JP2006131739A - Manufacturing process of resist polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process of a resist polymer which exhibits high sensitivity and resolution, when used in a resist composition for DUV excimer laser lithography, electron ray lithography or the like and an excellent storage stability, when formulated in a resist composition, a resist composition containing the resist polymer obtained by the process and a method of patterning using the resist composition. <P>SOLUTION: The manufacturing process relates to the manufacture of a resist polymer containing constitutional unit (A1) expressed by formula (1) and having a partial charge of at least one hydrogen atom of the methyl group of group A of ≥0.150. The manufacturing process of the resist polymer comprises adding the polymer solution obtained by solution polymerization to at least one kind of organic medium selected from hydrocarbons, halogenated hydrocarbons, nitro compounds, nitriles, ethers, ketones, esters and carbonates and precipitating or re-precipitating the polymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a resist polymer and a resist composition, and more particularly to a chemically amplified resist composition suitable for fine processing using an excimer laser or an electron beam.

  In recent years, in the field of microfabrication in the manufacture of semiconductor elements and liquid crystal elements, miniaturization has rapidly progressed due to advances in lithography technology. As a method for miniaturization, generally, a shorter wavelength of irradiation light is used. Specifically, from conventional ultraviolet rays typified by g-line (wavelength: 438 nm) and i-line (wavelength: 365 nm) to DUV ( The irradiation light is changing to Deep Ultra Violet.

At present, KrF excimer laser (wavelength: 248 nm) lithography technology has been introduced to the market, and ArF excimer laser (wavelength: 193 nm) lithography technology and F ₂ excimer laser (wavelength: 157 nm) lithography technology for further shortening of wavelength have been studied. Has been. Recently, these immersion lithography techniques have also been studied. In addition, an electron beam lithography technique has been energetically studied as a slightly different type of lithography technique.

  As a high-resolution resist for such short-wavelength irradiation light or electron beam, a “chemically amplified resist” containing a photoacid generator has been proposed. At present, improvements and development of this chemically amplified resist are energetically active. It is being advanced.

  For example, as a resist resin used in ArF excimer laser lithography, an acrylic resin that is transparent with respect to light having a wavelength of 193 nm has attracted attention. Among such acrylic resins, a polymer having an acetal structure that is eliminated by the action of an acid is attracting attention because of its excellent sensitivity or resolution when used as a resist composition.

  For example, Patent Document 1 discloses a photosensitive resin obtained by using a monomer having an acetal structure that is synthesized from a carboxylic acid and vinyl ether and is eliminated by the action of an acid.

  However, when the partial charge of hydrogen atoms in the acetal structure that is eliminated by the action of acid is large, when recovering the polymer by precipitation or reprecipitation from the polymer solution obtained by the solution polymerization method, ligroin as a recovery solvent When a solvent having a small solubility parameter is used, a large amount of oligomer components remain. Therefore, when this resin is used as a resist composition, the resolution and pattern shape of the resist may be adversely affected.

On the other hand, when a solvent having a large solubility parameter such as methanol or water is used as the recovery solvent, the acetal structure may be eliminated and carboxylic acid may be generated in the polymer. When this polymer is used as a resist composition, during the preservation of the resist composition, the carboxylic acid present in the polymer promotes the elimination reaction of the acid-eliminable group and changes the sensitivity. May cause deterioration.
Japanese Patent No. 2907144

  The present invention produces a resist polymer having high sensitivity and high resolution when used as a resist composition in DUV excimer laser lithography or electron beam lithography, and having excellent storage stability when used as a resist composition. It is an object of the present invention to provide a resist composition containing a resist polymer obtained by this method, and a pattern production method using this resist composition.

The present inventors have intensively studied to achieve the above object, and in particular, pay attention to the constituent unit of the resist polymer and the recovery solvent when recovering the polymer from the resist polymer solution obtained by the solution polymerization method. As a result, a specific recovery solvent, a method for producing a resist polymer containing a structural unit having a specific acid-eliminable group, and using a resist polymer obtained by this production method for a resist composition The present inventors have found that the composition has excellent storage stability when used as a resist composition, and has completed the present invention.
That is, the present invention
[1] The following formula (1)

(In the formula (1), R ¹¹ represents a hydrogen atom or a methyl group. Z represents a single bond, a divalent to tetravalent group derived from an alkane, or a divalent to tetravalent alicyclic carbon atom having 4 to 20 carbon atoms. Represents a hydrogen group, —C (═O) —, —S (═O) ₂ —, or a combination thereof, or a bivalent to tetravalent group, n represents an integer of 1 to 3, A represents a methyl group, R ¹⁴ represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 5 carbon atoms.
And at least one hydrogen atom of the methyl group of the group A is a method for producing a resist polymer containing a structural unit (A1) having a partial charge of 0.150 or more, which is obtained by a solution polymerization method. The resulting polymer solution is precipitated or re-precipitated by adding it to at least one organic solvent selected from hydrocarbons, halogenated hydrocarbons, nitro compounds, nitriles, ethers, ketones, esters, and carbonates. A method for producing a resist polymer, wherein:

[2] The solubility parameter according to the Fedors method of the organic solvent used as the precipitation or reprecipitation solvent is 7.0 (cal / cm ³ ) ^{1/2 to} 14.0 (cal / cm ³ ) ^1/2 [ 14.3 MPa ^{1/2 to} 28.6 MPa ^1/2 ] [1] method for producing a resist polymer according to the present invention;

[3] The method according to [1] or [2], further comprising a structural unit (B) having a lactone skeleton that is at least one selected from the group consisting of the following formulas (4-1) to (4-5): Method for producing resist polymer;

(In the above formula, R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁵¹ , R ⁶¹ and R ⁷¹ each independently represents a hydrogen atom or a methyl group, and R ⁴⁰¹ , R ⁴⁰² , R ²⁰¹ , R ²⁰² , R ^{203, R 204, R 91,} R 92, R 93, R 94, a 1, a 2, a 3, a 4 are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy groups Represents a carboxy group or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, and X ⁴¹ , X ⁴² , X ⁴³ and X ⁴⁴ are each a hydroxy group, a carboxy group, or an acyl having 1 to 6 carbon atoms as a substituent. A carbon number which may have at least one group selected from the group consisting of a group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, a cyano group and an amino group 1-6 linear or branched alkyl groups, hydroxy , A carboxy group, an acyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or an amino group, n41, n42, n43, n44 .n41 is an integer of 0~4, n42, n43, when n44 is 2 or ^{more, X 41, X 642, X} 43, X 44 comprises also each have a plurality of different groups .Y ^11, Y ²¹ and Y ³¹ each independently represent —CH ₂ — or —CO—O—, of which at least one represents —CO—O—, i represents 0 or 1, and m and m1 represent 1 or 2 R ⁴⁰¹ and R ⁴⁰² (when i = 1), R ⁹¹ and R ⁹² (when m1 = 1) are taken together to form a methylene chain having 2 to 6 carbon atoms [— (CH ₂ ) _j − (J represents an integer of 2 to 6)] or a methylene chain having 1 to 6 carbon atoms including —O—, —S—, and —NH— [— (C _{2) k} - (k may form a representative) an integer of 1-6, in the case of R ⁹¹ s or R ⁹² together (m1 = 2), and A ¹ and A ^2, A ³ and A ⁴ Together may contain —O—, —S—, —NH—, methylene chain having 1 to 6 carbon atoms [— (CH ₂ ) ₁ — (l represents an integer of 1 to 6)] Or -O-, -S-, or -NH- may be formed.)

