JP5059419B2 - Polymer, resist composition, and method for producing substrate on which pattern is formed - Google Patents

Description

  The present invention relates to a resist polymer, a resist composition containing the same, and a method for producing a substrate on which a pattern is formed, and more particularly to a resist composition suitable for microfabrication using excimer laser and electron beam lithography.

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 technique for miniaturization, generally, the wavelength of irradiation light is shortened. Specifically, the irradiation light has been changed from conventional ultraviolet rays typified by g-line (wavelength: 438 nm) and i-line (wavelength: 365 nm) to shorter wavelength DUV (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 EUV excimer laser (wavelength: 13 nm) lithography technology aiming at shorter wavelengths have been studied. ing. Furthermore, recently, these immersion lithography techniques have also been studied. Also, as a different type of lithography technology, electron beam lithography technology has been energetically studied.

As such a high-resolution resist using short-wavelength irradiation light or electron beam, a chemically amplified resist containing a photoacid generator has been proposed, and improvement and development of this chemically amplified resist are currently underway. Yes.
For example, as a chemically amplified 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. As such acrylic resins, for example, Patent Document 1 and Patent Document 2 describe the weight of (meth) acrylic acid ester having an adamantane skeleton in the ester portion and (meth) acrylic acid ester having a lactone skeleton in the ester portion. Coalescence is disclosed.

However, when these acrylic resins are used as a resist composition, the depth of focus may not be sufficient, and the yield may be reduced in the resist pattern manufacturing process.
Further, a development defect called a defect may occur during the development process using an alkali developer for producing a resist pattern. In addition, a defect may occur in the resist pattern obtained by this defect. As a result, circuit disconnection, defects, and the like may occur, and the yield in the semiconductor manufacturing process may be reduced.
Furthermore, there is a concern that the resist may be insufficient in dry etching resistance due to the thin film thickness of the resist.

Patent Document 3, Patent Document 4 and Patent Document 5 disclose resist compositions using a polymer having a heteroaromatic ring.
However, although these resins are excellent in resist dry etching resistance, especially in the case of ArF excimer laser (wavelength: 193 nm) lithography, the light transmittance of the polymer at the exposure wavelength is often insufficient, and the sensitivity of the resist composition And may adversely affect resolution.
JP 10-319595 A JP-A-10-274852 JP 2005-114968 A JP 2004-163877 A JP 2006-276458 A

When used in resist compositions such as DUV excimer laser lithography, the present invention provides a high sensitivity, high resolution, wide focal depth margin, high light transmittance, few defects during development, and a thin resist film. It is an object of the present invention to provide a polymer having dry etching resistance that can withstand crystallization.
Furthermore, it aims at providing the manufacturing method of the resist composition containing the said polymer, and the board | substrate with which the pattern was formed using this resist composition.

1st invention for solving the said subject has the structural unit (A-2) which has the naphthalene skeleton represented by the following Formula (1-2), and the structural unit represented by the following Formula (5-1). A resist polymer to be contained (hereinafter referred to as “polymer (P)”).
Moreover, 2nd invention is the resist composition containing a polymer (P).
Furthermore, in the third invention, a pattern having a step of coating the resist composition on a substrate to form a resist film, a step of exposing with light having a wavelength of 250 nm or less, and a step of developing with a developer is formed. A method for manufacturing a substrate.

In formula (1-2), R ^Ten Represents a hydrogen atom or a methyl group. Y is -CH ₂ -C (= O) -OH, -OH, -CH ₂ -C (= O) -OR ¹³ Or -OR ¹³ Represents. R ¹³ Represents a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may have a hetero atom.
L ¹ Is-(C (R ²⁰¹ ) (R ²⁰² ) -C (R ²⁰³ ) (R ²⁰⁴ ) -O) _k1 -Or- (C (R ²¹¹ ) (R ²¹² ) -C (R ²¹³ ) (R ²¹⁴ ) -C (R ²¹⁵ ) (R ²¹⁶ ) -O) _k2 -Represents. R ²⁰¹ ~ R ²⁰⁴ And R ²¹¹ ~ R ²¹⁶ Each independently represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 3 carbon atoms.
This hydrocarbon group may have a hetero atom. k1 and k2 each independently represent an integer of 1 to 3.
R ⁵¹ Represents a hydrogen atom or a methyl group.
R ⁵⁰¹ Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
X ⁵¹ Represents a C1-C6 linear or branched alkyl group having a cyano group or at least one cyano group. X ⁵¹ The position substituted with may be any position in the ring structure.
n51 represents an integer of 1 to 4. When n51 is 2 or more, X ⁵¹ Can have a plurality of different groups.

  The polymer (P) of the present invention has a high light transmittance with respect to excimer laser light, and is excellent in the copolymerizability of the monomer as a raw material of the polymer (P). Further, the resist composition of the present invention has high sensitivity and high resolution, a wide focal depth margin, and few defects during development. Furthermore, the resist obtained by the present invention has high dry etching resistance that can withstand the thinning of the resist film.

Furthermore, when the polymer (P) of the present invention is used as a resist composition for immersion, a resist pattern can be formed with high resolution. Therefore, the polymer (P) and the resist composition of the present invention are suitable for lithography using a DUV excimer laser, immersion lithography and electron beam lithography thereof, particularly lithography using an ArF excimer laser and immersion lithography.
Moreover, the board | substrate with which the highly accurate fine pattern was formed can be manufactured with the manufacturing method of the board | substrate of this invention.

Structural unit (A)

In the present invention, the structural unit (A) having a naphthalene skeleton represented by the formula (1-1) is included as a structural unit of the polymer (P).
When the structural unit (A) is contained in the polymer (P), when used as a resist composition for immersion exposure, particularly when the immersion liquid is pure water, the structural unit (A) is a resist composition. It has the effect of reducing the defects of objects.

  The content of the structural unit (A) is preferably 2 mol% or more in the polymer (P) and more preferably 4 mol% or more in terms of the dry etching resistance and refractive index of the resist. The content of the structural unit (A) is preferably 20 mol% or less, more preferably 15 mol% or less, and still more preferably 10 mol% or less, from the viewpoint of the sensitivity and resolution of the resist composition.

R ¹⁰ in formula (1-1) represents a hydrogen atom or a methyl group.
L ¹ in the formula (1-1) is — (C (R ²⁰¹ ) (R ²⁰² ) —C (R ²⁰³ ) (R ²⁰⁴ ) —O) _k1 — or — (C (R ²¹¹ ) (R ²¹² ) — C ( ^R213 ) ( ^R214 ) -C ( ^R215 ) ( ^R216 ) -O) _k2- . R ²⁰¹ to R ²⁰⁴ and R ²¹¹ to R ²¹⁶ are each independently a hydrogen atom, a straight-chain or branched hydrocarbon group having 1 to 3 carbon atoms. This hydrocarbon group may have a hetero atom.
Examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom.
K1 and k2 in Formula (1-1) each independently represent an integer of 1 to 3. Among these, k1 and k2 are preferably 1 from the viewpoint of dry etching resistance of the resist, and k1 and k2 are preferably 2 or 3 from the viewpoint of solubility of the polymer (P) in an organic solvent.
Examples of L ¹ include the following formulas (2-1) to (2-19).

L ¹ in formula (1-1) is preferably formula (2-1) to formula (2-6) and formula (2-17) in terms of the glass transition temperature of the polymer (P).

Y in formula (1-1) represents —CH ₂ —C (═O) —OH, —OH, —CH ₂ —C (═O) —OR ¹³ or —OR ¹³ . R ¹³ represents a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may have a hetero atom.

Y is preferably —OH and —OR ¹³ , more preferably —OH, in terms of light transmittance at a wavelength of 193 nm to the polymer (P).
R ¹³ represents a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may have a hetero atom.
Examples of R ¹³ include the following formulas (3-1) to (3-27).

Y in the formula (1-1) is preferably —CH ₂ —C (═O) —OH or —OH in terms of the defect of the resist composition, the resist sensitivity, and the line edge roughness of the resist. From the viewpoint of storage stability of the product, —CH ₂ —C (═O) —OR ¹³ or —OR ¹³ is preferable, and R ¹³ is represented by the following formulas (1-21) to (1-24). Acid leaving groups are preferred.
In the present invention, the “acid leaving group” refers to a group that decomposes or leaves by the action of an acid.

