JP5138199B2 - Resist polymer, resist composition, and method for producing substrate with pattern - 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 fine processing 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 method for miniaturization, generally, the irradiation light has a shorter wavelength, and specifically, from conventional ultraviolet rays typified by g-line (wavelength: 438 nm) and i-line (wavelength: 365 nm). The irradiation light is changing to a 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 for further shortening the wavelength have been studied. ing. 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 a high-resolution resist using such 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. It has been.
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 an acrylic resin, for example, a polymer of (meth) acrylic acid ester having an adamantane skeleton in the ester portion and a polymer of (meth) acrylic acid ester having a lactone skeleton in the ester portion is disclosed in Patent Document 1, Patent Document 2, and the like. Is disclosed.

However, when these acrylic resins are used as a resist composition, a development defect called a defect may occur during development with an alkaline developer for producing a resist pattern. Then, due to this defect, the resist pattern may be missing, causing circuit disconnection, defects, and the like, which may lead to a decrease in yield in the semiconductor manufacturing process.
In addition, the sidewall roughness (also referred to as line edge roughness) of the resist pattern may be large, and as with defects, circuit breaks or defects may occur, leading to a decrease in yield in the semiconductor manufacturing process.
Furthermore, there is a concern that the dry etching resistance is insufficient due to the thin film thickness of the resist.

When these acrylic resins are used as a resist composition for immersion, the refractive index of the resist composition may be lower than that of the immersion liquid, and excimer laser light is totally reflected by the resist composition. There is a possibility that the resist pattern itself cannot be formed. In addition, when the immersion liquid is pure water, the contact between the pure water and the resist composition may cause defects more easily than in lithography in a dry environment.
On the other hand, a polymer having a heteroaromatic ring is disclosed in Patent Document 3, Patent Document 4, and the like.
However, although these resins are excellent in 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 not sufficient, or the coexistence with other monomers. In many cases, the polymerizability is not sufficient, which may adversely affect sensitivity and resolution.
JP 10-319595 A JP-A-10-274852 JP 2005-114968 A JP 2004-163877 A

  The present invention is a dry etching that has high sensitivity, high resolution, high light transmittance, few defects during development, and can resist resist film thinning when used as a resist composition in DUV excimer laser lithography and the like. Resist polymer, resist polymer having resistance, higher refractive index than immersion liquid, and excellent copolymerizability with other monomers when used in immersion resist composition It is an object of the present invention to provide a resist composition containing a substrate and a method for producing a substrate on which a pattern using the resist composition is formed.

The present invention is a resist polymer that contains a structural unit having a naphthalene skeleton represented by the following formula (1-3) (excluding the structures of the following formulas (A) to ( D )) and decomposes by the action of an acid. In particular, the present invention relates to a resist composition containing the resist material, and a method for manufacturing a substrate on which a pattern using the resist composition is formed.

（式（Ａ）〜（Ｄ）中、Ｒは水素原子又は酸不安定基を表す。）

(In the formula (1-3), R ¹⁰ represents a hydrogen atom or a methyl group, G is -C (= O) -O -, - O-, was or -O-C (= O) - either G3 is 0 or 1. Y represents —C (═O) —OH, —OH, —C (═O) —OR ¹³ , or —OR ¹³ , and R ¹³ represents the number of carbon atoms. 1 to 20 represents a straight-chain, branched or cyclic hydrocarbon group, and this hydrocarbon group may have a hetero atom, and L ¹ ′ is a straight-chain or branched chain having 1 to 20 carbon atoms . Or represents a cyclic divalent hydrocarbon group, and this divalent hydrocarbon group may have a hetero atom.)

(In formulas (A) to (D), R represents a hydrogen atom or an acid labile group.)

  The resist composition containing the resist polymer of the present invention has high sensitivity, high resolution, high light transmittance to excimer laser light, few defects during development, and dry etching that can withstand thinning of the resist film High tolerance.

In addition, when the resist polymer of the present invention is used as a resist composition for immersion, the refractive index is higher than that of the immersion liquid, so that excimer laser light is not totally reflected, and a resist pattern can be formed with high resolution. Can be formed. 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.
Furthermore, a substrate on which a highly accurate fine pattern is formed can be manufactured by the manufacturing method of the present invention.