[4] Further, in any one of the above [1] to [3], which further comprises a structural unit (C) having a hydrophilic group that is at least one selected from the group consisting of the following formulas (5-1) to (5-7) A method for producing a resist polymer according to any one of the above;

(In the above formula, R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ each independently represents a hydrogen atom or a methyl group, and R ⁵⁰¹ , R ⁵⁰² , R ⁵⁰³ , R ⁵⁰⁶ are each Independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁵⁰⁴ and R ⁵⁰⁵ each independently represents an alkyl group having 1 to 3 carbon atoms, and R ⁵³¹ , R ⁵³² , R ⁵³³ , R ⁵³⁴ , R ⁵³⁵ , R ⁵³⁶ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, R ⁵⁷¹ and R ⁵⁷² are bridged cyclic hydrocarbon groups having 4 to 16 carbon atoms, or 4 to 4 carbon atoms A straight chain or branched alkyl group having 1 to 6 carbon atoms having 16 bridged cyclic hydrocarbon groups, and a bridged cyclic carbonization having 4 to 16 carbon atoms together with the carbon atom to which R ⁵⁷¹ and R ⁵⁷² are bonded A hydrogen group may be formed, and W ¹ , W ² , and W ³ are each independently —O—, —S—, -NH- or a methylene chain having a chain length of 1 to 6 [-(CH ₂ ) _t- (t represents an integer of 1 to 6)], X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , X ⁵⁶ and X ⁵⁷ each independently represent —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms as a substituent. of carboxy group and a linear or branched alkyl group having at least one carbon atoms which may have a group 1 to 6 chosen from the group consisting of amino _{groups, -C (CF 3) 2 -OH} , hydroxy group , A cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxy group or an amino group esterified with an alcohol having 1 to 6 carbon atoms, n51, n52, n53 , N54, n55, and n56 represent an integer of 1 to 4. q1, q2 represents 0 or 1. Incidentally, n51, n52, n53, n54 , n55, when n56 is 2 or ^{more, X 51, X 52, X} 53, X 54, X 55, X 56 are each It includes having a plurality of different groups.
Here, the alkyl group of R ⁵⁷¹ and R ⁵⁷² and the bridged cyclic hydrocarbon group may have a linear or branched alkyl group having 1 to 6 carbon atoms, and may be a hydroxy group, a carboxy group, or a carbon number of 2 It may have a carboxy group esterified with an acyl group of -6 or an alcohol having 1 to 6 carbon atoms. )

[5] A resist polymer produced by the method according to any one of [1] to [4];

[6] A resist composition containing the resist polymer according to [5];

[7] A pattern manufacturing method including a step of applying the resist composition according to [6] onto a substrate to be processed, a step of exposing with light having a wavelength of 250 nm or less, and a step of developing using a developer. ;
About.

  Since the resist polymer and resist composition of the present invention have high sensitivity and high resolution and are excellent in storage stability when used as a resist composition, a highly accurate fine resist pattern can be produced. Therefore, the resist polymer and resist composition of the present invention can be suitably used for DUV excimer laser lithography, these immersion lithography and electron beam lithography, particularly ArF excimer laser lithography, and this immersion lithography.

The resist polymer of the present invention will be described.
The resist polymer of the present invention comprises at least a structural unit (A1) represented by the above formula (1) and having at least one hydrogen atom of a methyl group represented by the group A having a partial charge of 0.150 or more. (Hereinafter referred to as “structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more”). Here, the “acid leaving group” means a group that decomposes or leaves by the action of an acid.

  The partial charge of each atom can generally be calculated by known quantum mechanical, empirical or semi-empirical methods. Among them, a calculation method using a semi-empirical molecular orbital method (MO method) is preferable, and MOPAC is particularly preferable. More specifically, using the molecular modeling software “CAChe WorkSystm Pro Version 6.01” manufactured by Fujitsu, the most stabilized structure of the molecule was first calculated using MOPAC using the PM5 method, and then the methyl group of the group A of interest. It is preferable to obtain partial charges of the three hydrogen atoms. The partial charge is expressed in units of electronic charge and is usually in the range of −1 to +1.

  In addition, the structural unit (A1) having an acid-eliminable group having a partial charge of 0.150 or more according to the present invention has a higher acid-eliminating ability than an acid-eliminable group described later, so When the polymer containing (A1) is used as a resist composition, it has high sensitivity, so that the throughput of semiconductor manufacturing can be improved.

In addition to the structural unit (A) having an acid leaving group, the resist polymer of the present invention has a structural unit (B) having a lactone skeleton and / or a structural unit (C) having a hydrophilic group. It is preferable to contain. Here, the “hydrophilic group” refers to —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group, an amino group, and an acyl group having 1 to 6 carbon atoms. And a carboxy group esterified with an alcohol having 1 to 6 carbon atoms.

  Furthermore, the resist polymer of the present invention comprises an acid leaving group represented by the above formula (1) other than the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more. May be contained (hereinafter simply referred to as “structural unit (A2) having an acid-eliminable group”).

  The resist polymer of the present invention comprises an acid detachment other than the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more and the structural unit (A2) having an acid leaving group. A structural unit (D) having a releasing group (hereinafter referred to as “structural unit (D) having other acid-eliminable group”) may be contained.

  In the resist polymer of the present invention, the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more, the structural unit (A2) having an acid leaving group, and other acid eliminations. The total ratio with the structural unit (D) having a sex group is preferably 30 mol% or more, and more preferably 35 mol% or more in total from the viewpoint of sensitivity and resolution. Further, in the resist polymer of the present invention, the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more, the structural unit (A2) having an acid leaving group, and other acids The total ratio with the structural unit (D) having a leaving group is preferably 60 mol% or less, more preferably 55 mol% or less, and more preferably 50 mol% in terms of adhesion to the substrate surface or the like. The following is more preferable.

  The structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more, the structural unit (A2) having an acid leaving group, and other acid elimination in the resist polymer of the present invention The ratio with the structural unit (D) having a functional group is preferably in the range of 5 mol% / 95 mol% to 100 mol% / 0 mol%, from the viewpoint of sensitivity and resolution, and is preferably 10 mol% / 90 mol% to 100 mol%. The range of mol% / 0 mol% is more preferable.

  The ratio of the structural unit (B) having a lactone skeleton in the resist polymer of the present invention is preferably 30 mol% or more in total, more preferably 35 mol% or more, from the viewpoint of adhesion to the substrate surface or the like. . In addition, the ratio of the structural unit (B) having a lactone skeleton in the resist polymer of the present invention is preferably 60 mol% or less, more preferably 55 mol% or less in total from the viewpoint of sensitivity and resolution. The mol% or less is more preferable.

  The ratio of the structural unit (C) having a hydrophilic group in the resist polymer of the present invention is preferably 5 to 30 mol% or more in total, and 10 to 25 mol% or more in terms of pattern shape stability. More preferred.

  When the structural unit (C) having a hydrophilic group has a protecting group that is eliminated by an acid, the sensitivity is more excellent.

  The structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more and the structural unit (A2) having an acid leaving group will be described.

  As the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more and the structural unit (A2) having an acid leaving group, the sensitivity and / or resolution required for the resist is high. From the point, it is a structural unit represented by the formula (1).

  N in the formula (1) is preferably n = 1 or 2 and more preferably n = 1 from the viewpoint of high polymerizability.

Z in Formula (1) is a single bond, a divalent to tetravalent group derived from an alkane, a divalent to tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, -C (= O)-, —S (═O) ₂ — or a combination of these groups represents a divalent to tetravalent group. Examples of the divalent to tetravalent group derived from alkane include divalent alkylene, trivalent alkanetriyl, and tetravalent alkanetetrayl, and alkylene such as methylene, ethylene, and propylene is preferable. Examples of the divalent to tetravalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include divalent to tetravalent groups derived from monocyclic alicyclic hydrocarbons such as cyclobutane, cyclopentane, and cyclohexane, camphor ring, and adamantane 2 to 4 valents derived from polycyclic or bridged cyclic hydrocarbons such as a ring, norbornane ring, pinane ring, bicyclo [2.2.2] octane ring, tetracyclododecane ring, tricyclodecane ring and decahydronaphthalene ring Which may have a bond such as —O— or —S—, or may have a linear or branched alkyl group having 1 to 4 carbon atoms as a substituent. good. Z is preferably —C (═O) — or —S (═O) ₂ — because of its high solubility in organic solvents, and 2 to 4 having 20 to 20 carbon atoms from the point of high dry etching resistance. A divalent to tetravalent group in which a tetravalent alicyclic hydrocarbon group is combined with —C (═O) — and / or —S (═O) ₂ — is preferable. Examples thereof include divalent to tetravalent groups represented by 1) to (Z1-108). In addition, the bond on the left side of each structural formula is bonded to the quaternary carbon of the polymer main chain, and the bond on the right side is bonded to the acid leaving group.

R ¹⁴ in the formula (1) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms from the viewpoint of high solubility in an organic solvent, and R ¹⁴ is high in dry etching resistance. A monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof is preferable, and examples thereof include structures represented by the following formulas (J1-1) to (J1-74).

  Specific examples of the monomer that becomes a structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more by polymerization are specifically represented by the following formulas (8-1) to (8-22). Monomer to be used. In formulas (8-1) to (8-22), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of dry etching resistance, monomers represented by the above formulas (8-5) to (8-18) and the above formula (8-23), and optical isomers thereof are more preferable. From the viewpoint of line edge roughness, monomers represented by the above formulas (8-1) to (8-4) are more preferable.