In formula (1-21) and formula (1-23), R ¹²¹ , R ¹²² , R ¹²³ , R ¹⁴¹ , R ¹⁴² and R ¹⁴³ represent any of the following.
(I) R ¹²¹ , R ¹²² , R ¹²³ , R ¹⁴¹ , R ¹⁴² and R ¹⁴³ 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. Represents a chain or branched alkyl group. Further, at least one of R ¹²¹ , R ¹²² and R ¹²³ and at least one of R ¹⁴¹ , R ¹⁴² and R ¹⁴³ represents this alicyclic hydrocarbon group or a derivative thereof.
(Ii) any two of R ¹²¹ , R ¹²² and R ¹²³ and any two of R ¹⁴¹ , R ¹⁴² and R ¹⁴³ are bonded to each other, and together with the carbon atoms to which they are bonded, the number of carbon atoms is 4 To 20 divalent alicyclic hydrocarbon groups or derivatives thereof. The remaining one of R ¹²¹ , R ¹²² and R ¹²³ which did not participate in the bond and the other one of R ¹⁴¹ , R ¹⁴² and R ¹⁴³ which did not participate in the bond are straight chain having 1 to 4 carbon atoms Alternatively, it represents a branched alkyl group, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

In formula (1-22) and formula (1-24), R ¹³¹ , R ¹³² , R ¹³³ , R ¹⁵¹ , R ¹⁵² and R ¹⁵³ represent any of the following.
(I) R ¹³³ and R ¹⁵³ represents a monovalent alicyclic hydrocarbon group or a derivative thereof or a linear or branched alkyl group having 1 to 4 carbon atoms having 4 to 20 carbon atoms. R ¹³¹ , R ¹³² , R ¹⁵¹ and R ¹⁵² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.
(Ii) two of R ¹³¹ and R ¹³³ , R ¹³² and R ¹³³ , R ¹⁵¹ and R ¹⁵³ or R ¹⁵² and R ¹⁵³ are bonded to each other, and together with the carbon atom to which each is bonded, A divalent alicyclic hydrocarbon group or a derivative thereof is formed. The remaining one of R ¹³¹ and R ¹³² that did not participate in bonding and the remaining one of R ¹⁵¹ and R ¹⁵² that did not participate in bonding represent a hydrogen atom.

X ¹ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms having a hydroxy group or a hydroxy group or a cyano group as a substituent, in terms of defects in the resist composition and resist pattern rectangularity.
h11 is preferably 0 in terms of the resolution of the resist composition.

The structural unit (A) can be used alone or in combination of two or more.
The structural unit (A) is preferably represented by the following formula (1-2) from the viewpoint of transparency to the excimer laser beam having a wavelength of 193 nm of the polymer (P).

In formula (1-2), R ¹⁰ , L ¹ and Y have the same meanings as formula (1-1), respectively.
The structural unit (A) represented by the formula (1-2) can be used alone or in combination of two or more.
The polymer (P) containing the structural unit (A) represented by the formula (1-2) is obtained by polymerizing a monomer containing the monomer (a) represented by the following formula (1-3). Can be manufactured.

In formula (1-3), R ¹⁰ , L ¹ and Y have the same meaning as in formula (1-1).

  Examples of the monomer (a) represented by the formula (1-3) include monomers represented by the following formulas (8-1) to (8-16). In formula (8-1) to formula (8-16), R represents a hydrogen atom or a methyl group.

  Among these, the monomers represented by the formulas (8-1) to (8-8) and geometric isomers and optical isomers thereof are preferable from the viewpoint of the line edge roughness of the resist. From the viewpoint of the sensitivity, the monomers represented by the formulas (8-9) to (8-16), and geometric isomers and optical isomers thereof are preferable.

The monomer (a) can be produced by a known method. Hereinafter, the production method of the monomer (a) will be described by taking the formula (8-9) as an example.
The monomer represented by the formula (8-9) is, for example, 2-bromo-6-t-butoxycarbonyloxynaphthalene represented by the following formula (9-2) or 2-chloro-6- 6 represented by the following formula (9-3). It is obtained by reacting t-butoxycarbonyloxynaphthalene with sodium (meth) acrylate ethyl oxide of the following formula (11-1) or potassium (meth) acrylate ethyl oxide of the following formula (11-2).

R ¹⁰ represents a hydrogen atom or a methyl group.

  The amount of sodium (meth) acrylic acid ethyl oxide or potassium (meth) acrylic acid ethyl oxide used is 2-bromo-6-t-butoxycarbonyloxynaphthalene of formula (9-2) or 2- (2) of formula (9-3). 70-500 mol part is preferable with respect to 100 mol part of chloro-6-t-butoxycarbonyloxynaphthalene. When the amount used is 70 mol parts or more, the monomer of the formula (8-9) tends to be obtained with good yield. Moreover, when this usage-amount is 500 mol part or less, it exists in the tendency which can suppress a by-product production | generation. As for this usage-amount, 100-200 mol part is more preferable.

  In the reaction, the reaction temperature is preferably -20 ° C to 100 ° C. When the reaction temperature is −20 ° C. or higher, the monomer of formula (8-9) tends to be obtained with good yield. Moreover, when reaction temperature is 100 degrees C or less, it exists in the tendency which can suppress the production | generation of the dimethacrylate body which is a by-product. The reaction temperature is more preferably 0 to 50 ° C.

  In the reaction, a solvent can be used. Examples of the solvent include toluene, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, acetonitrile, dichloromethane, chloroform and benzene. Among these, in terms of the solubility of 2-bromo-6-t-butoxycarbonyloxynaphthalene of formula (9-2) or 2-chloro-6-t-butoxycarbonyloxynaphthalene of formula (9-3). Toluene, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide and acetonitrile are preferred.

In the present invention, in the polymer (P) containing the structural unit (A), when the structural unit (A) has an acid-eliminable group (formula (1-1) or formula (1-2) When Y in () is an acid-eliminable group), the acid-eliminable group is eliminated, so that it becomes soluble in alkali, and a resist pattern can be formed. In the case where the structural unit (A) does not have an acid leaving group (Y in Formula (1-1) or Formula (1-2) is —CH ₂ —C (═O) —OH or — In the case of OH), since the structural unit (A) itself is acidic, the polymer (P) containing the structural unit (A) becomes soluble in alkali, and a resist pattern can be formed.

When the structural unit (A) has an acid leaving group, the structural unit (A) also corresponds to the structural unit (C) having an acid leaving group described later. In the present invention, such a structural unit is regarded as the structural unit (A).
Further, when the structural unit (A) has a hydrophilic group, the pattern rectangularity of the resist tends to be good. In this case, the structural unit (A) also corresponds to a structural unit (D) described later, but in the present invention, such a structural unit is regarded as the structural unit (A).

The polymer (P) of the present invention contains a structural unit (A), but if necessary, a structural unit (B) having a lactone skeleton, a structural unit having an acid-eliminating group not having a naphthalene skeleton ( Other structural units such as C) and a structural unit (D) having a hydrophilic group may be contained.

Structural unit (B)

The structural unit (B) having a lactone skeleton is preferably used as a structural component of the polymer (P) because it exhibits the effect of developing the adhesion of the resist composition to the substrate.
The content of the structural unit (B) is preferably 30 mol% or more, more preferably 35 mol% or more in the polymer (P) from the viewpoint of the adhesion of the resist composition to the substrate. The content of the structural unit (B) is preferably 60 mol% or less, more preferably 55 mol% or less, and more preferably 50 mol% or less in the polymer (P) from the viewpoint of the sensitivity and resolution of the resist composition. Further preferred.

Moreover, when the structural unit (B) has an acid leaving group, the sensitivity of the resist composition tends to be more excellent. In this case, the structural unit (B) corresponds to a structural unit (C) described later. In the present invention, such a structural unit is regarded as the structural unit (B).
Further, when the structural unit (B) has a hydrophilic group, the resist pattern rectangularity tends to be good. In this case, the structural unit (B) also corresponds to a structural unit (D) described later. In the present invention, such a structural unit is regarded as the structural unit (B).

  The structural unit (B) is preferably at least one selected from the group consisting of the following formulas (4-1) to (4-6) in terms of the sensitivity of the resist composition or the resistance to dry etching of the resist.

In formula (4-1) to formula (4-6), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ²⁰⁵ , R ²⁰⁶ and R ²⁰⁷ each independently represent a hydrogen atom or a methyl group.

R ²¹⁰ and R ²¹¹ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

^{R 201, R 202, R 203} , R 204, R 93, R 94, R 208 and R ²⁰⁹ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy group, carboxy group or C The carboxy group esterified with the alcohol of number 1-6 is represented.

R ⁴⁰¹ , R ⁴⁰² , A ¹ , A ² , A ³ , A ⁴ , R ⁹¹ , R ⁹² , A ⁵ and A ⁶ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy A carboxy group esterified with a group, a carboxy group or an alcohol having 1 to 6 carbon atoms, or R ⁴⁰¹ and R ⁴⁰² , A ¹ and A ² , A ³ and A ⁴ , R ⁹¹ and R ⁹² and A ⁵ And A ⁶ together form —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _j — (j represents an integer of 1 to 6)). To express.

X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ are each independently a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, an acyl group having 1 to 6 carbon atoms, or 1 to 1 carbon atoms. 6 represents an alkoxy group, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, a cyano group, or an amino group. The linear or branched alkyl group having 1 to 6 carbon atoms is a hydroxy group, a carboxy group, an acyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms as a substituent. It may have at least one group selected from the group consisting of an esterified carboxy group, cyano group and amino group.
n5, n6, n7, n8 and n9 each independently represents an integer of 0 to 4. When n5, n6, n7, n8 and n9 are 2 or more, X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ can each have a plurality of different groups.

Y ¹¹ , Y ¹² and Y ¹³ each independently represent —CH ₂ — or —C (═O) —O—, and at least one of them represents —C (═O) —O—.
Y ²¹ and Y ²² each independently represent —CH ₂ — or —C (═O) —, and at least one of them represents —C (═O) —.
i represents 0 or 1; m and m1 represent 1 or 2.

N5 in the formula (4-1) is preferably 0 in terms of resistance to dry etching of the resist.
M in the formula (4-1) is preferably 1 in terms of sensitivity and resolution of the resist composition.

