition, ¹ H-NMR data of 2- (2,2,2-trifluoroacetoxy) ethyl methacrylate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.95 (s, 3H, C—CH ₃ ), 4.45 (m, 3H, CH ₂ ), 4.62 (m, 3H, CH ₂ ), 5. 62 (s, 1H, C = CH ₂ ), 6.13 (s, 1H, C = CH ₂ )

(Synthesis Example 2)
A compound represented by the formula (M-17) was synthesized.

  In a nitrogen atmosphere at 0 ° C., 200 mL of 4-methyl-2-pentanone was added to 29.42 g (100 mmol) of 5,5,5-trifluoro-4-hydroxy-4- (trifluoromethyl) pentan-2-yl methacrylate. added. Thereafter, 23.10 g (100 mmol) of trifluoroacetic anhydride was added dropwise over 30 minutes. Then, after stirring at room temperature for 2 hours, an aqueous sodium hydrogen carbonate solution was added to stop the reaction. 4-Methyl-2-pentanone was added to the reaction solution for extraction three times, and the obtained organic layer was washed once with water and saturated brine, and dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography, and 5,5,5-trifluoro-4- (2,2,2) represented by the above formula (M-17). 17.29 g of 2-trifluoroacetoxy) -4- (trifluoromethyl) pentan-2-yl methacrylate was obtained (44% yield).

¹ H-NMR of 5,5,5-trifluoro-4- (2,2,2-trifluoroacetoxy) -4- (trifluoromethyl) pentan-2-yl methacrylate obtained in this example The data is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.35 (d, 3H, CH ₃ ), 1.92 (s, 3H, CH ₃ ), 2.70-2.90 (m, 2H, CH ₂ ), 5.11-5.22 (m, 1H, O—CH), 5.47 (s, 1H, C═CH ₂ ), 6.10 (s, 1H, C═CH ₂ )

(Synthesis Example 3)
A compound represented by the formula (M-18) was synthesized.

  Under a nitrogen atmosphere, 400 mL of dehydrated methylene chloride and 11.13 g (110 mmol) of triethylamine were added to 11.51 g (50 mmol) of 4-[(2-methacryloyloxy) ethoxy] -4-oxobutyric acid at 0 ° C. Thereafter, 17.06 g (100 mmol) of benzyl chloroformate was added dropwise over 10 minutes. Thereafter, the mixture was stirred at room temperature for 2 hours. After confirming the disappearance of the raw material by thin layer chromatography (TLC), an aqueous sodium hydrogen carbonate solution was added to stop the reaction. Thereafter, ethyl acetate was added to the reaction solution to perform extraction three times. The obtained organic layer was washed once with water and saturated brine, and dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography to obtain 11.21 g of benzyl 2- (methacryloyloxy) ethyl succinate represented by the above formula (M-19). (Yield 70%).

In addition, ¹ H-NMR data of ¹ -benzyl 2- [2- (methacryloyloxy) ethyl] cyclohexane-1,2-dicarboxylate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.94 (s, 3H, C—CH ₃ ), 2.55-2.71 (m, 4H, C (═O) CH ₂ ), 4.26-4 .45 (m, 4H, O—CH ₂ ), 5.12-5.28 (m, 2H, Ar—CH ₂ ), 5.59 (s, 1H, C═CH ₂ ), 6.12 (s _{, 1H, C = CH 2)} , 7.28-7.49 (m, 5H, Ar)

(Synthesis Example 4)
A compound represented by the formula (M-19) was synthesized.

  Under a nitrogen atmosphere, at 0 ° C., 400 mL of dehydrated methylene chloride and 11.13 g (110 mmol) of triethylamine were added to 28.43 g (100 mmol) of 2-{[2- (methacryloyloxy) ethoxy] carbonyl} cyclohexanecarboxylic acid. Thereafter, 17.06 g (100 mmol) of benzyl chloroformate was added dropwise over 10 minutes. Thereafter, the mixture was stirred at room temperature for 2 hours. After confirming the disappearance of the raw material by thin layer chromatography (TLC), an aqueous sodium hydrogen carbonate solution was added to stop the reaction. Thereafter, ethyl acetate was added to the reaction solution to perform extraction three times. The obtained organic layer was washed once with water and saturated brine, and dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography, and 1-benzyl 2- [2- (methacryloyloxy) ethyl] cyclohexane- represented by the above formula (M-19). 26.66 g of 1,2-dicarboxylate was obtained (yield 71%).