As the structural unit (A2) having an acid leaving group, Z in the above formula (1) is —C (═O) —, —S (═O) ₂ —, or the above formula (Z1-1). A combination of divalent to tetravalent groups represented by (Z1-108), wherein R ¹⁴ is any one of formulas (J1-1) to (J1-74). Among them, examples include structures other than the structural unit (A1) having an acid leaving group having a partial charge of 0.150 or more, and examples thereof include the following formulas (8-103) to (8-188). In formulas (8-103) to (8-188), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of dry etching resistance, the monomers represented by the above formulas (8-110) to (8-137), the above formulas (8-174) to (8-188), and their optics Isomers are more preferable, and from the viewpoint of line edge roughness, monomers represented by the above formulas (8-103) to (8-109) and the above formulas (8-142) to (8-173) are more preferable. preferable.

Next, the structural unit (B) having a lactone skeleton will be described.
The structural unit having a lactone skeleton is a structural unit represented by the above formulas (4-1) to (4-5) from the viewpoint of sensitivity or dry etching resistance.
In these formulas, the linear or branched alkyl group having 1 to 6 carbon atoms includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n- Pentyl group, neo-pentyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 1,1-dimethylbutyl group, 2,2-dimethylbutyl group, n-hexyl group, 1-methylpentyl group , 2-methylpentyl group, 3-methylpentyl group and the like.
N41, n42, n43 and n44 in the formulas (4-1) to (4-4) are preferably 0 from the viewpoint of high dry etching resistance.
M in Formula (4-1) is preferably 1 from the viewpoint of sensitivity and resolution.
A ¹ and A ² in the formula (4-2), A ³ and A ⁴ in the formula (4-3), from the viewpoint high dry etching resistance is -CH together ₂ -, - CH ₂ CH ₂ — is preferable, and from the viewpoint of high solubility in an organic solvent, it is preferable to form —O— together.
R ²⁰¹ and R ^{202 in} the formula (4-2) and R ²⁰³ and R ²⁰⁴ in the formula (4-3) are each independently a hydrogen atom, a methyl group, from the viewpoint of high solubility in an organic solvent, It is preferably an ethyl group or an isopropyl group.
R ⁵¹ , R ⁶¹ , and R ^{71 in} formula (4-4) are preferably a hydrogen atom from the viewpoint of high solubility in an organic solvent.
In formula (4-4), Y ¹¹ , Y ²¹ , and Y ³¹ are each one of —CO—O— and the other two are —CH ₂ — from the viewpoint of high adhesion to the substrate surface and the like. It is preferable.
In formula (4-5), R ⁹¹ , R ⁹² , R ⁹³ , and R ⁹⁴ are each independently preferably a hydrogen atom or a methyl group from the viewpoint of high solubility in an organic solvent.
M1 in Formula (4-5) is preferably 1 from the viewpoint of sensitivity and resolution.

  These structural units (B) having a lactone skeleton may be one type or two or more types.

  Specific examples of the monomer that is polymerized to become the structural unit (B) having a lactone skeleton include monomers represented by the following formulas (10-1) to (10-26). In formulas (10-1) to (10-26), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of sensitivity, the monomers represented by the above formulas (10-1) to (10-3) and the above formula (10-5), and geometric isomers and optical isomers thereof are more preferable. From the point of dry etching resistance, the above formulas (10-7), (10-9), (10-10), (10-12), (10-14), (10-24) to (10-26) ), And geometric isomers and optical isomers thereof are more preferable. From the viewpoint of solubility in a resist solvent, the above formulas (10-8), (10-13), and Monomers represented by (10-16) to (10-23), and geometric isomers and optical isomers thereof are more preferable.

Next, the structural unit (C) having a hydrophilic group will be described.
The structural unit (C) having a hydrophilic group is a structural unit represented by the above formulas (5-1) to (5-7) from the viewpoint of high dry etching resistance required for a resist.
R ⁵⁰¹ in the formula (5-1), R ⁵⁰² in the formula (5-3), R ⁵⁰³ in the formula (5-4), R506 in formula (5-6), from the viewpoint of sensitivity and resolution Is preferably a methyl group, an ethyl group, or an isopropyl group, and is preferably a hydrogen atom from the viewpoint of good solubility in an organic solvent.
In formulas (5-1) to (5-6), n51, n52, n53, n54, n55, and n56 are preferably 1 from the viewpoint of high dry etching resistance.
X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , and X ⁵⁶ in formulas (5-1) to (5-6) are —C (CF ₃ ) ₂ —OH, It is preferably a hydroxy group, a cyano group, or a methoxy group. X5 ⁷ in formula (5-7) represents —CH ₂ —C (CF 3) ₂ —OH, —CH ₂ —OH group, —CH ₂ —CN group, —CH ₂ —, from the viewpoint of good pattern shape. An O—CH ₃ group and a — (CH ₂ ) 2 —O—CH ₃ group are preferred.
W ¹ and W ^{2 in} formula (5-3) and W ³ in formula (5-6) are preferably —CH ₂ — and —CH ₂ CH ₂ — from the viewpoint of high dry etching resistance.
R ⁵³¹ , R ⁵³² , R ⁵³³ , and R ⁵³⁴ in formula (5-3) and R535 and R536 in formula (5-6) are each independently hydrogen from the viewpoint of high solubility in an organic solvent. An atom, a methyl group, an ethyl group, or an isopropyl group is preferable.
Q1 in the formula (5-3) and q2 in the formula (5-6) are preferably 1 from the viewpoint of high dry etching resistance, and 0 from the viewpoint of good solubility in an organic solvent. It is preferable that
R1 in formula (5-4) is preferably 1 from the viewpoint of high dry etching resistance, and preferably 0 from the viewpoint of good solubility in an organic solvent.
In the formula (5-5), R504 and R505 are preferably each independently a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution.
R ⁵⁷¹ and R ^{572 in} formula (5-7) are bridged cyclic hydrocarbon groups having 4 to 16 carbon atoms, together with the carbon atom to which R ⁵⁷¹ and R ⁵⁷² are bonded, from the viewpoint of high dry etching resistance. The structure which forms is preferable. From the viewpoint of excellent heat resistance and stability, R ⁵⁷¹ and R ⁵⁷² are camphor ring, adamantane ring, norbornane ring, pinane ring, bicyclo [2.2.2] octane ring, tetracyclododecane ring, tricyclodecane ring. It preferably has a decahydronaphthalene ring.
In the formulas (5-1) to (5-6), the position substituted with X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , X ⁵⁶ may be any position in the cyclic structure. .
The structural unit (C) having a hydrophilic group can be used alone or in combination of two or more as necessary.

  Specific examples of the monomer that is polymerized and becomes the structural unit (C) having a hydrophilic group include monomers represented by the following formulas (13-1) to (13-103). In formulas (13-1) to (13-103), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of good solubility in a resist solvent, monomers represented by the above formulas (13-1) to (13-4), and the above formulas (13-9) to (13-13) Monomers represented by the above formulas (13-21) to (13-24), monomers represented by the above formulas (13-33) to (13-36), Monomers represented by formulas (13-42) to (13-46), monomers represented by formulas (13-53) to (13-59), and formulas (13-78) to (13) 13-79), the above formulas (13-82) to (13-83), the above formulas (13-88) to (13-89) Monomers, monomers represented by the above formulas (13-94) to (13-97), monomers represented by the above formula (13-100), geometric isomers thereof, and these of From the viewpoint of more preferable isomers and high dry etching resistance, monomers represented by the above formulas (13-37) to (13-42), and the above formulas (13-60) to (13- 77), monomers represented by the above formulas (13-84) to (13-85), monomers represented by the above formulas (13-90) to (13-91) , Monomers represented by the above formula (13-99), monomers represented by the above formulas (13-101) to (13-103), and geometric isomers and optical isomers thereof More preferably, from the viewpoint of sensitivity and resolution, the monomers represented by the above formulas (13-5) to (13-8), and the above formulas (13-17) to (13-20) Monomers represented by the above formulas (13-29) to (13-32), and the above formulas (13-49) to (13) 52), monomers represented by the above formulas (13-62) to (13-63), monomers represented by the above formulas (13-68) to (13-69) Body, monomers represented by the above formulas (13-74) to (13-75), monomers represented by the above formulas (13-80) to (13-81), and the above formulas (13-86) ) To (13-87), monomers represented by the above formulas (13-92) to (13-93), geometric isomers thereof, and optical isomers thereof. More preferred.

The structural unit (D) having another acid leaving group will be described.
As other structural units having an acid-eliminable group, the following formulas (3-1-1) to (3-) are used because they have high dry etching resistance required for resists and / or excellent line edge roughness. The structural unit represented by 8-1) is preferable.