In formula (4-2), A ¹ and A ² are preferably combined together to form —CH ₂ — or —CH ₂ CH ₂ — in view of dry etching resistance of the resist. From the viewpoint of the solubility in the organic solvent, it is preferable that they become -O- together.
In formula (4-2), R ²⁰¹ and R ²⁰² are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
N6 in the formula (4-2) is preferably 0 in terms of resistance to dry etching of the resist.

In formula (4-3), A ³ and A ⁴ are preferably combined together to form —CH ₂ — or —CH ₂ CH ₂ — in view of dry etching resistance of the resist. From the viewpoint of the solubility in the organic solvent, it is preferable that they become -O- together.
In formula (4-3), R ²⁰³ and R ²⁰⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
N7 in the formula (4-3) is preferably 0 in terms of dry etching resistance of the resist.

In formula (4-4), R ²⁰⁵ , R ²⁰⁶ and R ²⁰⁷ are preferably hydrogen atoms from the viewpoint of solubility of the polymer (P) in an organic solvent.
Y ¹¹ , Y ¹² and Y ¹³ in the formula (4-4) are —C (═O) —O—, one of which is —C (═O) —O— from the viewpoint of the adhesion of the resist composition to the substrate surface, etc. It is preferable that one is —CH ₂ —.
N8 in the formula (4-4) is preferably 0 in terms of dry etching resistance of the resist.

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 solubility of the polymer (P) in an organic solvent.
In formula (4-5), m1 is preferably 1 in terms of the sensitivity and resolution of the resist composition.

In formula (4-6), A ⁵ and A ⁶ are preferably combined together to form —CH ₂ — or —CH ₂ CH ₂ — in view of dry etching resistance of the resist. Polymer (P) From the viewpoint of the solubility in the organic solvent, it is preferable that they become -O- together.
In formula (4-6), R ²⁰⁸ and R ²⁰⁹ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.

In formula (4-6), R ²¹⁰ and R ²¹¹ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
In formula (4-6), Y ²¹ and Y ²² are each one of —C (═O) — and the other one is —CH ₂ — in terms of adhesion of the resist composition to the substrate surface and the like. It is preferable that
N9 in the formula (4-6) is preferably 0 in terms of dry etching resistance of the resist.

The structural unit (B) can be used alone or in combination of two or more.
The polymer (P) having the structural unit (B) can be produced by polymerizing a monomer containing the monomer (b) that gives the structural unit (B).
Examples of the monomer (b) include monomers represented by the following formulas (10-1) to (10-29). In formula (10-1) to formula (10-29), R represents a hydrogen atom or a methyl group.

Among these, the monomers represented by the formulas (10-1) to (10-3) and the formula (10-5), and their geometrical isomers and optical isomerism from the viewpoint of the sensitivity of the resist composition. The body is preferred. Further, in terms of resistance to dry etching of the resist, Formula (10-7), Formula (10-9), Formula (10-10), Formula (10-12), Formula (10-14), Formula (10−) The monomer represented by 24)-Formula (10-26) and Formula (10-29), and these geometrical isomers and optical isomers are preferable. Furthermore, in terms of solubility of the polymer (P) in an organic solvent, the formula (10-8), the formula (10-13), the formula (10-16) to the formula (10-23), and the formula (10- The monomer represented by 28) and geometrical isomers and optical isomers thereof are preferred.

Structural unit (C)

The structural unit (C) having an acid leaving group is a component that is soluble in an alkali by an acid, and has the effect of enabling the formation of a resist pattern. Therefore, it is used as a structural component of the polymer (P). Is preferred.
The content of the structural unit (C) is preferably 20 mol% or more and more preferably 25 mol% or more in the polymer (P) from the viewpoint of the sensitivity and resolution of the resist composition. Further, the content of the structural unit (C) is preferably 60 mol% or less, more preferably 55 mol% or less in the polymer (P), from the viewpoint of adhesion of the resist composition to the substrate surface or the like, The mol% or less is more preferable.

When the structural unit (C) has a lactone skeleton, the adhesiveness of the resist composition to the substrate tends to be good. In this case, the structural unit (C) also corresponds to the structural unit (B). However, in the present invention, such a structural unit is regarded as the structural unit (B).
Moreover, when the structural unit (C) has a hydrophilic group, the sensitivity of the resist composition tends to be more excellent. In this case, the structural unit (C) corresponds to the structural unit (D), but in the present invention, such a structural unit is regarded as the structural unit (C).

  As the structural unit (C), the following formula (3-1-1), formula (3-2-1), formula (3-3-1), formula (3-4) are used in terms of resist dry etching resistance. -1), formula (3-5-1), formula (3-6-1), formula (3-7-1) and at least one selected from the group consisting of formula (3-8-1) are preferred. .

In formulas (3-1-1) to (3-8-1), R ³¹ , R ³² , R ³³ , R ³⁴ , R ³⁵ , R ³⁶ , R ³⁷ and R ³⁸ are each independently a hydrogen atom or methyl Represents a group.
R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 3 carbon atoms.
X ¹ , X ² , X ³ , X ⁴ , X ⁵¹ and X ⁶¹ each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms.

n1, n2, n3, n4, n51 and n61 each independently represents an integer of 0 to 4. When n1, n2, n3, n4, n51 and n61 are 2 or more, X ¹ , X ² , X ³ , X ⁴ , X ⁵¹ and X ⁶¹ can each have a plurality of different groups.

R ³³¹ , R ³³² , R ³³³ , R ³³⁴ , R ³⁵¹ , R ³⁵² , R ³⁵³ , R ³⁵⁴ , R ³⁶¹ , R ³⁶² , R ³⁶³ and R ³⁶⁴ are each independently a hydrogen atom or a straight chain having 1 to 6 carbon atoms. Or represents a branched alkyl group.
V ¹ , V ² , V ³ , V ⁴ , V ⁵ and V ⁶ are each independently —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _u1 — ( u1 represents an integer of 1 to 6)).
q, q3, and q4 represent 0 or 1. r represents an integer of 0-2.

R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ each independently represent 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. And at least one of R ³⁵⁵ , R ³⁵⁶ and R ^{357 is} an alicyclic hydrocarbon group or a derivative thereof, or any two of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ are bonded to each other, The remaining one of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ that did not participate in the bond, together with the bonded carbon atom, formed a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof. 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.

R ³⁶⁷ and R ³⁷³ each independently represent 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 ³⁶⁵ , R ³⁶⁶ , R ³⁷¹ and R ³⁷² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or R ³⁶⁵ and R ³⁶⁷ , R ³⁶⁶ and R ³⁶⁷ , Two of R ³⁷¹ and R ³⁷³ or R ³⁷² and R ³⁷³ are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atoms to which they are bonded. , R ³⁶⁵ , R ³⁶⁶ , R ³⁷¹ and R ³⁷² , the remaining one not involved in the bond represents a hydrogen atom.
R ³⁸¹ , R ³⁸² and R ³⁸³ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms.

R1 in formula (3-1-1) is preferably a methyl group, an ethyl group or an isopropyl group from the viewpoint of the sensitivity and resolution of the resist composition.
N1 in Formula (3-1-1) is preferably 0 in terms of resistance to dry etching of the resist.

In formula (3-2-1), R ² and R ³ are each independently preferably a methyl group, an ethyl group or an isopropyl group from the viewpoint of sensitivity and resolution of the resist composition.
N2 in the formula (3-2-1) is preferably 0 in terms of dry etching resistance of the resist.

R ⁴ in formula (3-3-1) is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution of the resist composition.
V ¹ and V ^{2 in} Formula (3-3-1) are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the viewpoint of dry etching resistance of the resist.
R ³³¹ , R ³³² , R ³³³ and R ^{334 in} formula (3-3-1) are each independently a hydrogen atom, a methyl group, or an ethyl group in terms of solubility of the polymer (P) in an organic solvent. Or an isopropyl group is preferable.
N3 in Formula (3-3-1) is preferably 0 in terms of dry etching resistance of the resist.
Q in the formula (3-3-1) is preferably 1 from the viewpoint of dry etching resistance of the resist, and 0 is preferable from the viewpoint of solubility of the polymer (P) in an organic solvent.

R ⁵ in formula (3-4-1) is preferably a methyl group, an ethyl group or an isopropyl group from the viewpoint of the sensitivity and resolution of the resist composition.
N4 in Formula (3-4-1) is preferably 0 in terms of dry etching resistance of the resist.
In the formula (3-4-1), r is preferably 1 from the viewpoint of dry etching resistance of the resist, and 0 is preferable from the viewpoint of solubility of the polymer (P) in an organic solvent.

V ³ and V ^{4 in} formula (3-5-1) are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the standpoint of dry etching resistance of the resist.
R ³⁵¹ , R ³⁵² , R ³⁵³ and R ^{354 in} formula (3-5-1) are each independently a hydrogen atom, a methyl group, or an ethyl group in terms of solubility of the polymer (P) in an organic solvent. Or an isopropyl group is preferable.
N51 in Formula (3-5-1) is preferably 0 in terms of dry etching resistance of the resist.
Q3 in the formula (3-5-1) is preferably 1 from the viewpoint of dry etching resistance of the resist, and preferably 0 from the viewpoint of solubility of the polymer (P) in an organic solvent.
-C (R ³⁵⁵ ) (R ³⁵⁶ ) (R ³⁵⁷ ) in the formula (3-5-1) is a point of line edge roughness of the resist, and is expressed by the following formulas (K-1) to (K-6). The structure represented is preferable, and the structure represented by the following formulas (K-7) to (K-17) is preferable in terms of dry etching resistance of the resist.