In addition, ¹ H-NMR data of ¹ -benzyl 2- [2- (methacryloyloxy) ethyl] cyclohexane-1,2-dicarboxylate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.31-2.26 (m, 8H, CH ₂ ), 1.92 (s, 3H, CH ₃ ), 2.87-2.91 (m, 2H, _{CH), 4.18-4.42 (m, 4H} , O-CH 2), 5.17-5.30 (m, 2H, Ar-CH 2), 5.59 (s, 1H, C = CH _{2), 6.11 (s, 1H} , C = CH 2), 7.29-7.51 (m, 5H, Ar)

(Synthesis Example 5)
(1,3-Dioxoisoindoline-2-yl) methyl 2- (methacryloyloxy) ethyl succinate (compound represented by formula (M-20)) was synthesized.

After replacing the reactor sufficiently dried by vacuum heating with dry nitrogen, 11.51 g (0.05 mol) of 4-[(2-methacryloyloxy) ethoxy] -4-oxobutyric acid was added to the reactor. ), 6.07 g (0.06 mol) of triethylamine, and 150 mL of dimethylformamide (DMF) were added. A solution prepared by dissolving 12.00 g (0.05 mol) of N- (bromomethyl) phthalimide in 100 mL of DMF was added over 15 minutes while stirring at 65 ° C. in an oil bath. After stirring for 1 hour, DMF was distilled off with a rotary evaporator, and the residue was extracted with ethyl acetate to obtain an extract. This extract was washed three times with water, then washed successively with a saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over sodium sulfate (desiccant). Thereafter, the desiccant was filtered off with a Buchner funnel, and then the organic solvent was distilled off. Thus, (1,3-dioxoisoindoline-2-yl) methyl 2- (methacryloyloxy) ethyl succinate (13.95 g (yield 72%)) was obtained.

The ¹ H-NMR data of (1,3-dioxoisoindoline-2-yl) methyl 2- (methacryloyloxy) ethyl succinate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.94 (s, 3H, C—CH ₃ ), 2.57-2.74 (m, 4H, C (═O) CH ₂ ), 4.26-4 .43 (m, 4H, O—CH ₂ ), 5.59 (s, 1H, C═CH ₂ ), 5.66-5.78 (m, 2H, CH ₂ —N), 6.12 (s _{, 1H, C = CH 2)} , 7.71-7.83 (m, 2H, Ar), 7.84-7.98 (m, 2H, Ar)

(Synthesis Example 6-1)
Benzyl 2,2-difluoro-3- (methacryloyloxy) pentanoate (a compound represented by the formula (M-21)) was synthesized.

After replacing the reactor sufficiently dried by vacuum heating with dry nitrogen, 25.54 g (0.1 mol) of 2,2-difluoro-3- (methacryloyloxy) pentanoic acid was placed in the reactor. Then, 11.13 g (0.11 mol) of triethylamine and 250 mL of methylene chloride were added. The mixture was cooled to 0 ° C. in an ice bath, and 17.06 g (0.1 mol) of benzyl chloroformate was added over 10 minutes while stirring. Thereafter, the temperature of the reactor was raised to room temperature, and after stirring for 2 hours, 300 g of a saturated aqueous sodium hydrogen carbonate solution was added with good stirring. Thereafter, the methylene chloride layer was separated, and the aqueous layer was extracted again with methylene chloride to obtain an extract. The extract was combined with the methylene chloride layer and washed with saturated brine, and then dried over sodium sulfate (desiccant). Thereafter, the desiccant was filtered off with a Buchner funnel, the organic solvent was distilled off, and the residue was purified by silica gel column chromatography. In this way, benzyl 2,2-difluoro-3- (methacryloyloxy) pentanoate (23.14 g (74% yield)) was obtained.

In addition, ¹ H-NMR data of benzyl 2,2-difluoro-3- (methacryloyloxy) pentanoate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 0.95 (t, 3H, CH ₂ —CH ₃ ), 1.75-1.89 (m, 2H, CH ₂ —CH ₃ ), 1.87 (s, _{3H, CH 3 -C), 5.24} (s, 2H, Ph-CH 2), 5.34-5.39 (m, 1H, CH-CF 2), 5.55 (s, 1H, C = _{CH 2), 6.06 (s,} 1H, C = CH 2), 7.33-7.42 (m, 5H, Ar)

(Synthesis Example 6-2)
The compound represented by the formula (M-21) could also be obtained by the following method.