(Wherein R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ , R ³⁸ represent a hydrogen atom or a methyl group, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ Represents an alkyl group having 1 to 3 carbon atoms, X ¹ , X ² , X ³ , X ⁴ , X ⁵ and X ⁶ represent a linear or branched alkyl group having 1 to ⁶ carbon atoms, and n1, n2, n3 , N4, n5, n6 represent an integer of 0 to ^{4. When} n1, n2, n3, n4, n5, n6 is 2 or more, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , Including a plurality of different groups as X ^6. R ³³¹ , R ³³² , R ³³³ , R ³³⁴ , R ³⁵¹ , R ³⁵² , R ³⁵³ , R ³⁵⁴ , R ³⁶¹ , R ³⁶² , R ³⁶³ , R ³⁶⁴ are each Independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and Z ¹ , Z ² , Z ³ , Z ⁴ , Z ⁵ and Z ⁶ are each independently —O—, —S—, — NH- or chain length 6 methylene chain _{[- (CH 2) u1 -} (u1 represents an integer of 1 to 6)] represents, q, q3, q4 is 0 or 1, r is an integer of 0 to 2.
In formula (3-5-1), R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ are each independently a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a straight chain having 1 to 4 carbon atoms. Or a branched alkyl group, and at least one of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ is the alicyclic hydrocarbon group or a derivative thereof, or any one of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ Two of them are bonded to each other to form an alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atom to which each is bonded, and is involved in bonding among R ³⁵⁵ , R ³⁵⁶ , and R ^357. The remaining one represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof. Wherein (3-6-1), R ³⁶⁷ is a monovalent alicyclic hydrocarbon group or its derivative, or a linear or branched alkyl group having 1 to 4 carbon atoms having 4 to 20 carbon atoms, R ³⁶⁵ and R ³⁶⁶ both represent a hydrogen atom, or R ³⁶⁵ and R ³⁶⁷ or R ³⁶⁶ and R ³⁶⁷ are bonded to each other, and together with the carbon atoms to which they are bonded, each has 4 to 20 carbon atoms An alicyclic hydrocarbon group or a derivative thereof is formed, and the remaining one of R ³⁶⁵ and R ³⁶⁶ not participating in the bond represents a hydrogen atom.
In the formula (3-7-1), R ³⁷³ represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, R ³⁷¹ and R ³⁷² both represent a hydrogen atom, or two of R ³⁷¹ and R ³⁷³ or R ³⁷² and R ³⁷³ are bonded to each other, and together with the carbon atom to which each is bonded, they have 4 to 20 carbon atoms. The remaining one of R ³⁷¹ and R ³⁷² that formed an alicyclic hydrocarbon group or a derivative thereof and did not participate in bonding represents a hydrogen atom.
In formula (3-8-1), R ³⁸¹ , R ³⁸² and R ³⁸³ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms. )

R ¹ in formula (3-1-1), R ² and R ^{3 in} formula (3-2-1), R ⁴ in formula (3-3-1), formula (3-4-1) R ⁵ therein is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution.
N1, n2, n3, n4, n5, and n6 in formulas (3-1-1) to (3-6-1) are preferably 0 from the viewpoint of high dry etching resistance.
Z ¹ and Z ^{2 in} formula (3-3-1), Z ³ and Z ^{4 in} formula (3-5-1), Z ⁵ and Z ^{6 in} formula (3-6-1) are dry From the viewpoint of high etching resistance, each is preferably independently —CH ₂ — or —CH ₂ CH ₂ —.
R ³³¹ , R ³³² , R ³³³ , and R ³³⁴ in formula (3-3-1), R ³⁵¹ , R ³⁵² , R ³⁵³ , and R ³⁵⁴ in formula (3-5-1), formula (3- R ³⁶¹ , R ³⁶² , R ³⁶³ , and R ^{364 in} 6-1) are each independently a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group because of their high solubility in organic solvents. preferable.
Q in Formula (3-3-1), q3 in Formula (3-5-1), and q4 in Formula (3-6-1) must be 1 in terms of high dry etching resistance. Preferably, 0 is preferable from the viewpoint of good solubility in an organic solvent.
R in the formula (3-4-1) is preferably 1 in terms of high dry etching resistance, and preferably 0 in terms of good solubility in organic solvents.

-C (R ³⁵⁵ ) (R ³⁵⁶ ) (R ³⁵⁷ ) in the formula (3-5-1) is represented by the following formulas (K-1) to (K-6) in that the line edge roughness is excellent. The structure represented is preferable, and the structure represented by the following formulas (K-7) to (K-17) is preferable in that the dry etching resistance is high.

-C (R ³⁶⁵ ) (R ³⁶⁶ ) -O-R ³⁶⁷ in the formula (3-6-1) is the following formula (J-1) to (J-13) in that it has excellent line edge roughness. In terms of high dry etching resistance, structures represented by the following formulas (J-14) to (J-28) are preferable.

-C (R ³⁷¹ ) (R ³⁷² ) -O-R ³⁷³ in formula (3-7-1) is the above formula (J-1) to (J-13) in that it is excellent in line edge roughness. In terms of high dry etching resistance, the structures represented by the above formulas (J-14) to (J-28) are preferable.

  The structural unit (D) having another acid-eliminable group can be used alone or in combination of two or more as necessary.

  Specific examples of the monomer that is polymerized to become a structural unit (D) having another acid-eliminable group include the following formulas (9-1) to (9-77) and the following formula (9-102). ) To (9-172). In formulas (9-1) to (9-77) and formulas (9-102) to (9-172), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of sensitivity and resolution, the monomer represented by the above formulas (9-1) to (9-3), the monomer represented by the above formula (9-5), the above formula (9- 16), the monomer represented by the above formula (9-19), the monomer represented by the above formula (9-20), and the above formula (9-22). Monomer represented by the above formula (9-23), monomer represented by the above formulas (9-25) to (9-28), and represented by the above formula (9-30). Monomer represented by the above formula (9-31), monomer represented by the above formula (9-33), monomer represented by the above formula (9-34) And monomers represented by the above formulas (9-102) to (9-129), and geometrical isomers and optical isomers thereof are more preferable, and a single monomer represented by the above formula (9-1) Body represented by the above formula (9-2) Body, a monomer represented by the above formula (9-16), a monomer represented by the above formula (9-20), a monomer represented by the above formula (9-23), the above formula ( 9-28), a monomer represented by the above formula (9-31), a monomer represented by the above formula (9-34), and the above formula (9-109) A monomer represented by the above formula (9-111), a monomer represented by the above formulas (9-114) to (9-117), and the above formula (9-125). And the monomer represented by the above formula (9-128) and the above formula (9-129) are particularly preferable.

  Moreover, from the point which is excellent in line edge roughness, it represents with the monomer represented by said Formula (9-35)-(9-40), said Formula (9-52)-(9-62). Monomer, monomer represented by the above formula (9-76), monomer represented by the above formula (9-77), represented by the above formulas (9-130) to (9-135) Monomers represented by the above formulas (9-147) to (9-157), monomers represented by the above formula (9-172), and geometric isomers and optics thereof. Isomers are more preferred.

  Moreover, from the point which is excellent in dry etching tolerance, it represents with the monomer represented by said Formula (9-41)-(9-51), said Formula (9-63)-(9-75). Monomers, monomers represented by the above formulas (9-136) to (9-146), monomers represented by the above formulas (9-158) to (9-171), and these Geometric isomers and optical isomers are more preferred.

  The resist polymer of the present invention may further contain structural units other than those described above. That is, the resist polymer of the present invention comprises a structural unit (A) having an acid leaving group, a structural unit (B) having a lactone skeleton, a structural unit (C) having a hydrophilic group, and other acid leaving groups. It may contain a structural unit other than the structural unit (D) having a functional group.

  For example, a structural unit having an alicyclic skeleton (E) (nonpolar alicyclic skeleton) having no acid leaving group, lactone skeleton and hydrophilic group can be contained. Here, the alicyclic skeleton is a skeleton having one or more cyclic saturated hydrocarbon groups. The structural unit having a nonpolar alicyclic skeleton may be one type or two or more types.

  A resist polymer containing a structural unit having a nonpolar alicyclic skeleton is excellent in dry etching resistance.

  As the structural unit having a nonpolar alicyclic skeleton, structural units represented by the following formulas (11-1) to (11-4) are preferable from the viewpoint of high dry etching resistance required for a resist.

(In the formula, R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ each independently represent a hydrogen atom or a methyl group, and X ³⁰¹ , X ³⁰² , X ³⁰³ and X ³⁰⁴ are each independently a straight chain having 1 to 6 carbon atoms. Or, it represents a branched alkyl group, and n301, n302, n303, and n304 each independently represents an integer of 0 to 4. When n301, n302, n303, and n304 are 2 or more, X ³⁰¹ , X ³⁰² , X ³⁰³ , X ^{304 includes} a plurality of different groups, and p and p1 each independently represents an integer of 0 to 2.)