In formula (3-6-1), V ⁵ and V ⁶ are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the viewpoint of dry etching resistance of the resist.
R ³⁶¹ , R ³⁶² , R ³⁶³ and R ^{364 in} formula (3-6-1) are each independently a hydrogen atom, a methyl group, or an ethyl group in terms of solubility of the polymer (P) in an organic solvent. Or an isopropyl group is preferable.
N61 in Formula (3-6-1) is preferably 0 in terms of resistance to dry etching of the resist.
Q4 in formula (3-6-1) is preferably 1 from the viewpoint of dry etching resistance of the resist, and preferably 0 from the viewpoint of solubility of the polymer (P) in an organic solvent.

-C (R ³⁶⁵ ) (R ³⁶⁶ ) -O-R ³⁶⁷ in the formula (3-6-1) is a point of line edge roughness of the resist, and the following formulas (J-1) to (J-24) The structure represented by the following formula (J-25) to the formula (J-52) is preferable from the viewpoint of dry etching resistance of the resist.

-C (R ³⁷¹ ) (R ³⁷² ) -O-R ³⁷³ in the formula (3-7-1) is a point of line edge roughness of the resist, and is represented by the formulas (J-1) to (J-24). The structure represented is preferable, and the structure represented by Formula (J-25) to Formula (J-52) is preferable in terms of dry etching resistance of the resist.
The structural unit (C) can be used alone or in combination of two or more.

The polymer having the structural unit (C) can be produced by polymerizing a monomer containing the monomer (c) that gives the structural unit (C).
Examples of the monomer (c) include monomers represented by the following formulas (9-1) to (9-224). In formula (9-1) to formula (9-224), R and R ′ each independently represent a hydrogen atom or a methyl group.

In addition to the above monomers, methoxymethyl (meth) acrylate and 1-ethoxyethyl (meth) acrylate may be mentioned.
Among these, in terms of the sensitivity and resolution of the resist composition, Formula (9-1) to Formula (9-3), Formula (9-5), Formula (9-16), and Formula (9-19) , Formula (9-20), Formula (9-22), Formula (9-23), Formula (9-25) to Formula (9-28), Formula (9-30), Formula (9-31), Monomers represented by the formula (9-33), the formula (9-34) and the formula (9-102) to the formula (9-129) and their geometrical isomers and optical isomers are preferable, and the formula (9 -1), formula (9-2), formula (9-16), formula (9-20), formula (9-23), formula (9-28), formula (9-31), formula (9- 34), Formula (9-109), Formula (9-111), Formula (9-114) to Formula (9-117), Formula (9-125), Formula (9-128), and Formula (9-129). ) Is more preferable.

  In terms of the line edge roughness of the resist, the equations (9-35) to (9-40), (9-52) to (9-62), and (9-76) to (9-) 88), formula (9-130) to formula (9-135), formula (9-147) to formula (9-157), and formula (9-171) to formula (9-183) And their geometric and optical isomers are preferred.

In terms of resistance to dry etching of the resist, the equations (9-41) to (9-51), the equations (9-63) to (9-75), and the equations (9-89) to (9- 101), formula (9-136) to formula (9-146), formula (9-158) to formula (9-170) and formula (9-184) to formula (9-196) And their geometric and optical isomers are preferred.
Moreover, the monomer represented by Formula (9-197)-Formula (9-224) and these geometrical isomers and optical isomers are more preferable at the point of the pattern rectangularity of a resist.

Structural unit (D)

The structural unit (D) having a hydrophilic group is preferably used as a structural unit of the polymer (P) because it has an effect of reducing the defect of the resist composition and improving the pattern rectangularity of the resist.
Examples of the hydrophilic group include —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a methoxy group, a carboxy group, and an amino group, which can be used alone or in combination of two or more.
The content of the structural unit (D) is preferably 5 to 30 mol%, more preferably 10 to 25 mol% in the polymer (P) in terms of the resist pattern rectangularity.

When the structural unit (D) has an acid leaving group, the sensitivity of the resist composition tends to be more excellent. In this case, the structural unit (D) corresponds to the structural unit (C), but in the present invention, such a structural unit is regarded as a structural unit (C) described later.
Moreover, when the structural unit (D) has a lactone skeleton, the sensitivity of the resist composition tends to be more excellent. In this case, the structural unit (D) corresponds to a structural unit (B) described later. In the present invention, such a structural unit is regarded as the structural unit (B).

  As the structural unit (D), for example, at least one selected from the group consisting of the following formulas (5-1) to (5-7) is preferable from the viewpoint of dry etching resistance of the resist.

In formula (5-1) to formula (5-7), R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ and R ⁵⁷ each independently represent a hydrogen atom or a methyl group.

R ⁵⁰¹ , R ⁵⁰² , R ⁵⁰³ , R ⁵⁰⁴ , R ⁵⁰⁵ and R ⁵⁰⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , X ⁵⁶ and X ⁵⁷ are each independently a linear or branched alkyl group having 1 to 6 carbon atoms, —C (CF ₃ ) ₂ —OH, a 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 esterified with an alcohol having 1 to 6 carbon atoms, or an amino group. The linear or branched alkyl group having 1 to 6 carbon atoms includes —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, and 1 to 1 carbon atoms as a substituent. It may have at least one group selected from the group consisting of a carboxy group and an amino group esterified with 6 alcohols.
Further, the position substituted by X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ and X ⁵⁶ may be any position in the cyclic structure.

n51, n52, n53, n54, n55 and n56 each independently represents an integer of 1 to 4. When n51, n52, n53, n54, n55 and n56 are 2 or more, X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ and X ⁵⁶ can each have a plurality of different groups.

R ^{531 to} R ⁵³⁶ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. 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 ) _u2 — (u2 represents an integer of 1 to 6). )).

  q1 and q2 represent 0 or 1. Moreover, r1 represents the integer of 0-2.

^R571 represents a carbon atom having a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms, or a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms. 1 to 6 linear or branched alkyl groups are represented.

R ⁵⁷² represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.
R ⁵⁷¹ and R ⁵⁷² may be combined to form a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms together with the carbon atom to which each is bonded.
Here, the alkyl group in R ⁵⁷¹ and R ⁵⁷² may have a hydroxy group, a carboxy group, an acyl group having 2 to 6 carbon atoms, or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms. Further, the bridged cyclic hydrocarbon group in R ⁵⁷¹ and R ⁵⁷² may have a linear or branched alkyl group having 1 to 6 carbon atoms, and the alkyl group is a hydroxy group, a carboxy group, 2 to 2 carbon atoms. It may have a carboxy group esterified with an acyl group of 6 or an alcohol having 1 to 6 carbon atoms.

R ⁵⁰¹ in formula (5-1) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
N51 in Formula (5-1) is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵¹ in formula (5-1) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.

N52 in Formula (5-2) is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵² in formula (5-2) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.

R ⁵⁰² in formula (5-3) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
In formula (5-3), W ¹ and W ² are each independently preferably —CH ₂ — or —CH ₂ CH ₂ — from the viewpoint of dry etching resistance of the resist.
R ⁵³¹ , R ⁵³² , R ⁵³³ and R ⁵³⁴ in the formula (5-3) are each independently a hydrogen atom, a methyl group, an ethyl group or a group having solubility in the organic solvent of the polymer (P). An isopropyl group is preferred.

N53 in Formula (5-3) is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵³ in formula (5-3) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.
Q1 in the formula (5-3) is preferably 1 from the viewpoint of dry etching resistance of the resist, and preferably 0 from the viewpoint of solubility of the polymer (P) in an organic solvent.

R ⁵⁰³ in the formula (5-4) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
In formula (5-4), n54 is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵⁴ in formula (5-4) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.
In formula (5-4), r1 is preferably 1 from the viewpoint of dry etching resistance of the resist, and 0 is preferable from the viewpoint of solubility of the polymer (P) in an organic solvent.

In formula (5-5), R ⁵⁰⁴ and R ⁵⁰⁵ are each independently preferably a methyl group, an ethyl group or an isopropyl group from the viewpoint of sensitivity and resolution of the resist composition.
N55 in Formula (5-5) is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵⁵ in formula (5-5) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.

R ⁵⁰⁶ in formula (5-6) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
W ³ in formula (5-6) is preferably —CH ₂ — or —CH ₂ CH ₂ — in terms of dry etching resistance of the resist.
In formula (5-6), R ⁵³⁵ and R ⁵³⁶ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.

N56 in the formula (5-6) is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵⁶ in formula (5-6) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.
Q2 in the formula (5-6) is preferably 1 from the viewpoint of dry etching resistance of the resist, and preferably 0 from the viewpoint of solubility of the polymer (P) in an organic solvent.