Under a nitrogen atmosphere at 0 ° C., 1.60 g (14 mmol) of tert-butoxy potassium was added to a mixed solution of 140 mL of benzyl alcohol and 1200 mL of hexane in which 20.30 g (0.1 mol) of ethyl 2-bromo-2,2-difluoroacetate was dissolved. ) Was added. Thereafter, the mixture was stirred at 0 ° C. for 1 hour. After confirming the disappearance of the raw material by thin layer chromatography (TLC), 120 mL of concentrated hydrochloric acid was added to stop the reaction. Thereafter, each was washed twice with water and saturated brine, dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography to obtain 15.37 g of benzyl 2-bromo-2,2-difluoroacetate (yield 58%).

Under a nitrogen atmosphere, 100 mL of dehydrated THF was added to 3.79 g (58.0 mmol) of activated metal zinc. Thereafter, the mixture was heated until THF was refluxed. After warming, 15.37 g (58.0 mmol) of benzyl 2-bromo-2,2-difluoroacetate was added followed by 2.81 g (48.3 mmol) of propionaldehyde. Thereafter, the mixture was stirred for 15 minutes. After confirming the disappearance of the raw materials by thin layer chromatography (TLC), the reaction solution was cooled to room temperature, and an aqueous sodium hydrogen sulfate solution was added to stop the reaction. Thereafter, ethyl acetate was added to the reaction solution and extraction was performed three times. The obtained organic layer was washed once each with an aqueous sodium hydrogen carbonate solution, water and saturated brine, and dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography to obtain 9.32 g of benzyl 2,2-difluoro-3-hydroxypentanoate (yield 79%).

  Under nitrogen atmosphere, benzyl 2,2-difluoro-3-hydroxypentanoate 9.32 (38.2 mmol) and dehydrated THF 50 mL, triethylamine 4.63 g (45.8 mmol), dimethylaminopyridine 466 mg (3.82 mmol) at room temperature ) Was added. Thereafter, 4.39 g (42.0 mmol) of methacrylic acid chloride was added dropwise over 10 minutes. The mixture was then stirred for 2 hours. After confirming the disappearance of the raw material by thin layer chromatography (TLC), an aqueous sodium hydrogen carbonate solution was added to stop the reaction. Thereafter, ethyl acetate was added to the reaction solution to perform extraction three times. The obtained organic layer was washed once with water and saturated brine, and dried over anhydrous sodium sulfate. Then, the product obtained by distilling off the solvent under reduced pressure was purified by column chromatography to obtain 6.20 g of benzyl 2,2-difluoro-3- (methacryloyloxy) pentanoate (yield 52%).

（合成例８）
式（Ｍ−２３）で表される化合物の合成を、特開２００９−１３９９０９号公報の実施例１０を参照して合成した。

(Synthesis Example 7)
A compound represented by the formula (M-22) was synthesized with reference to Example 2 of JP2009-19199A.

(Synthesis Example 8)
The compound represented by the formula (M-23) was synthesized with reference to Example 10 of JP-A-2009-139909.

(Synthesis Example 9)
Methyl 2,2-difluoro-3- (methacryloyloxy) pentanoate (a compound represented by the following formula (M-24)) was synthesized.

  Under a nitrogen atmosphere, 100 g of ethyl 2,2-difluoro-3- (methacryloyloxy) pentanoate is dissolved in 1000 g of dehydrated methanol, and 0.1 g of N, N-dimethylaminopyridine (DMAP) is added thereto for 5 hours. It was heated to return. The reaction solution was evaporated, dissolved again in 1000 g of dehydrated methanol, and heated for 5 hours. The solvent of the reaction solution was distilled off, and the residue was dissolved in 300 g of n-hexane. The solution was filtered through 50 g of silica gel to remove DMAP, and 89.7 g of methyl 2,2-difluoro-3- (methacryloyloxy) pentanoate (M-24) was obtained (yield 95%).

In addition, ¹ H-NMR data of methyl 2,2-difluoro-3- (methacryloyloxy) pentanoate obtained in this example is shown below.
¹ H-NMR (CDCl ₃ ) δ: 1.00 (t, 3H, CH ₃ ), 1.70-1.90 (m, 2H, CH ₂ ), 1.95 (s, 3H, CH ₃ ), _{3.85 (s, 3H, CH 3} -O), 5.30-5.45 (m, 1H, CH-CF 2), 5.65 (s, 1H, C = CH 2), 6.17 ( s, 1H, C = CH ₂ )

(Preparation of polymer (A))
Resin (A) was prepared using the compound shown below.