In the formulas (11-1) to (11-4), the position where X ³⁰¹ , X ³⁰² , X ³⁰³ and X ³⁰⁴ are bonded may be anywhere in the cyclic structure.
N301, n302, n303, and n304 in the formulas (11-1) to (11-4) are preferably 0 from the viewpoint of high dry etching resistance.
P in the formula (11-3) and p1 in the formula (11-4) are preferably 0 from the viewpoint of high solubility in an organic solvent, and 1 from the viewpoint of high dry etching resistance. It is preferable.

  In order to introduce such a structural unit into the polymer, a monomer having a nonpolar alicyclic skeleton may be copolymerized. Monomers having a nonpolar alicyclic skeleton can be used alone or in combination of two or more as required.

  Examples of the monomer having a nonpolar alicyclic skeleton include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, and (meth) acrylate tri Cyclodecanyl, dicyclopentadienyl (meth) acrylate, and derivatives having a linear or branched alkyl group having 1 to 6 carbon atoms on the alicyclic skeleton of these compounds are preferred.

  Specific examples of the monomer having a nonpolar alicyclic skeleton include monomers represented by the following formulas (14-1) to (14-5). In formulas (14-1) to (14-5), R represents a hydrogen atom or a methyl group.

  The resist polymer of the present invention may further contain structural units other than those described above.

  Examples of the monomer that is polymerized into the structural unit include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-propyl (meth) acrylate, (meth ) Isopropyl acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, methoxymethyl (meth) acrylate, n-propoxyethyl (meth) acrylate, (meth) acryl Iso-propoxyethyl acid, n-butoxyethyl (meth) acrylate, iso-butoxyethyl (meth) acrylate, tert-butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic 3-hydroxypropyl acid, 2-hydroxy-n-propyl (meth) acrylate, (Meth) acrylic acid 4-hydroxy-n-butyl, (meth) acrylic acid 2-ethoxyethyl, (meth) acrylic acid 1-ethoxyethyl, (meth) acrylic acid 2,2,2-trifluoroethyl, (meth) Acrylic acid 2,2,3,3-tetrafluoro-n-propyl, (meth) acrylic acid 2,2,3,3,3-pentafluoro-n-propyl, methyl α- (tri) fluoromethylacrylate, α- (tri) fluoromethyl acrylate ethyl, α- (tri) fluoromethyl acrylate 2-ethylhexyl, α- (tri) fluoromethyl acrylate n-propyl, α- (tri) fluoromethyl acrylate iso-propyl, α- (Tri) fluoromethyl acrylate n-butyl, α- (tri) fluoromethyl acrylate iso-butyl, α- (tri) fluoromethyl acrylate Tert-butyl acid, methoxymethyl α- (tri) fluoromethyl acrylate, ethoxyethyl α- (tri) fluoromethyl acrylate, n-propoxyethyl α- (tri) fluoromethyl acrylate, α- (tri) fluoromethyl Iso-propoxyethyl acrylate, n-butoxyethyl α- (tri) fluoromethyl acrylate, iso-butoxyethyl α- (tri) fluoromethyl acrylate, tert-butoxyethyl α- (tri) fluoromethyl acrylate, etc. (Meth) acrylic acid ester having a linear or branched structure;

  Styrene, α-methylstyrene, vinyltoluene, p-hydroxystyrene, p-tert-butoxycarbonylhydroxystyrene, 3,5-di-tert-butyl-4-hydroxystyrene, 3,5-dimethyl-4-hydroxystyrene, aromatic alkenyl compounds such as p-tert-perfluorobutylstyrene and p- (2-hydroxy-iso-propyl) styrene;

  Examples thereof include ethylene, propylene, norbornene, tetrafluoroethylene, acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, vinyl chloride, vinyl fluoride, vinylidene fluoride, and vinylpyrrolidone. These monomers can be used alone or in combination of two or more as required.

  Usually, the sum of the structural units other than the structural unit (A), the structural unit (B), the structural unit (C), and the structural unit (D) is in a range of 20 mol% or less with respect to the entire polymer. preferable.

  Tables 1 and 2 list preferred combinations of structural units of the resist polymer of the present invention.

  In addition, the structural unit (B) includes at least one selected from the group consisting of the above formula (10-1) and the above formula (10-3), the above formulas (10-7), (10-8), One or more selected from the group consisting of (10-10), (10-12), (10-17) and the above formula (10-19) may be used in combination. Furthermore, in addition to the combinations listed in Table 1, as the structural unit (C), the above formula (13-1), the above formula (13-38), the above formula (13-39), the above formula (13-42) ), The above formula (13-43), the above formula (13-60), and a combination of one monomer selected from the group consisting of the above formula (13-96) (hereinafter referred to as “combination A”) Is also preferred. And with respect to the combinations listed in Tables 1 and 2, or the combination A, the structural unit (E) is selected from the group consisting of the above formula (14-1) and the above formula (14-3). A combination in which more than one monomer is added is also preferable.

  The mass average molecular weight of the resist polymer of the present invention is not particularly limited, but is preferably 1,000 or more, more preferably 2,000 or more, from the viewpoint of dry etching resistance and resist pattern shape. Of 5,000 or more, more preferably 5,000 or more. Further, the mass average molecular weight of the resist polymer of the present invention is preferably 100,000 or less, more preferably 50,000 or less, and more preferably 30,000, from the viewpoints of solubility in a resist solution and resolution. The following is particularly preferable, and from the viewpoint of line edge roughness and skirting, 15,000 or less is more preferable.

The method for producing the resist polymer of the present invention will be described.
The resist polymer of the present invention usually comprises one or more monomers having a lactone skeleton, one or more monomers having an acid leaving group, and a hydrophilic group in the presence of a polymerization initiator. It is obtained by copolymerizing a monomer composition containing at least one monomer. The polymerization initiator is preferably one that generates radicals efficiently by heat. Examples of such polymerization initiators include 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 2,2′-azobis [2- (2-imidazoline- Azo compounds such as 2-yl) propane; and organic peroxides such as 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane. In addition, when producing a resist polymer used in ArF excimer laser (wavelength: 193 nm) lithography, the light transmittance of the resulting resist polymer (transmittance for light with a wavelength of 193 nm) is not reduced as much as possible. The polymerization initiator preferably has no aromatic ring in the molecular structure. Furthermore, in consideration of safety during polymerization, the polymerization initiator preferably has a 10-hour half-life temperature of 60 ° C. or higher.

  The method for producing the polymer of the present invention is not particularly limited as long as it is performed by solution polymerization, but a polymerization method called dropping polymerization in which a monomer is dropped into a polymerization vessel is generally preferable. Among them, from the viewpoint that a polymer having a narrow composition distribution and / or molecular weight distribution can be easily obtained, a monomer that becomes a constituent unit of a target polymer by polymerization (even if only a monomer is used, The polymer of the present invention is preferably produced by a polymerization method called dropping polymerization in which the polymerization is carried out while dropping the solution in an organic solvent.

  In the drop polymerization method, for example, an organic solvent is previously charged in a polymerization vessel and heated to a predetermined polymerization temperature, and then a monomer, a polymerization initiator, and a chain transfer agent dissolved in an organic solvent if necessary A body solution (hereinafter also referred to as “dropping solution”) is dropped into an organic solvent in the polymerization vessel. The monomer may be dropped without being dissolved in the organic solvent. In that case, a solution in which the polymerization initiator and, if necessary, the chain transfer agent are dissolved in the monomer is dropped into the organic solvent. Further, the monomer may be dropped into the polymerization vessel without previously charging the organic solvent into the polymerization vessel.

  Moreover, a monomer, a polymerization initiator, and a chain transfer agent can each be dripped individually or in arbitrary combinations.

  Although the polymerization temperature in the dropping polymerization method is not particularly limited, it is usually preferably in the range of 50 to 150 ° C.

  As an organic solvent used in the dropping polymerization method, a known solvent can be used as a polymerization solvent. For example, a chain ether such as ether (diethyl ether, propylene glycol monomethyl ether (hereinafter also referred to as “PGME”), tetrahydrofuran ( (Hereinafter also referred to as “THF”), cyclic ethers such as 1,4-dioxane), esters (methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate (hereinafter also referred to as “PGMEA”). ), Ketone (acetone, methyl ethyl ketone (hereinafter also referred to as “MEK”), methyl isobutyl ketone (hereinafter also referred to as “MIBK”), amide (N, N-dimethylacetamide, N, N-dimethylformamide). ), Sulfoxide Such as dimethyl sulfoxide), hydrocarbons (benzene, toluene, xylene and like aromatic hydrocarbons, aliphatic hydrocarbons such as hexane, and alicyclic hydrocarbons such as cyclohexane), and mixtures of these solvents.