The resist polymer of the present invention will be described.
The resist polymer of the present invention contains a structural unit (A) having a naphthalene skeleton represented by the following formula (1-1).

H1 in the formula (1-1) is 0 or 1. From the viewpoint of resolution, h1 is preferably 0, and from the viewpoint of defect or resist sensitivity, h1 is preferably 1.
H2 in Formula (1-1) represents an integer of 1 to 4. From the viewpoint of resolution, h2 is preferably 1, and from the viewpoint of defect and resist sensitivity, h2 is preferably from 2 to 4.
G1 in Formula (1-1) is 0 or 1, and g2 is an integer of 0-20.
When h1 = 1, g2 is preferably 1 to 4 from the viewpoint of resolution.
G3 in the formula (1-1) is 0 or 1.
R ¹⁰ in the formula (1-1) represents a hydrogen atom or a methyl group.
G in the formula (1-1) represents one of —C (═O) —O—, —O—, and —O—C (═O) —. Among these, —C (═O) —O— or —O—C (═O) — is preferable from the viewpoint of polymerizability.

L ¹ in Formula (1-1) represents a single bond or a linear, branched, or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and the divalent hydrocarbon group includes a substituent and It may have a hetero atom.
Although it does not restrict | limit especially as a hetero atom, For example, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, etc. are mentioned.
Although it does not restrict | limit especially as a C1-C20 linear, branched, or cyclic | annular bivalent hydrocarbon group, For example, following formula (2-1)-(2-33) can be illustrated. Note that the present invention is not limited to these examples.

L ¹ in the formula (1-1) is a linear or branched divalent hydrocarbon group having 1 to 4 carbon atoms, — (CH ₂ CH ₂ O) _g21 − from the viewpoint of solubility in an organic solvent. , or _{- (CH 2 CH (CH 3} ) O) g22 - are preferred. Here, g21 and g22 each represent an integer of 1 to 5, and from the viewpoint of resolution, g21 and g22 are preferably 1 or 2.
In addition, L ¹ in formula (1-1) is preferably at least one selected from the following formulas (1-11) to (1-14) from the viewpoint of dry etching resistance.

In formula (1-11), R ¹¹¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and Z is an atomic group constituting a cyclic hydrocarbon in L ¹ .
In formula (1-12), R ¹¹² and R ¹¹³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and Z is an atomic group constituting a cyclic hydrocarbon in L ¹ .

In formula (1-13), R ¹¹⁴ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and Z is an atomic group constituting a cyclic hydrocarbon in L ¹ .
In formula (1-14), R ¹¹⁵ and R ¹¹⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and Z is an atomic group constituting a cyclic hydrocarbon in L ^1. .
In the formulas (1-11) to (1-14), the upper left bond is bonded to G, and the lower right bond is bonded to an oxygen atom or a naphthalene ring.

Furthermore, when G is -C (= O) of -O-, in terms of resist sensitivity, L ¹ in the formula _{(1-1), -C (CH 3) 2 -} , - C (CH 3) 2 At least one selected from —CH ₂ —, —C (CH ₃ ) (CH ₂ CH ₃ ) —, the formula (1-11), and the formula (1-12) is more preferable.
When h1 = 1, from the viewpoint of resist sensitivity, L ¹ in the formula (1-1) is —C (CH ₃ ) ₂ —, —CH ₂ —C (CH ₃ ) ₂ —, —C ( CH ₃ ) (CH ₂ CH ₃ ) —, at least one selected from the above formula (1-13) and the above formula (1-14) is more preferable.

R ¹¹ and R ^{12 in} formula (1-1) are each independently esterified with a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, or an alcohol having 1 to 6 carbon atoms. Or R ¹¹ and R ¹² together represent —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6.
In the case of h1 = 1, R ¹¹ and R ¹² in the formula (1-1) are each independently a hydrogen atom or a straight chain having 1 to 4 carbon atoms from the viewpoint of transparency and resolution with respect to excimer laser light. Or a branched alkyl group is preferable.