(Synthesis Example A-1) 10.40 g (0.062 mol) of the compound (M-1), 2.01 g (0.015 mol) of the compound (M-11) and 13.74 g (0.062 mol) of the compound (M-7) ) Was dissolved in 60 g of 2-butanone, and a monomer solution in which 1.27 g of dimethyl 2,2′-azobis (2-methylpropionate) was further added was prepared. 3.84 g (0.015 mol) of the compound (M-5) was put into a 500 mL three-necked flask, 30 g of 2-butanone was added and dissolved, purged with nitrogen for 30 minutes, and then stirred at 80 ° C. while stirring the reaction kettle. The monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time.

After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or lower, and poured into 600 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was dispersed in methanol to form a slurry, washed, and then filtered off twice, followed by drying at 60 ° C. for 15 hours to obtain a white powder copolymer (yield 23 g, yield). Rate 76.7%). This copolymer has Mw of 5500 and Mw / Mn = 1.43, and as a result of ¹³ C-NMR analysis, compound (M-1), compound (M-5), and compound (M-11). The content (mol%) of repeating units derived from the compound (M-7) was 39.8: 8.6: 11.1: 40.5, respectively. This copolymer is referred to as “resin (A-1)”.

(Synthesis Examples A-2 to A-4)
Resins (A-2) to (A-4) were prepared in the same manner as in Synthesis Example 1 except that the compounding recipe of the compounds was shown in Table 2. Table 3 shows the physical properties of the resins (A-1) to (A-4).

(Preparation of polymer (C))
A polymer (C) was prepared using the compounds shown in Table 1.

(Synthesis Example C-1)
Compound (M-16) (5.0 g, 0.022 mol) is dissolved in 2-butanone (10 g), and dimethyl 2,2′-azobis (2-methylpropionate) (0.25 g) is added to a 200 mL three-necked flask. After purging with nitrogen for 30 minutes, the reaction kettle was heated to 80 ° C. with stirring. The start of heating was set as the polymerization start time, and the polymerization reaction was carried out for 4 hours. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or lower by water cooling. The polymerization solution was concentrated under reduced pressure using an evaporator until the weight of the polymerization solution became 7.5 g. Thereafter, the concentrated solution was poured into a mixed solution of 50 g of methanol and 50 g of water to precipitate a slime-like white solid. The liquid part was removed by decantation, and a mixed solution of 50 g of methanol and 50 g of water was added again to wash the slime-like white solid twice. The collected solid was vacuum-dried at 60 degrees for 15 hours to obtain 3.1 g of white powder (yield 62%). Mw was 7000, Mw / Mn was 1.48, and as a result of ¹³ C-NMR analysis, the content of the repeating unit derived from the compound (M-16) was 100 mol%. This copolymer is referred to as “polymer (C-1)”.

(Synthesis Examples C-2 to C-21)
Polymers (C-3) to (C-21) were prepared in the same manner as in Synthesis Example C-2 except that the compounding recipe of the compounds was shown in Table 4. Table 3 shows physical property values of the polymers (C-1) to (C-21).

(Acid generator (B)) Hereinafter, the acid generator (B) used by the Example and the comparative example is shown to a table | surface.

(Acid diffusion control agent (D))
Hereinafter, the acid diffusion controller (D) used in Examples and Comparative Examples is shown in the table.

(Solvent (E))
Hereinafter, the solvent (E) used in Examples and Comparative Examples is shown.
(E-1): Propylene glycol monomethyl ether acetate,
(E-2): Cyclohexanone.

  In addition, γ-butyrolactone was used as an additive.

Example 1
100 parts of the polymer (A-1) prepared in Synthesis Example A1, 5 parts of the fluoropolymer (C-1) prepared in Synthesis Example C-1, 9.9 parts of the acid generator (B-1), acid Composition of radiation sensitive resin composition by mixing 1.5 parts of diffusion control agent (D-1), 100 parts of γ-butyrolactone as an additive, 1500 parts of solvent (E-1), and 650 parts of (E-2). A product solution was prepared.

(Examples 2 to 21, Comparative Examples 1 to 7)
A composition solution of each radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that the formulation shown in Table 7 was used.

  The evaluation results are shown in Table 8.

  The radiation-sensitive resin composition of the present invention can be suitably used as a chemically amplified resist for manufacturing semiconductor devices, particularly a resist for immersion exposure.

Claims (9)

A polymer (A) having a fluorine atom content of less than 5% by mass having an acid dissociable group, an acid generator (B) that generates an acid upon irradiation with radiation, and a functional group represented by the following general formula (x) And a polymer having a fluorine atom content of 5% by mass or more (C),
The polymer (A) does not have a structural unit represented by the following general formula (a-1) ,
The radiation sensitive resin composition in which the polymer (C) has a repeating unit represented by the following general formula (c-2) .