  The monomer concentration of the monomer solution dropped into the organic solvent is not particularly limited, but is preferably in the range of 5 to 50% by mass.

  The amount of the organic solvent charged into the polymerization vessel is not particularly limited and may be determined as appropriate. Usually, it uses within the range of 30-700 mass% with respect to the monomer whole quantity used for copolymerization.

  The polymer solution produced by a method such as solution polymerization can be adjusted to an appropriate solution viscosity with a good solvent such as 1,4-dioxane, acetone, THF, MEK, MIBK, γ-butyrolactone, PGMEA, and PGME. After dilution, the polymer is generally precipitated by reprecipitation or addition by addition in an organic solvent called a poor solvent. This step is very effective for removing unreacted monomers and polymerization initiators remaining in the polymerization solution. If these unreacted substances remain as they are, there is a possibility of adversely affecting the resist performance. Therefore, it is preferable to remove them as much as possible. The reprecipitation process may be unnecessary depending on circumstances. Thereafter, the precipitate is filtered off and sufficiently dried to obtain the polymer of the present invention. Moreover, after filtering off, it can also be used with a wet powder, without drying.

  Examples of the organic solvent used as the precipitation or reprecipitation solvent include hydrocarbons (aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; benzene, toluene, xylene, and the like. Aromatic hydrocarbons), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (chain ethers such as diethyl ether, diisopropyl ether, dimethoxyethane; cyclic ethers such as tetrahydrofuran, dioxane), ketones (Acetone, methyl ethyl ketone, diisobutyl ketone, etc.), ester (ethyl acetate, butyl acetate, etc.), carbonate (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene, etc.) Carbonate, or the like) and the like, is preferably at least one or more selected from these organic solvents.

  Among these, as the organic solvent used as the precipitation or reprecipitation solvent, a solvent containing at least a hydrocarbon (particularly an aliphatic hydrocarbon such as hexane) is preferable. In such a solvent containing at least hydrocarbon, the ratio of the hydrocarbon (for example, aliphatic hydrocarbon such as hexane) and the other solvent is, for example, a volume ratio at 25 ° C. of 10% by volume / 90% by volume to 99%. Volume% / 1 volume%, preferably 30 volume% / 70 volume% to 98 volume% / 2 volume%, more preferably about 50 volume% / 50 volume% to 97 volume% / 3 volume%.

The solubility parameter of the organic solvent used as the precipitation or reprecipitation solvent by the Fedors method (hereinafter sometimes simply referred to as “SP value”) is 7.0 (cal / cm ³ ) ^{1/2 to} 14. It is preferably within the range of 0 (cal / cm ³ ) ^1/2 [14.3 MPa ^{1/2 to} 28.6 MPa ^1/2 ]. When such an organic solvent is used as a poor solvent, a polymer having a composition distribution particularly suitable for a resist can be obtained.

  The SP value of the organic solvent can be determined, for example, by the method described in “Polymer Handbook”, 4th edition, pages VII-675 to VII-711. As the SP value of the organic solvent, the values shown in Table 1 (page VII-683) and Tables 7 to 8 (pages VII-688 to VII-711) of the document can be adopted. The SP value when the organic solvent is a mixed solvent of a plurality of solvents can be determined by a known method. For example, the SP value of the mixed solvent can be obtained as the sum of products of the SP value of each solvent and the volume fraction, assuming that additivity is established.

The SP value of the poor solvent is more preferably 7.0 (cal / cm ³ ) ^{1/2 to} 9.0 (cal / cm ³ ) ^1/2 [14.3 MPa ^{1/2 to} 18.4 MPa ^1/2. And 12.0 (cal / cm ³ ) ^{1/2 to} 14.0 (cal / cm ³ ) ^1/2 [24.5 MPa ^{1/2 to} 28.6 MPa ^1/2 ], particularly preferred Is 7.5 (cal / cm ³ ) ^{1/2 to} 8.5 (cal / cm ³ ) ^1/2 [15.3 MPa ^{1/2 to} 17.4 MPa ^1/2 ], and 13.0 (cal / cm ³ ) ^{1/2 to} 14.0 (cal / cm ³ ) ^1/2 [26.6 MPa ^{1/2 to} 28.6 MPa ^1/2 ].

Next, the resist composition of the present invention will be described.
The resist composition of the present invention is obtained by dissolving the resist polymer of the present invention in a solvent. The chemically amplified resist composition of the present invention is obtained by dissolving the resist polymer of the present invention and a photoacid generator in a solvent. The resist polymer of the present invention may be used alone or in combination of two or more. In addition, without separating the polymer from the polymer solution obtained by solution polymerization or the like, the polymer solution is used as it is for the resist composition, or the polymer solution is diluted with an appropriate solvent, or It can also be concentrated and used in a resist composition.

  Examples of the solvent include linear or branched ketones such as methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone and 2-hexanone; cyclic ketones such as cyclopentanone and cyclohexanone; propylene glycol monomethyl ether acetate, propylene glycol monoethyl Propylene glycol monoalkyl acetates such as ether acetate; Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether Class: ethylene glycol monomethyl ether, ethylene glycol monoe Ethylene glycol monoalkyl ethers such as ether, diethylene glycol dimethyl ether, diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether, ethyl acetate, esters such as ethyl lactate; 1,4-dioxane, ethylene carbonate, .gamma.-butyrolactone. These solvents may be used alone or in combination of two or more.

  The content of the solvent is usually 200 to 5000 parts by mass and more preferably 300 to 2000 parts by mass with respect to 100 parts by mass of the resist polymer (the polymer of the present invention).

  When the resist polymer of the present invention is used for a chemically amplified resist, it is necessary to use a photoacid generator.

  The photoacid generator contained in the chemically amplified resist composition of the present invention can be arbitrarily selected from those that can be used as the acid generator of the chemically amplified resist composition. A photo-acid generator may use 1 type or may use 2 or more types together.

  Examples of such a photoacid generator include onium salt compounds, sulfonimide compounds, sulfone compounds, sulfonic acid ester compounds, quinonediazide compounds, diazomethane compounds, and the like. As the photoacid generator, among them, onium salt compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts are preferable, specifically, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, Triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium hexafluoroantimonate, p-methylphenyldiphenylsulfonium nonafluorobutanesulfonate, Tri (tert-butylphenyl) sulfonium trifluor B methanesulfonate, and the like.

  The content of the photoacid generator is appropriately determined depending on the type of the photoacid generator selected, but is usually 0.1 parts by mass or more with respect to 100 parts by mass of the resist polymer (the polymer of the present invention). Yes, and more preferably 0.5 parts by mass or more. By setting the content of the photoacid generator within this range, a chemical reaction due to the catalytic action of the acid generated by exposure can be sufficiently caused. Moreover, content of a photo-acid generator is 20 mass parts or less normally with respect to 100 mass parts of polymers for resists (polymer of this invention), and it is more preferable that it is 10 mass parts or less. By setting the content of the photoacid generator within this range, the stability of the resist composition is improved, and the occurrence of uneven coating during application of the composition and scum during development is sufficiently reduced.

  Furthermore, a nitrogen-containing compound can also be mix | blended with the chemically amplified resist composition of this invention. By containing a nitrogen-containing compound, the resist pattern shape, the stability over time, and the like are further improved. In other words, the cross-sectional shape of the resist pattern is closer to a rectangle, and the resist film is exposed, post-exposure baked (PEB), and left for several hours before the next development process. However, the deterioration of the cross-sectional shape of the resist pattern is further suppressed when such leaving (aging) is performed.

  As the nitrogen-containing compound, any known compounds can be used, but amines are preferable, and among them, secondary lower aliphatic amines and tertiary lower aliphatic amines are more preferable.

  Here, the “lower aliphatic amine” refers to an alkyl or alkyl alcohol amine having 5 or less carbon atoms.

  Examples of the secondary lower aliphatic amine and tertiary lower aliphatic amine include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tripentylamine, diethanolamine, triethanolamine and the like. Is mentioned. Among these nitrogen-containing compounds, tertiary alkanolamines such as triethanolamine are more preferable.