R ⁵⁷¹ and R ⁵⁷² in the formula (5-7) are, in terms of dry etching resistance of the resist, R ⁵⁷¹ and R ⁵⁷² are combined to form a carbon atom having 4 to 16 carbon atoms together with the carbon atom to which each is bonded. A structure in which a crosslinked cyclic hydrocarbon group is formed is preferable. In addition, in terms of heat resistance and stability of the polymer (P), R ⁵⁷¹ and R ⁵⁷² are combined and included in the bridged cyclic hydrocarbon group formed together with the carbon atoms to which they are bonded. Rings are camphor ring, adamantane ring, norbornane ring, pinane ring, bicyclo [2.2.2. It preferably has an octane ring, a tetracyclododecane ring, a tricyclodecane ring or a decahydronaphthalene ring.

X ⁵⁷ in the formula (5-7) is the point of the resist pattern shape, and is —CH ₂ —C (CF ₃ ) ₂ —OH, —CH ₂ —OH, —CH ₂ —CN, —CH ₂ —O. It is preferably —CH ₃ or — (CH ₂ ) ₂ —O—CH ₃ .
In the formulas (5-1) to (5-7), 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 (D) can be used alone or in combination of two or more.

The polymer having the structural unit (D) can be produced by polymerizing a monomer containing the monomer (d) that gives the structural unit (D).
Examples of the monomer (d) include monomers represented by the following formulas (13-1) to (13-79). In formula (13-1) to formula (13-79), R represents a hydrogen atom or a methyl group.

In addition to the above monomers, unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, itaconic acid and the like can be mentioned.
Among these, in terms of solubility of the polymer (P) in the resist solvent, the formula (13-1) to the formula (13-9), the formula (13-13) to the formula (13-16), and the formula (13-21) to formula (13-24), formula (13-30) to formula (13-34), formula (13-37) to formula (13-43), formula (13-56) to formula ( 13-59), Formula (13-62), Formula (13-63), Formula (13-66) to Formula (13-69), Formula (13-72), Formula (13-76) to Formula (13) -79) and the geometric isomers and optical isomers thereof are preferred.

Further, in terms of resistance to dry etching of the resist, the expressions (13-25) to (13-30), the expressions (13-44) to (13-55), the expressions (13-60), and (13- 61), monomers represented by formula (13-64), formula (13-65), formula (13-71), formula (13-73) to formula (13-75), and geometric isomers thereof And optical isomers are preferred.

Structural unit (E)

The polymer (P) of the present invention may contain other structural units (E) as necessary in addition to the structural units (B) to (D) described above.
Examples of the structural unit (E) include the structural unit (E1) having an alicyclic skeleton (nonpolar alicyclic skeleton) without having an acid-eliminable group and a hydrophilic group. Here, the alicyclic skeleton is a skeleton having one or more cyclic saturated hydrocarbon groups. The structural unit (E1) can be used alone or in combination of two or more.

The structural unit (E1) tends to exhibit an effect of expressing the dry etching resistance of the resist composition.
As the structural unit (E1), structural units represented by the following formulas (11-1) to (11-4) are preferable from the viewpoint of dry etching resistance of the resist.

In formula (11-1) to formula (11-4), R ³⁰¹ , R ³⁰² , R ³⁰³ and R ³⁰⁴ each independently represent a hydrogen atom or a methyl group.
X ³⁰¹ , X ³⁰² , X ³⁰³ and X ³⁰⁴ each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms, and the position at which they are bonded may be anywhere on the ring.
n301, n302, n303 and n304 each independently represents an integer of 0 to 4. Incidentally, n301, n302, if n303 and n304 is 2 or ^{more, X 301, X 302, X} 303 and X ³⁰⁴ may have a plurality of different groups.
p and p1 represent the integer of 0-2.

In addition, n301, n302, n303, and n304 are preferably 0 from the viewpoint of resist dry etching resistance.
p and p1 are preferably 0 in terms of solubility of the polymer (P) in an organic solvent, and 1 is preferably in terms of dry etching resistance of the resist.

The polymer (P) containing the structural unit (E1) can be produced by polymerizing a monomer containing the monomer (e1) having a nonpolar alicyclic skeleton.
Examples of the monomer (e1) include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentadienyl ( Meth) acrylates and derivatives having a linear or branched alkyl group having 1 to 6 carbon atoms on the alicyclic skeleton of these compounds are preferred.
Examples of the monomer (e1) include monomers represented by the following formulas (14-1) to (14-5). In formula (14-1) to formula (14-5), R represents a hydrogen atom or a methyl group.
In addition to the above monomers, those having a cycloolefin structure such as norbornene as the alicyclic skeleton can be mentioned.

The polymer (P) may further contain a structural unit (E2) other than the above.
The polymer containing the structural unit (E2) can be produced by polymerizing a monomer containing the monomer (e2).

  Examples of the monomer (e2) include methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) ) Acrylate, isobutyl (meth) acrylate, n-propoxyethyl (meth) acrylate, iso-propoxyethyl (meth) acrylate, n-butoxyethyl (meth) acrylate, iso-butoxyethyl (meth) acrylate, tert-butoxyethyl ( (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy-n-propyl (meth) acrylate, 4-hydroxy-n-butyl (meth) acrylate, 2- Toxiethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoro-n-propyl (meth) acrylate, 2,2,3,3,3-penta Fluoro-n-propyl (meth) acrylate, methyl 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 α- (tri) fluoromethyl Acrylate, methoxymethyl α- (tri) fluoromethyla Relate, ethoxyethyl α- (tri) fluoromethyl acrylate, n-propoxyethyl α- (tri) fluoromethyl acrylate, iso-propoxyethyl α- (tri) fluoromethyl acrylate, n-butoxyethyl α- (tri) fluoromethyl (Meth) acrylates having a linear or branched structure such as acrylate, iso-butoxyethyl α- (tri) fluoromethyl acrylate, tert-butoxyethyl α- (tri) fluoromethyl acrylate; styrene, α-methylstyrene, vinyltoluene P-hydroxystyrene, p-tert-butoxycarbonylhydroxystyrene, 3,5-di-tert-butyl-4-hydroxystyrene, 3,5-dimethyl-4-hydroxystyrene, p-tert-perfluorobutylstyrene , Aromatic alkenyl compounds such as p- (2-hydroxy-iso-propyl) styrene; unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; ethylene, propylene, norbornene, tetrafluoroethylene, acrylamide, N -Methylacrylamide, N, N-dimethylacrylamide, vinyl chloride, vinyl fluoride, vinylidene fluoride and vinylpyrrolidone.

The content of the structural unit (E) is preferably 20 mol% or less in the polymer.

Polymer (P)

The mass average molecular weight of the polymer (P) is preferably 2,000 or more, more preferably 3,000 or more, particularly preferably 4,000 or more, and 5,000 or more in terms of dry etching resistance and pattern shape of the resist. Is more preferable. In addition, the mass average molecular weight of the polymer (P) is preferably 100,000 or less, more preferably 50,000 or less, in terms of the solubility of the polymer (P) in an organic solvent and the resolution of the resist composition. 30,000 or less is particularly preferable, and 20,000 or less is more preferable.
The molecular weight distribution of the polymer (P) is preferably 2.5 or less, more preferably 2.0 or less, more preferably 1.8 or less in terms of the solubility of the polymer (P) in an organic solvent and the resolution of the resist composition. The following are particularly preferred:

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

Method for producing polymer (P)

As a method for producing the polymer (P), known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. Among these, solution polymerization is preferable because a polymer having a relatively low molecular weight is easily obtained.
The solution polymerization may be batch polymerization or dropping polymerization, but dropping polymerization in which a monomer is dropped into a polymerization vessel is preferable in that a polymer having a narrow composition distribution and / or molecular weight distribution can be obtained easily. The monomer to be dropped may be either a monomer alone or a solution obtained by dissolving the monomer in an organic solvent.

As the dropping polymerization method, for example, an organic solvent is charged in a polymerization vessel in advance (hereinafter, this organic solvent is referred to as “charged solvent”), heated to a predetermined polymerization temperature, and then a monomer or a polymerization initiator is used alone or A method in which a solution dissolved in an organic solvent in any combination (hereinafter, this organic solvent is referred to as “dropping solvent”) is charged and dropped into the solvent.
The dropping method is not limited to this. The monomer can also be dropped without dissolving in the dropping solvent, and in that case, the polymerization initiator can be dissolved in the monomer or in the dropping solvent. Moreover, a monomer and a polymerization initiator can be dripped in the polymerization container in which the preparation solvent does not exist.
The monomer and the polymerization initiator may be dropped directly from an independent storage tank into a charged solvent heated to a predetermined polymerization temperature, or mixed just before dropping and dropped into the charged solvent. Good.
Further, a part of the monomer may be charged in advance into the polymerization vessel together with the charged solvent.

Furthermore, as a method of charging the monomer and the polymerization initiator and dropping them into the solvent, a method of dropping the monomer first and then dropping the polymerization initiator, a monomer after dropping the polymerization initiator first, Either the dropping method or the dropping method of the monomer and the polymerization initiator at the same timing may be used.
In addition, these dropping speeds are a constant speed until the end of dropping, a method of changing the speed in multiple steps according to the consumption speed of the monomer and the polymerization initiator, or a method of intermittently stopping / implementing the dropping. Either of these may be used.
The polymerization temperature in the drop polymerization method is preferably 50 to 150 ° C.