[In general formula (x), A represents an oxygen atom (excluding those directly connected to an aromatic ring, a carbonyl group or a sulfonyl group), an imino group, or —CO—O— * ( “*” represents R ¹⁾ . The bond to be bonded is shown.) R ¹ is an alkali-dissociable group dissociates by the action of an alkali developer, when A is an oxygen atom or an imino group, R ¹ represents a group represented by the following general formula (R1-1), A is In the case of —CO—O— *, R ¹ represents a group represented by any one of the following general formulas (1) to (3). ]

[In General Formula (R1-1), R ⁸ represents a C1-C10 fluorine-substituted hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom. ]

[In the general formulas (1) and (2), R ¹⁰ represents a halogen atom or an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an acyl group, or an acyloxy group. . m ₁ represents an integer of 0 to 5, and m ₂ represents an integer of 0 to 4. In General Formula (3), R ¹¹ and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R ¹¹ and R ¹² may be bonded to each other to form an alicyclic structure having 4 to 20 carbon atoms together with the carbon atom to which each is bonded. ]

[In General Formula (a-1), R ^a is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ^b is a divalent linking group, and R ^c is a ring thereof. A cyclic group containing —SO ₂ — in the skeleton is shown. ]

[In General Formula (c-2), R represents a hydrogen atom, a methyl group or a trifluoromethyl group. G represents a single bond, an oxygen atom, a sulfur atom, —CO—O—, —SO ₂ —O—NH— , —CO —NH— or —O—CO—NH—. R ⁴ is a fluorine-substituted chain hydrocarbon group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or a fluorine-substituted cyclic group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. A hydrocarbon group is shown. ] The radiation sensitive resin composition according to claim 1, wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1).

[In General Formula (c-1), R ¹ and A have the same meaning as in the description of General Formula (x). R ² represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 10 carbon atoms, or a cyclic hydrocarbon group having 4 to 20 carbon atoms. X ¹ represents a single bond, a difluoromethylene group or a linear or branched perfluoroalkylene group having 2 to 20 carbon atoms. R ³ represents an (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O— or —CO—NH— at the terminal on the R ² side. Also includes a structure in which is bound. E represents an oxygen atom, —CO—O— * or —CO—NH— * (“*” represents a bond bonded to R ³ ), and R represents a hydrogen atom, a methyl group or a trifluoromethyl group. n shows the integer of 1-3. However, when n is 2 or 3, R ¹ , R ² , X ¹ and A are independent of each other. ] The radiation sensitive resin composition according to claim 1, wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a).

[In General Formula (c-1a), R ¹ and A have the same meaning as in the description of General Formula (x), and R, R ² , R ³ , X ¹ and n are the same as in the description of General Formula (c-1). It is synonymous. ] The radiation sensitive resin composition according to claim 1, wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a-1).

[In the general formula (c-1a-1), R, R ² , R ³ , X ¹ and n are as defined in the general formula (c-1). R ⁸ has the same meaning as in the description of General Formula (R1-1) . ] The radiation sensitive resin composition according to claim 1, wherein the polymer (C) is a polymer having a repeating unit represented by the following general formula (c-1a-2).

[In the general formula (c-1a-2), R, R ² and X ¹ are as defined in the general formula (c-1). R ³¹ represents a methylene group, a divalent cyclic hydrocarbon group in the alkylene group or from 4 to 20 carbon atoms linear or branched having 2 to 10 carbon atoms, an oxygen atom at the terminal of R ² side, a sulfur atom, A structure in which an imino group, a carbonyl group, —CO—O— or —CO—NH— is bonded is also included. R ⁹ represents a group represented by any one of the general formulas (1) to (3) . ] The radiation sensitive resin composition of any one of Claims 1-5 which contain 0.1-20 mass parts of said polymers (C) with respect to 100 mass parts of said polymers (A). The radiation-sensitive resin composition according to any one of claims 1 to 6 , which is a radiation-sensitive resin composition for immersion exposure. A film forming step (1) for forming a resist film comprising the radiation-sensitive resin composition according to any one of claims 1 to 7 , on a substrate;
An exposure step (2) of irradiating the resist film with radiation through a mask pattern to expose the resist film;
And a developing step (3) for developing the exposed resist film to form a resist pattern. The exposure step (2) comprises placing an immersion exposure liquid on the resist film formed in the film formation step (1), and exposing the resist film through the immersion exposure liquid. 9. The resist pattern forming method according to 8 .