Y in Formula (1-1) represents —C (═O) —OH, —OH, —C (═O) —OR ¹³ , or —OR ¹³ , and R ¹³ has 1 to 20 carbon atoms. A linear, branched, or cyclic hydrocarbon group is represented, and this hydrocarbon group may have a hetero atom.
From the viewpoint of 193 nm transmittance, Y is preferably —OH or —OR ¹³ , particularly preferably —OH. R ¹³ represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms, and this hydrocarbon group may have a hetero atom.
The R ^13, is not particularly limited, for example, the following formula (3-1) to (3-27) can be mentioned. Note that the present invention is not limited to these examples.

Y in formula (1-1) is preferably —C (═O) —OH or —OH from the viewpoints of defect, line edge roughness, and resist sensitivity, and the storage stability of the resist composition. Are preferably acid leaving groups represented by the following formulas (1-21) to (1-24).
In the present invention, the “acid leaving group” means a group that decomposes or leaves by the action of an acid.

(In Formula (1-21), R ¹²¹ , R ¹²² , and R ¹²³ are each independently (i) a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or 1 to 4 or a straight chain or branched alkyl group, and at least one of R ¹²¹ , R ¹²² and R ¹²³ is the alicyclic hydrocarbon group or a derivative thereof; or (ii) R ¹²¹ , R ¹²² , Any two of R ¹²³ 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 each is bonded, and R ¹²¹ , R ¹²² , And the remaining one of R ¹²³ that did not participate in the bond 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. .

In formula (1-22), ^R133 represents (i) 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 ¹³¹ and R ¹³² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or (ii) two of R ¹³¹ and R ¹³³ or R ¹³² and R ¹³³ are bonded to each other. Then, together with the carbon atom to which each is bonded, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof is formed, and the remaining ones of R ¹³¹ and R ¹³² that are not involved in the bond One represents a hydrogen atom.

In formula (1-23), R ¹⁴¹ , R ¹⁴² and R ¹⁴³ are each independently (i) a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or having 1 to 4 carbon atoms. Represents a linear or branched alkyl group, and at least one of R ¹⁴¹ , R ¹⁴² , and R ¹⁴³ is the alicyclic hydrocarbon group or a derivative thereof; or (ii) R ¹⁴¹ , R ¹⁴² , R ¹⁴³ Any two of them 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 each is bonded, and R ¹⁴¹ , R ¹⁴² , R ^The remaining one of ¹⁴³ not involved in the bond 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.

In the formula (1-24), R ¹⁵³ represents (i) 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 ¹⁵¹ and R ¹⁵² each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or (ii) R ¹⁵¹ and R ¹⁵³ or R ¹⁵² and R ¹⁵³ are bonded to each other. Then, together with the carbon atom to which each is bonded, a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof is formed, and the remaining 1 of R ¹⁵¹ and R ¹⁵² not participating in the bond One represents a hydrogen atom. )

G4 in the formula (1-1) is preferably 1 in terms of transparency to excimer laser light and resist sensitivity when Y is any one of the formulas (1-21) to (1-23), When Y is the formula (1-24), 0 is preferable from the viewpoint of transparency to excimer laser light and resist sensitivity.
L ² in the formula (1-1) represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and the divalent hydrocarbon group includes a substituent and It may have a hetero atom.
In formula (1-1), when g4 = 1, L ² is a linear or branched divalent hydrocarbon group having 1 to 4 carbon atoms, — (OCH ₂₎ , from the viewpoint of solubility in an organic solvent. CH _{2) g31} -, or _{- (OCH 2 CH (CH 3} )) g32 - it is preferred. Here, g31 and g32 each represent an integer of 1 to 5, and from the viewpoint of resolution, g31 and g32 are preferably 1 or 2.

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 from the viewpoint of reducing defects in the resist composition and improving pattern rectangularity.
h11 is preferably 0 from the viewpoint of resolution.

The structural unit (A) having a naphthalene skeleton represented by the formula (1-1) may be one type or two or more types.
The structural unit (A) having a naphthalene skeleton represented by the formula (1-1) is preferably the following formula (7-1) from the viewpoint of transparency to 193 nm excimer laser light.