As an organic solvent (hereinafter referred to as “polymerization solvent”) used in the dropping polymerization, a known solvent can be used. Specific examples of the polymerization solvent include linear or branched ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, and 2-hexanone; cyclic ketones such as cyclopentanone and cyclohexanone; N, N Amides such as dimethylacetamide and N, N-dimethylformamide; Sulfoxides such as dimethyl sulfoxide; Chain ethers such as diethyl ether and propylene glycol monomethyl ether; Ethers such as tetrahydrofuran and cyclic ethers such as 1,4-dioxane Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ethylene glycol monomethyl ether acetate, ethyl Ethylene glycol monoalkyl ether acetates such as ethylene glycol monoethyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether Alkyl ethers; diethylene glycol alkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol monomethyl ether; esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate and γ-butyrolactone; n-propyl alcohol , Isopropyl alcohol, n-butyl alcohol Alcohols such as alcohol, cyclohexanol, 1-octanol; pentane, 2-methylbutane, n-hexane, 2-methylpentane, 2,2-dibutylbutane, 2,3-dibutylbutane, n-heptane, n-octane, C5-C11 aliphatic hydrocarbons such as isooctane, 2,2,3-trimethylpentane, n-nonane, 2,2,5-trimethylhexane, n-decane, n-dodecane, benzene, toluene, xylene, etc. Aromatic hydrocarbons, hydrocarbons such as cycloaliphatic hydrocarbons such as cyclohexane; 1,4-dioxane and ethylene carbonate.
Among these, a hydroxyl group-containing ester such as ethyl lactate is preferable when obtaining a low molecular weight polymer.
These solvents can be used alone or in combination of two or more.

The amount of the polymerization solvent used is usually 30 to 700 parts by mass with respect to 100 parts by mass of the total amount of monomers used for the polymerization.
In the dropping polymerization method, when two or more kinds of polymerization solvents are used, the mixing ratio of the polymerization solvent in the dropping solvent and the charged solvent can be set at an arbitrary ratio.
The monomer concentration of the monomer solution dropped into the polymerization solvent is preferably 5 to 50% by mass.
The amount of the charged solvent is usually 30 to 700 parts by mass with respect to 100 parts by mass of the total amount of monomers used for the polymerization.

  As the polymerization initiator, those that generate radicals efficiently by heat are preferable. Examples of such a polymerization initiator include 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 2,2′-azobis [2- (2-imidazoline- Azo compounds such as 2-yl) propane]; organic peroxides such as 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane and di (4-tert-butylcyclohexyl) peroxydicarbonate Is mentioned.

When the polymer (P) is used for lithography using an ArF excimer laser (wavelength: 193 nm), the light transmittance to the polymer (P) (transmittance with respect to light having a wavelength of 193 nm) is not reduced as much as possible. As the polymerization initiator, those having no aromatic ring in the molecular structure are preferably used. Among these, dimethyl-2,2′-azobisisobutyrate is preferable from the viewpoint of the sensitivity of the resist composition.
Furthermore, in consideration of safety during polymerization, the polymerization initiator preferably has a 10-hour half-life temperature of 60 ° C. or higher.

  In order to increase the yield of the polymer (P), the amount of the polymerization initiator used is preferably 0.3 mol parts or more, preferably 1 mol parts or more with respect to 100 mol parts of the total amount of monomers used for polymerization. More preferred. The amount of the polymerization initiator used is preferably 30 parts by mole or less with respect to 100 parts by mole of the total amount of monomers used for polymerization in order to narrow the molecular weight distribution of the polymer (P).

When the polymer (P) is used for lithography, a chain transfer agent may be used as long as the storage stability of the resist composition is not hindered.
Examples of chain transfer agents include 1-butanethiol, 2-butanethiol, 1-octanethiol, 1-decanethiol, 1-tetradecanethiol, cyclohexanethiol, 2-methyl-1-propanethiol, and 2-hydroxyethyl mercaptan. Is mentioned.
When used in a lithography application using an ArF excimer laser (wavelength: 193 nm), the chain transfer agent is an aromatic substance so as not to reduce the light transmittance to the polymer (P) as much as possible (transmittance to light having a wavelength of 193 nm). Those having no ring are preferred.

The polymer solution produced by solution polymerization is diluted with a solvent for polymerization to an appropriate solution viscosity, if necessary, and then in a large amount of poor solvent (deposition solvent) such as methanol, water, hexane, heptane, etc. The polymer (P) can be precipitated by dropping.
The precipitation of the polymer (P) is very effective for removing unreacted monomers and polymerization initiators remaining in the polymer 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 precipitate of the polymer (P) can be obtained as a powder of the polymer (P) by filtering and drying as necessary.
Further, after the precipitation, the solution can be separated by filtration, and subsequently redissolved in a solvent, and the redissolved solution is sequentially concentrated to obtain a polymer (P) solution.

Resist composition

The resist composition of the present invention contains a polymer (P).
The resist composition of the present invention can be prepared by dissolving the polymer (P) in a solvent. Moreover, this polymer solution can also be used for preparation of a resist composition as it is, without isolate | separating a polymer from the polymer solution obtained by solution polymerization etc. Further, the polymer solution can be diluted with an appropriate solvent or concentrated to be used for preparing a resist composition.
In addition, after dropping the polymer (P) solution into a poor solvent and precipitating the polymer (P) to separate the polymer, the resist composition is prepared as a wet powder without drying. Can also be used. Furthermore, after the polymer powder is dissolved in a suitable solvent, the concentrated polymer solution can be used for the preparation of a resist composition.

Examples of the solvent include the same solvents as those for polymerization. These solvents can be used alone or in combination of two or more.
These solvents can be used alone or in combination of two or more.
Among these, propylene glycol monomethyl ether acetate, ethyl lactate, cyclohexanone and γ-butyrolactone are preferable from the viewpoint of safety.

The content of the solvent is usually 200 to 5000 parts by mass, more preferably 300 to 2000 parts by mass with respect to 100 parts by mass of the polymer.

Chemically amplified resist composition

When the resist composition of the present invention is a chemically amplified resist composition, the resist composition further contains a photoacid generator.

Photoacid generator

  The photoacid generator can be arbitrarily selected from those that can be used as an acid generator of a chemically amplified resist composition.

Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, sulfone compounds, sulfonate ester compounds, quinonediazide compounds, and diazomethane compounds.
Of these, onium salt compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like are preferable.
Specific examples include triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate. , Diphenyliodonium hexafluoroantimonate, p-methylphenyldiphenylsulfonium nonafluorobutanesulfonate, and tri (tert-butylphenyl) sulfonium trifluoromethanesulfonate.

The photoacid generator can be used alone or in combination of two or more.
Although content of a photo-acid generator is suitably determined by the kind of photo-acid generator, 0.1 mass part or more is preferable with respect to 100 mass parts of polymers (P), and 0.5 mass part or more is more preferable. 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, 20 mass parts or less are preferable with respect to 100 mass parts of polymers (P), and, as for content of a photo-acid generator, 10 mass parts or less are more preferable. By making 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 resist composition and scum during development of the resist composition is reduced. .

  The resist composition of the present invention may further contain a nitrogen-containing compound. By containing the nitrogen-containing compound, the resist pattern shape, the stability over time, and the like are improved. That is, the cross-sectional shape of the resist pattern becomes closer to a rectangle, and when the resist film is exposed, post-exposure baked (PEB), and left for the next development process, the cross-sectional shape of the pattern is deteriorated. Is more suppressed.

Known compounds can be used as the nitrogen-containing compound, but amines are preferable, and 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 and triethanolamine. Can be mentioned. Of these, tertiary alkanolamines such as triethanolamine are more preferred.

The nitrogen-containing compounds can be used alone or in combination of two or more.
Although content of a nitrogen-containing compound is suitably determined by the kind etc. of nitrogen-containing compound, 0.01 mass part or more is preferable with respect to 100 mass parts of polymers (P). By setting the content of the nitrogen-containing compound within this range, the pattern shape of the resist can be made more rectangular.
Further, the content of the nitrogen-containing compound is preferably 2 parts by mass or less with respect to 100 parts by mass of the polymer (P). By setting the content of the nitrogen-containing compound within this range, it is possible to reduce the sensitivity deterioration of the resist composition.

The resist composition of the present invention can further contain an organic carboxylic acid, an oxo acid of phosphorus, or a derivative thereof. By containing these compounds, the sensitivity deterioration of the resist composition due to the blending of the nitrogen-containing compound can be prevented, and the resist pattern shape and the stability over time are further improved.
As the organic carboxylic acid, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid and salicylic acid are preferable.
Examples of phosphorus oxo acids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and the like; and phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid di- Examples thereof include phosphonic acids such as n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester, and ester derivatives thereof; phosphinic acids such as phosphinic acid and phenylphosphinic acid, and ester derivatives thereof. Of these, phosphonic acid is preferred.
The organic carboxylic acid or phosphorus oxo acid or derivative thereof can be used alone or in combination of two or more.

The content of the organic carboxylic acid or phosphorus oxo acid or derivative thereof is appropriately determined depending on the type of the compound and the like, but is preferably 0.01 parts by mass or more per 100 parts by mass of the polymer (P). By setting the content of the organic carboxylic acid or phosphorus oxo acid or derivative thereof within this range, the pattern shape of the resist can be made more rectangular.
The content of the organic carboxylic acid or phosphorus oxo acid or derivative thereof is preferably 5 parts by mass or less with respect to 100 parts by mass of the polymer (P). By setting the content of the organic carboxylic acid or phosphorus oxo acid or derivative thereof within this range, the film loss of the resist pattern can be reduced.