The nitrogen-containing compound may be used alone or in combination of two or more.
The content of the nitrogen-containing compound is appropriately determined depending on the type of the selected nitrogen-containing compound, but is usually 0.01 parts by mass or more with respect to 100 parts by mass of the resist polymer (the polymer of the present invention). It is preferable. By setting the content of the nitrogen-containing compound within this range, the resist pattern shape can be made more rectangular. Moreover, it is preferable that content of a nitrogen-containing compound is 2 mass parts or less normally with respect to 100 mass parts of polymers for resists (polymer of this invention). By setting the content of the nitrogen-containing compound within this range, it is possible to reduce the sensitivity deterioration.

  In addition, the chemically amplified resist composition of the present invention may contain an organic carboxylic acid, a phosphorus oxo acid, or a derivative thereof. By containing these compounds, it is possible to prevent sensitivity deterioration due to the compounding of the nitrogen-containing compound, and further improve the resist pattern shape, the stability with time of standing, and the like.

  As the organic carboxylic acid, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are preferable.

  Phosphorus oxoacids or derivatives thereof include, for example, phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid and derivatives thereof; phosphonic acid, phosphonic acid dimethyl ester Phosphonic acids such as phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester, etc. and derivatives thereof; phosphinic acids such as phosphinic acid, phenylphosphinic acid and their Examples thereof include derivatives such as esters, and among them, phosphonic acid is preferable.

  These compounds (organic carboxylic acid, phosphorus oxo acid, or derivatives thereof) may be used alone or in combination of two or more.

  The content of these compounds (organic carboxylic acid, phosphorus oxo acid, or derivative thereof) is appropriately determined depending on the type of the selected compound and the like, but is usually a resist polymer (the polymer of the present invention) 100. It is preferable that it is 0.01 mass part or more with respect to a mass part. By setting the content of these compounds within this range, the resist pattern shape can be made more rectangular. In addition, the content of these compounds (organic carboxylic acid, phosphorus oxo acid or derivative thereof) is usually 5 parts by mass or less with respect to 100 parts by mass of the resist polymer (the polymer of the present invention). It is preferable. By reducing the content of these compounds within this range, the film loss of the resist pattern can be reduced.

  Note that both the nitrogen-containing compound and the organic carboxylic acid, phosphorus oxoacid, or a derivative thereof can be contained in the chemically amplified resist composition of the present invention, or only one of them can be contained. .

  Furthermore, the resist composition of the present invention may contain various additives such as surfactants, other quenchers, sensitizers, antihalation agents, storage stabilizers, and antifoaming agents as necessary. it can. Any of these additives can be used as long as it is known in the art. Moreover, the compounding quantity of these additives is not specifically limited, What is necessary is just to determine suitably.

  The resist polymer of the present invention may be used as a resist composition for metal etching, photofabrication, plate making, hologram, color filter, retardation film and the like.

Next, an example of the pattern manufacturing method of the present invention will be described.
First, the resist composition of the present invention is applied to the surface of a substrate to be processed such as a silicon wafer for producing a pattern by spin coating or the like. And the to-be-processed board | substrate with which this resist composition was apply | coated is dried by baking processing (prebaking) etc., and a resist film is manufactured on a board | substrate.

Next, the resist film thus obtained is irradiated with light having a wavelength of 250 nm or less through a photomask (exposure). The light used for exposure is preferably a KrF excimer laser, an ArF excimer laser, or an F ₂ excimer laser, and particularly preferably an ArF excimer laser. It is also preferable to expose with an electron beam.

  After the exposure, heat treatment is appropriately performed (post-exposure baking, PEB), the substrate is immersed in an alkaline developer, and the exposed portion is dissolved and removed in the developer (development). Any known alkaline developer may be used. Then, after development, the substrate is appropriately rinsed with pure water or the like. In this way, a resist pattern is manufactured on the substrate to be processed.

  Usually, a substrate to be processed on which a resist pattern has been manufactured is appropriately heat-treated (post-baked) to strengthen the resist and selectively etch portions without the resist. After etching, the resist is usually removed using a release agent.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, “part” in each example and comparative example means “part by mass” unless otherwise specified.

  Moreover, the physical property etc. of the polymer manufactured as follows were measured.

<Mass average molecular weight of resist polymer>
About 20 mg of the resist polymer is dissolved in 5 mL of THF, and filtered through a 0.5 μm membrane filter to prepare a sample solution. This sample solution is measured using Tosoh gel permeation chromatography (GPC). did. In this measurement, a separation column was manufactured by Showa Denko, and three Shodex GPC K-805L (trade name) in series, the solvent was THF, the flow rate was 1.0 mL / min, the detector was a differential refractometer, and the measurement temperature. Measurements were made using polystyrene as the standard polymer at 40 ° C. and an injection volume of 0.1 mL.

<Average copolymer composition ratio of resist polymer (mol%)>
^It calculated | required by the measurement of < ¹ > H-NMR. This measurement is performed using JSX Corporation GSX-400 type FT-NMR (trade name), deuterated chloroform, deuterated acetone or deuterated about 5 mass% resist polymer sample. The dimethyl sulfoxide solution was put in a test tube having a diameter of 5 mmφ, and the measurement was carried out 64 times in a single pulse mode at a measurement temperature of 40 ° C., an observation frequency of 400 MHz.

  Moreover, using the produced polymer, a resist composition was prepared as follows, and its physical properties and the like were measured.

<Preparation of resist composition>
100 parts of the prepared resist polymer, 2 parts of triphenylsulfonium triflate as a photoacid generator, and 700 parts of PGMEA as a solvent were mixed to obtain a uniform solution, and then filtered through a membrane filter having a pore size of 0.1 μm. Then, a resist composition solution was prepared.

<Manufacture of resist pattern>
The prepared resist composition solution was spin-coated on a silicon wafer and pre-baked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 0.4 μm. Next, after exposure using an ArF excimer laser exposure machine (wavelength: 193 nm), post-exposure baking was performed using a hot plate at 120 ° C. for 60 seconds. Subsequently, it developed at room temperature using the 2.38 mass% tetramethylammonium hydroxide aqueous solution, wash | cleaned with the pure water, and dried, and the resist pattern was manufactured.

<Sensitivity>
The exposure amount (mJ / cm ² ) at which a 0.16 μm line-and-space pattern mask was transferred to a line width of 0.16 μm was measured as sensitivity.

<Resolution>
The minimum dimension (μm) of the resist pattern resolved when exposed with the above exposure amount was defined as the resolution.

<Storage stability of resist composition>
For the prepared resist composition solution, the resist sensitivity after being allowed to stand at 4 ° C. for 1 week was measured in the same manner as described above, and the resist calculated by (resist sensitivity after aging) − (resist sensitivity immediately after preparation) The amount of change in sensitivity during storage of the composition was evaluated.

  In addition, it means that it is excellent in the storage stability of a resist composition, so that the absolute value of the said sensitivity change amount is small.

<Synthesis Example 1>
Under a nitrogen atmosphere, 35.6 parts of PGMEA was placed in a flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer, and the temperature of the hot water bath was raised to 80 ° C. while stirring. 8- or 9-acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one represented by the following formula (51) (hereinafter referred to as OTDA) 17.8 Part, cyclohexyloxyethoxy methacrylate (hereinafter referred to as ACHMA) represented by the following formula (52) 17.0 parts, 2- or 3-cyano-5-norbornyl methacrylate represented by the following formula (53) (Hereinafter referred to as CNNMA) Contains a monomer solution in which 8.2 parts, 64.4 parts of PGMEA, and 2.30 parts of 2,2′-azobisisobutyronitrile (hereinafter referred to as AIBN) are mixed. From the dropping device, it was dropped into the flask at a constant rate over 6 hours. Then, the temperature of 80 degreeC was hold | maintained for 1 hour and the polymerization reaction was performed.

<Example 1>
The reaction solution obtained in Synthesis Example 1 was dropped into 1500 mL of a mixed solution of hexane / ethyl acetate = 9/1 (volume ratio; 25 ° C.) with stirring to obtain a white precipitate. The SP value of the hexane / ethyl acetate = 9/1 (volume ratio; 25 ° C.) mixture was 7.5 (cal / cm ³ ) ^1/2 (= 15.3 MPa ^1/2 ). . Then, the precipitate was filtered off, dried at 25 ° C. under reduced pressure for about 3 hours, dissolved again in 100 parts of PGMEA, and the above-described precipitation purification operation was repeated to obtain a purified white precipitate (polymer A-1). ) Was obtained. The resulting precipitate was filtered off and dried under reduced pressure at 60 ° C. for about 40 hours. Table 3 shows a result obtained by measuring properties of the obtained polymer A-1.