  The chemically amplified resist composition of the present invention may contain both a nitrogen-containing compound and an organic carboxylic acid or phosphorus oxo acid or a derivative thereof.

  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, what is necessary is just to determine the compounding quantity of these additives suitably.

In the present invention, the substrate on which the pattern has been formed is a step of forming a resist film on the substrate with the resist composition of the present invention, a step of exposing the resist composition with light having a wavelength of 250 nm or less, and developing the resist film with a developer. It is obtained with the manufacturing method including a process.

substrate

Examples of the substrate include a silicon wafer that forms a pattern.

Resist film

The resist film is obtained by applying a resist composition to the surface of a substrate by spin coating or the like and drying it by baking (pre-baking) or the like.
The film thickness of the resist film is 0.02 to 3 μm.

exposure

Exposure (irradiation of radiation) is performed through a photomask.
As radiation used for exposure, for example, an electron beam or light having a wavelength of 250 nm or less is used, and ultraviolet rays such as i-line and g-line, KrF excimer laser, ArF excimer laser, F ₂ excimer laser or EUV excimer laser are preferable.
Further, in the present invention, a high refractive index liquid such as pure water, perfluoro-2-butyltetrahydrofuran, perfluorotrialkylamine, perhydronaphthalene, perhydropyrene is provided between the resist film and the final lens of the exposure apparatus. Immersion exposure may be performed in which exposure is performed with the intervening layer interposed.
In the case of a resist composition for immersion exposure in semiconductor production, an ArF excimer laser is preferred.

developing

After exposure, heat treatment (post exposure bake (PEB)) and then development. As a development method, the substrate is immersed in an alkaline developer, and the exposed portion is dissolved and removed with a developer in the case of a chemically amplified resist, and the unexposed portion in the case of a resist not containing a photoacid generator. A method is mentioned. Known alkali developers can be used.

Method for manufacturing a substrate on which a pattern is formed

Hereinafter, an example of a method for manufacturing a substrate on which a pattern is formed will be described.
First, a resist composition is applied to the surface of the substrate by spin coating or the like. Next, the substrate coated with the resist composition is dried by baking (pre-baking) or the like to obtain a resist film on the substrate.
Thereafter, the resist film is exposed through a photomask with an immersion liquid interposed between the resist film and the final lens of the exposure apparatus as necessary.
After the exposure, it is heat-treated and then developed. After development, the resist pattern is obtained on the substrate by rinsing the substrate with pure water or the like.
The substrate on which the resist pattern is formed is reinforced by heat treatment (post-bake). Thereafter, the resist-free portion on the substrate is selectively etched. After etching, the resist is removed with a release agent to obtain a substrate on which a pattern is formed.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In each example and comparative example, “parts” and “%” represent “parts by mass” and “% by mass”, respectively, unless otherwise specified.
Moreover, the polymer and the resist composition were evaluated by the following methods.

1. Evaluation of polymer <content of each constituent unit of polymer>
The content of the constituent units of the polymer, in the case where it can be determined by the ¹ H-NMR measurement was determined by ¹ H-NMR measurement. Further, when it could not be determined by ¹ H-NMR measurement due to proton peak overlap or the like, it was determined by ¹³ C-NMR measurement.
JNM-GX-270 type FT-NMR (trade name) manufactured by JEOL Ltd. was used for ¹ H-NMR measurement. About 5% of a polymer sample in a deuterated chloroform solution or a deuterated dimethyl sulfoxide solution was put in a test tube having a diameter of 5 mmφ, and measurement was carried out 64 times in an observation frequency of 270 MHz and a single pulse mode. The measurement temperature was 40 ° C. when deuterated chloroform was used as the solvent, and 60 ° C. when deuterated dimethyl sulfoxide was used as the solvent.
^{For 13} C-NMR measurement, UNITY-INOVA type FT-NMR (trade name) manufactured by Varian Technologies was used. About 20% polymer sample deuterated dimethyl sulfoxide solution was put into a test tube with a diameter of 5 mmφ, and the proton complete decoupling method with a measurement temperature of 60 ° C., an observation frequency of 125 MHz, and a nuclear overhauser effect (NOE) removed. Measurements were performed with 50,000 integrations.

<Mass average molecular weight and molecular weight distribution>
About 20 mg of the polymer was dissolved in 5 ml of tetrahydrofuran (hereinafter referred to as “THF”) and filtered through a 0.5 μm membrane filter to prepare a sample solution. The mass average molecular weight and molecular weight distribution of this sample solution were measured by using gel permeation chromatography (GPC) manufactured by Tosoh Corporation.
In addition, the separation column used the Showa Denko Co., Ltd. product and three Shodex GPC K-805L (brand name) in series. In the measurement, THF was used as a solvent, and a differential refractometer was used as a detector. The measurement was performed at a flow rate of 1.0 ml / min, a measurement temperature of 40 ° C., and an injection amount of 0.1 ml, and polystyrene was used as a standard polymer.

<Light transmittance>
5 parts of a resist polymer and 45 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMEA”) as a solvent were mixed to obtain a uniform solution. This was filtered through a membrane filter having a pore size of 0.1 μm to prepare a polymer solution.
Next, the polymer solution was spin-coated on a quartz wafer as a substrate, and prebaked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 1 μm.
The resist film produced on the quartz wafer was installed on the sample side of the UV-3100 (trade name) made by Shimadzu Corporation, and the untreated quartz wafer was placed on the reference side. The light transmittance was measured. In the measurement, the wavelength range was 192 to 194 nm, the scan speed was medium, the sampling pitch was automatic, and the slit width was 2.0.

2. Evaluation of resist composition <Preparation of resist composition>
A homogeneous solution was prepared by mixing 100 parts of a polymer (solid), 2 parts of triphenylsulfonium triflate as a photoacid generator, and 720 parts of PGMEA and 180 parts of ethyl lactate as a solvent. Thereafter, this solution was filtered through a membrane filter having a pore size of 0.1 μm to prepare a resist composition.

<Creation of resist pattern>
The prepared resist composition 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 0.3 μm. Next, after exposure using an ArF excimer laser exposure machine (wavelength: 193 nm) using a 0.16 μm line and space pattern mask, post-exposure baking was performed at 110 ° C. for 60 seconds using a hot plate. . Thereafter, development was performed at room temperature using a 2.38% tetramethylammonium hydroxide aqueous solution, washed with pure water, and dried to form a resist pattern.

<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.

<Defect amount>
With respect to the resist pattern obtained above, the number of development defects was measured using a surface defect observation apparatus KLA2132 (trade name) manufactured by KLA Tencor and used as the defect amount. The measurement was carried out in a 18.0 cm ² range in which a 0.16 μm line and space pattern was formed on a 6-inch wafer.

<Focus depth of focus>
The resist film on the silicon wafer obtained by the above method has an optimum exposure amount for a 0.16 μm line-and-space pattern, and a focal depth from −1.0 μm to +1.0 μm in increments of 0.1 μm. The resist pattern was observed with a JSM-6340F field emission scanning electron microscope (trade name) manufactured by JEOL Ltd., and the pattern line width was 0.144 μm (−10%) to 0. The range (μm) that becomes 176 μm (+ 10%) was defined as the focal depth margin.

<Dry etching resistance>
A silicon wafer coated with a resist film having a film thickness of 0.3 μm before exposure, obtained in the same manner as in the sensitivity measurement, was manufactured by Showa Vacuum Co., Ltd., SPE-220T type dry etching apparatus (trade name) ) Was dry-etched.
The processing conditions were such that the gas type and gas flow rate were CF ₄ / O ₂ = 95 sccm / 5.0 sccm, the processing chamber pressure was 15 Pa, the plasma power was 400 W, and the processing time was 2 minutes.
The film thickness of the resist film before and after the dry etching treatment was measured using a Lambda Ace VM-8000J type optical interference type film thickness measuring device (trade name) manufactured by Dainippon Screen Mfg. Co., Ltd.
As a measuring method, the film thickness of a total of five points of the wafer center and the points moved 25 mm up, down, left and right from the center was measured, and the average value thereof was defined as the resist film thickness.
The film thickness (T) before and after the dry etching treatment of the sample, the film thickness (t) after the treatment, and the film thickness (T ₀ ) and the treatment before the dry etching treatment of the polymer obtained in Comparative Example 1 to be described later. A value (ER) represented by the following formula was calculated from the subsequent film thickness (t ₀ ), and dry etching resistance was evaluated. The smaller this value, the better the dry etching resistance.
ER = (T−t) / (T ₀ −t ₀ )

[ Reference Example 1]
After adding 71.9 parts of ethyl lactate to a flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer at room temperature, nitrogen was blown into the ethyl lactate for 30 minutes using a ball filter. Thereafter, the temperature in the flask was raised to 80 ° C. while stirring in a nitrogen atmosphere.
Subsequently, 26.5 parts of α-methacryloyloxy-γ-butyrolactone (hereinafter referred to as “GBLMA”) represented by the formula (51), 2-methacryloyloxy-2-methyladamantane represented by the following formula (52) ( Hereinafter, 32.8 parts (hereinafter referred to as “MAdMA”), 9.4 parts of 1-methacryloyloxy-3-hydroxyadamantane (hereinafter referred to as “HAdMA”) represented by the following formula (53), and represented by the following formula (54) 17.5 parts of 2-methacryloyloxyethoxy-6-hydroxynaphthalene (hereinafter referred to as “HNEMA”), 129.4 parts of ethyl lactate and dimethyl-2,2′-azobisisobutyrate (hereinafter referred to as “DAIB”) A monomer solution in which 2.21 parts were mixed was prepared. This monomer solution was put into a dropping device and dropped into the flask at a constant rate over 4 hours. After completion of dropping, the mixture was kept at an internal temperature of 80 ° C. for 3 hours to obtain a polymer (A-1) solution.

  Subsequently, the polymer (A-1) solution was dropped into a mixed solvent of methanol / water = 80/20 (volume%) about 10 times as much as the stirring state as a precipitation solvent to obtain a white precipitate. After the precipitate was filtered off, it was again poured into a mixed solvent of about 10 times the amount of methanol / water = 90/10 (volume%) as a washing solvent, and the precipitate was washed with stirring. Thereafter, the precipitate was filtered off and dried at 60 ° C. under reduced pressure for about 40 hours. The obtained polymer (A-1) was evaluated, and the results are shown in Table 1.

[ Reference Example 2]
The initial amount of ethyl lactate in the flask was 72.6 parts, and the monomer solution in the dropping apparatus was 8-acryloyloxy-4-oxatricyclo [5.2.2.1.02] represented by the following formula (55). , 6] decan-3-one 50% and 9-acryloyloxy-4-oxatricyclo [5.2.1.02,6] decan-3-one 50% mixture (hereinafter referred to as “OTDA”) 28.4 parts, ethyl cyclohexyl methacrylate (hereinafter referred to as “ECHMA”) represented by the following formula (56) 32.1 parts, 2- and 3-cyano-5-norbol represented by the following formula (57) Nyl methacrylate (hereinafter referred to as “CNNMA”) 13.1 parts, 2-methacryloyloxy (1-hydroxymethylethoxy) -6-hydroxynaphthalene (hereinafter referred to as “HNGMA”) 13 represented by the following formula (58) 4 parts, and a monomer solution obtained by mixing 130.6 parts of ethyl lactate and DAIB1.66 parts. Other conditions were the same as in Reference Example 1 to obtain a polymer (A-2) solution.

Subsequently, methanol / water = 80/20 (volume%) was changed to methanol as a precipitation solvent, and methanol / water = 90/10 (volume%) was changed to methanol as a washing solvent. Other conditions were the same as in Reference Example 1, precipitation, filtration, and drying to obtain a polymer (A-2). The obtained polymer (A-2) was evaluated and the results are shown in Table 1.

[Example 3]
The initial charged ethyl lactate in the flask was 75.6 parts, and the monomer solution in the dropping apparatus was 39.0 parts of 2-adamantyloxymethyl methacrylate (hereinafter referred to as “AdOMMA”) represented by the following formula (59). 13.5 parts of 2-methacryloyloxy-2-cyanomethyladamantane (hereinafter referred to as “CMMAMA”) represented by the following formula (60), 2-methacryloyloxy (1-hydroxy) represented by the following formula (61) Monomer obtained by mixing 9.7 parts of methylethoxy) -6- (tert-butoxycarbonyloxy) naphthalene (hereinafter referred to as “BONGMA”), 28.6 parts of GBLMA, 136.1 parts of ethyl lactate and 5.52 parts of DAIB It was set as the solution. Other conditions were the same as in Reference Example 1 to obtain a polymer (A-3) solution.

Subsequently, methanol was changed to methanol / water = 90/10 (volume%) as a precipitation solvent. Other conditions were the same as in Reference Example 2, precipitation, filtration, and drying to obtain a polymer (A-3). The obtained polymer (A-3) was evaluated, and the results are shown in Table 1.

[ Reference Example 4]
The initial charged ethyl lactate in the flask was 77.5 parts, and the monomer solution in the dropping apparatus was 1- (1-methacryloyloxy-1-methylethyl) adamantane (hereinafter, “ 40.9 parts) (referred to as "IAdMA"), 2-methacryloyloxyethoxy-6- (ethylcyclopentyloxycarbonylmethyl) naphthalene (hereinafter referred to as "EPNEMA") represented by the following formula (63), OTDA 29.3 Part, HAdMA 15.1 parts, HNEMA 7.7 parts, ethyl lactate 139.4 parts and DAIB 4.14 parts were mixed. Other conditions were the same as in Reference Example 1 to obtain a polymer (A-4) solution.

  Then, precipitation, filtration and drying were conducted in the same manner as in Example 3 to obtain a polymer (A-4). The obtained polymer (A-4) was evaluated, and the results are shown in Table 1.

[ Reference Example 5]
The initial charged ethyl lactate in the flask was 71.7 parts, and the monomer solution in the dropping apparatus was 1-methacryloyloxyethoxy-5- (ethylcyclohexyloxycarbonylmethyl) naphthalene (hereinafter referred to as the following formula (64)). , 15 “EHNEMA”) 11.9 parts, GBLMA 22.4 parts, MAdMA 36.5 parts, HAdMA 15.1 parts, ethyl lactate 129.0 parts and DAIB 2.58 parts. Other conditions were the same as in Reference Example 1 to obtain a polymer (A-5) solution.

  Next, precipitation, filtration and drying were conducted in the same manner as in Example 3 to obtain a polymer (A-5). The obtained polymer (A-5) was evaluated, and the results are shown in Table 1.

[Comparative Example 1]
The initial amount of ethyl lactate in the flask was 68.9 parts, and the monomer solution in the dropping apparatus was 29.2 parts GBLMA, 39.3 parts MAdMA, 14.2 parts HAdMA, 124.1 parts ethyl lactate, and 2.58 parts DAIB. A mixed monomer solution was obtained. Other conditions were the same as in Reference Example 1 to obtain a polymer (B-1) solution.
Subsequently, precipitation, filtration separation and drying were performed in the same manner as in Reference Example 1 to obtain a polymer (B-1). The obtained polymer (B-1) was evaluated, and the results are shown in Table 1.

[Comparative Example 2]
5. The initial charged ethyl lactate in the flask is 69.5 parts, and the monomer solution in the dropping apparatus is 2-vinyl-6-hydroxynaphthalene (hereinafter referred to as “HVN”) represented by the following formula (65). A monomer solution in which 8 parts, 27.2 parts of GBLMA, 37.4 parts of MAdMA, 9.4 parts of HAdMA, 125.0 parts of ethyl lactate and 2.76 parts of DAIB were mixed. Other conditions were the same as in Reference Example 1 to obtain a polymer (B-2) solution.

Subsequently, precipitation, filtration separation and drying were performed in the same manner as in Reference Example 2 to obtain a polymer (B-2). The obtained polymer (B-2) was evaluated, and the results are shown in Table 1.

As is clear from Table 1, the polymer of Example 3 was excellent in light transmittance. In addition, the resist composition of Example 3 had sufficient sensitivity and resolution, and had few defects. In addition, the resist has a wide focal depth margin and excellent dry etching resistance.
In contrast, the resist compositions of Comparative Examples 1 and 2 were inferior in resolution and had many defects. In addition, the resist has a narrow depth of focus margin, and dry etching.

Claims (3)

A resist polymer comprising a structural unit (A-2) having a naphthalene skeleton represented by the following formula (1-2) and a structural unit represented by the following formula (5-1) .
In formula (1-2), R ¹⁰ represents a hydrogen atom or a methyl group. Y represents —CH ₂ —C (═O) —OH, —OH, —CH ₂ —C (═O) —OR ¹³ or —OR ¹³ . R ¹³ represents a linear, branched or cyclic hydrocarbon group having 1 to 20 carbon atoms. This hydrocarbon group may have a hetero atom.
L ^{1 is-} (C (R ²⁰¹ ) (R ²⁰² ) -C (R ²⁰³ ) (R ²⁰⁴ ) -O) _k1-or- (C (R ²¹¹ ) (R ²¹² ) -C (R ²¹³ ) (R ²¹⁴ ) -C (R ²¹⁵ ) (R ²¹⁶ ) -O) _k2- . R ²⁰¹ to R ²⁰⁴ and R ²¹¹ to R ²¹⁶ are each independently a hydrogen atom, a straight-chain or branched hydrocarbon group having 1 to 3 carbon atoms.
This hydrocarbon group may have a hetero atom. k1 and k2 each independently represent an integer of 1 to 3.
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵⁰¹ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
X ⁵¹ represents a cyano group or a linear or branched alkyl group having 1 to 6 carbon atoms having at least one cyano group. Further, the position substituted with X ⁵¹ may be any position in the cyclic structure.
n51 represents an integer of 1 to 4. When n51 is 2 or more, X ⁵¹ can have a plurality of different groups. A resist composition comprising the polymer according to claim 1. 3. Production of a substrate on which a pattern having a step of applying a resist composition according to claim 2 on a substrate to form a resist film, a step of exposing with light having a wavelength of 250 nm or less and a step of developing with a developer. Method.