<Comparative Example 1>
A polymer B-1 was obtained in the same manner as in Example 1 except that methanol / water = 9/1 instead of the hexane / ethyl acetate = 9/1 mixed solution. The SP value of the methanol / water = 9/1 (volume ratio; 25 ° C.) mixture was 15.4 (cal / cm ³ ) ^1/2 (= 31.5 MPa ^1/2 ). Table 3 shows a result obtained by measuring properties of the obtained polymer B-1.

<Synthesis Example 2>
Under a nitrogen atmosphere, 34.1 parts of PGMEA was placed in a flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer, and the temperature of the hot water bath was raised to 80 ° C. while stirring. Α-methacryloyloxy-γ-butyrolactone (hereinafter referred to as GBLMA) 13.6 parts represented by the following formula (54), 2-methacryloyloxy-2-methyladamantane (hereinafter referred to as the following formula (55)) 9.4 parts, ACHMA 8.5 parts of the formula (52), 1-methacryloyloxy-3-hydroxyadamantane (hereinafter referred to as HAdMA) represented by the following formula (56). From a dropping apparatus containing a monomer solution in which 4 parts, 61.3 parts of PGMEA and 2.76 parts of dimethyl-2,2′-azobisisobutyrate (hereinafter referred to as DAIB) were mixed, 6 It was dropped into the flask over time. Then, the temperature of 80 degreeC was hold | maintained for 1 hour and the polymerization reaction was performed.

<Example 2>
In the same manner as in Example 1, Polymer A-2 was obtained. Table 3 shows a result obtained by measuring properties of the obtained polymer A-2.

<Comparative example 2>
Instead of methanol / water = 9/1 mixed solution, methanol / water = 8/2 (volume ratio; 25 ° C., SP value of the mixed solution = 16.3 (cal / cm ³ ) ^1/2 (= 33.3 MPa) ^A polymer B-2 was obtained in the same manner as in Comparative Example 1 except that ^1/2 )) was used. Table 3 shows a result obtained by measuring properties of the obtained polymer B-2.

  The resist compositions (Examples 1 and 2) using the resist polymer obtained by the production method of the present invention had sufficient sensitivity and resolution, and were excellent in storage stability.

  On the other hand, the resist composition (Comparative Examples 1 and 2) using the resist polymer obtained by the production method in which the SP value of the precipitation and reprecipitation solvent is out of the range of the present invention is ACHMA during the precipitation or reprecipitation operation. The storage stability of the resist composition was inferior due to the influence of methacrylic acid, which was thought to be produced by hydrolysis.

Claims (7)

Following formula (1)

(In the formula (1), R ¹¹ represents a hydrogen atom or a methyl group. Z represents a single bond, a divalent to tetravalent group derived from an alkane, or a divalent to tetravalent alicyclic carbon atom having 4 to 20 carbon atoms. Represents a hydrogen group, —C (═O) —, —S (═O) ₂ —, or a combination thereof, or a bivalent to tetravalent group, n represents an integer of 1 to 3, A represents a methyl group, R ¹⁴ represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 5 carbon atoms.
And at least one hydrogen atom of the methyl group of the group A is a method for producing a resist polymer containing a structural unit (A1) having a partial charge of 0.150 or more, which is obtained by a solution polymerization method. The resulting polymer solution is precipitated or re-precipitated by adding it to at least one organic solvent selected from hydrocarbons, halogenated hydrocarbons, nitro compounds, nitriles, ethers, ketones, esters and carbonates. A method for producing a resist polymer. The solubility parameter according to the Fedors method of the organic solvent used as the precipitation or reprecipitation solvent is 7.0 (cal / cm ³ ) ^{1/2 to} 14.0 (cal / cm ³ ) ^1/2 [14.3 MPa. ^The method for producing a resist polymer according to claim 1, wherein the resist polymer has a range of ^{1/2 to} 28.6 MPa ^1/2 ]. The resist polymer according to claim 1 or 2, further comprising a structural unit (B) having a lactone skeleton that is at least one selected from the group consisting of the following formulas (4-1) to (4-5). Production method.

(In the above formula, R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁵¹ , R ⁶¹ and R ⁷¹ each independently represents a hydrogen atom or a methyl group, and R ⁴⁰¹ , R ⁴⁰² , R ²⁰¹ , R ²⁰² , R ^{203, R 204, R 91,} R 92, R 93, R 94, a 1, a 2, a 3, a 4 are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy groups Represents a carboxy group or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, and X ⁴¹ , X ⁴² , X ⁴³ and X ⁴⁴ are each a hydroxy group, a carboxy group, or an acyl having 1 to 6 carbon atoms as a substituent. A carbon number which may have at least one group selected from the group consisting of a group, an alkoxy group having 1 to 6 carbon atoms, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, a cyano group and an amino group 1-6 linear or branched alkyl groups, hydroxy , A carboxy group, an acyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or an amino group, n41, n42, n43, n44 .n41 is an integer of 0~4, n42, n43, when n44 is 2 or ^{more, X 41, X 642, X} 43, X 44 comprises also each have a plurality of different groups .Y ^11, Y ²¹ and Y ³¹ each independently represent —CH ₂ — or —CO—O—, of which at least one represents —CO—O—, i represents 0 or 1, and m and m1 represent 1 or 2 R ⁴⁰¹ and R ⁴⁰² (when i = 1), R ⁹¹ and R ⁹² (when m1 = 1) are taken together to form a methylene chain having 2 to 6 carbon atoms [— (CH ₂ ) _j − (J represents an integer of 2 to 6)] or a methylene chain having 1 to 6 carbon atoms including —O—, —S—, and —NH— [— (C _{2) k} - (k may form a representative) an integer of 1-6, in the case of R ⁹¹ s or R ⁹² together (m1 = 2), and A ¹ and A ^2, A ³ and A ⁴ Together may contain —O—, —S—, —NH—, methylene chain having 1 to 6 carbon atoms [— (CH ₂ ) ₁ — (l represents an integer of 1 to 6)] Or -O-, -S-, or -NH- may be formed.) Furthermore, the resist in any one of Claims 1-3 containing the structural unit (C) which has a hydrophilic group which is at least 1 sort (s) chosen from the group which consists of following formula (5-1)-(5-7). Production method for polymer.

(In the above formula, R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ each independently represents a hydrogen atom or a methyl group, and R ⁵⁰¹ , R ⁵⁰² , R ⁵⁰³ , R ⁵⁰⁶ are each Independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁵⁰⁴ and R ⁵⁰⁵ each independently represents an alkyl group having 1 to 3 carbon atoms, and R ⁵³¹ , R ⁵³² , R ⁵³³ , R ⁵³⁴ , R ⁵³⁵ , R ⁵³⁶ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, R ⁵⁷¹ and R ⁵⁷² are bridged cyclic hydrocarbon groups having 4 to 16 carbon atoms, or 4 to 4 carbon atoms A straight chain or branched alkyl group having 1 to 6 carbon atoms having 16 bridged cyclic hydrocarbon groups, and a bridged cyclic carbonization having 4 to 16 carbon atoms together with the carbon atom to which R ⁵⁷¹ and R ⁵⁷² are bonded A hydrogen group may be formed, and W ¹ , W ² , and W ³ are each independently —O—, —S—, -NH- or a methylene chain having a chain length of 1 to 6 [-(CH ₂ ) _t- (t represents an integer of 1 to 6)], X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , X ⁵⁶ and X ⁵⁷ each independently represent —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms as a substituent. of carboxy group and a linear or branched alkyl group having at least one carbon atoms which may have a group 1 to 6 chosen from the group consisting of amino _{groups, -C (CF 3) 2 -OH} , hydroxy group , A cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxy group or an amino group esterified with an alcohol having 1 to 6 carbon atoms, n51, n52, n53 , N54, n55, and n56 represent an integer of 1 to 4. q1, q2 represents 0 or 1. Incidentally, n51, n52, n53, n54 , n55, when n56 is 2 or ^{more, X 51, X 52, X} 53, X 54, X 55, X 56 are each It includes having a plurality of different groups.
Here, the alkyl group of R ⁵⁷¹ and R ⁵⁷² and the bridged cyclic hydrocarbon group may have a linear or branched alkyl group having 1 to 6 carbon atoms, and may be a hydroxy group, a carboxy group, or a carbon number of 2 It may have a carboxy group esterified with an acyl group of -6 or an alcohol having 1 to 6 carbon atoms. )   The resist polymer manufactured by the method of any one of Claims 1-4.   A resist composition comprising the resist polymer according to claim 5.   A pattern manufacturing method comprising a step of applying the resist composition according to claim 6 on a substrate to be processed, a step of exposing with light having a wavelength of 250 nm or less, and a step of developing using a developer.