In formula (7-1), R ¹⁰ , R ¹¹ , R ¹² , G, L ¹ , L ² , X ¹ , Y, h1, h2, h11, g1, g2, g3, and g4 are each represented by formula (1- It is synonymous with 1).
The structural unit (A) having a naphthalene skeleton represented by the formula (7-1) can be used alone or in combination of two or more as necessary.

  The content of the structural unit (A) having a naphthalene skeleton represented by the formula (1-1) is not particularly limited, but is 3 mol in the structural unit of the resist polymer from the viewpoint of dry etching resistance and refractive index. % Or more is preferable, and 5 mol% or more is more preferable. Further, in terms of sensitivity and resolution, 50 mol% or less is preferable, 40 mol% or less is more preferable, and 30 mol% or less is more preferable.

  The polymer containing the structural unit (A) having a naphthalene skeleton represented by the formula (1-1) gives a structural unit (A) having a naphthalene skeleton, and is a single unit represented by the following formula (1-6). It can be produced by polymerizing a monomer containing the monomer (a).

（式（１−６）中、Ｒ¹⁰、Ｒ¹¹、Ｒ¹²、Ｇ、Ｌ¹、Ｌ²、Ｘ¹、Ｙ、ｇ１、ｇ２、ｇ３、ｇ４、ｈ１、ｈ２、およびｈ１１は、式（１−１）と同義である。）

(In the formula (1-6), R ¹⁰ , R ¹¹ , R ¹² , G, L ¹ , L ² , X ¹ , Y, g ¹ , g 2, g 3, g 4, h 1, h 2, and h 11 are represented by the formula (1 -1).

  The monomer (a) represented by the formula (1-6) is not particularly limited, and examples thereof include monomers represented by the following formulas (8-1) to (8-78). In formulas (8-1) to (8-78), R represents a hydrogen atom or a methyl group.

Among these, from the viewpoint of defects and line edge roughness, the above formulas (8-1) to (8-30), the above formulas (8-38) to (8-52), and the above formulas (8-60) to (8- 70), and geometrical isomers and optical isomers thereof are more preferable. Among these, from the viewpoint of resist sensitivity, the above formulas (8-11) to (8-12), and the above formulas are preferred. (8-15) to (8-20), formulas (8-23) to (8-28), formulas (8-46) to (8-47), formulas (8-49) to (8) -52), monomers represented by the above formula (8-69), and geometrical isomers and optical isomers thereof are more preferable.
From the viewpoint of the storage stability of the resist composition, the above formulas (8-31) to (8-37), the above formulas (8-53) to (8-59), and the above formulas (8-71) to ( The monomers represented by 8-78) and geometrical isomers and optical isomers thereof are more preferable.

  Among the structural units having a naphthalene skeleton represented by the formula (1-1), a naphthalene skeleton represented by the following formula (1-2) from the viewpoint of transparency to 193 nm excimer laser light, defects, or line edge roughness A structural unit having a naphthalene skeleton represented by the following formula (1-3) is more preferred, a structural unit having a naphthalene skeleton represented by the following formula (1-4) is more preferred, A structural unit having a naphthalene skeleton represented by the formula (1-5) is particularly preferable.

In formulas (1-2) to (1-5), R ¹⁰ , G, L ¹ , Y, g3, and h2 have the same meaning as in formula (1-1).
In formula (1-3), L ¹ ′ represents a linear, branched, or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and the divalent hydrocarbon group has a hetero atom. Also good.
In formulas (1-4) and (1-5), L ¹ ″ represents a linear hydrocarbon group having 1 to 4 carbon atoms.

  The resist polymer of the present invention can increase the refractive index of the resist composition by containing the structural unit (A) having a naphthalene skeleton represented by the formula (1-1). However, when pure water is used, the effect of reducing defects in the resist composition is obtained.

  In the resist polymer containing the structural unit (A), when the structural unit (A) has an acid leaving group (when Y is an acid leaving group), the acid leaving group is By desorption, 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 (when Y is —C (═O) —OH or —OH), the structural unit (A) itself is acidic. For this reason, the resist polymer containing the structural unit (A) becomes soluble in alkali and enables formation of a resist pattern.

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

  The resist polymer of the present invention contains the structural unit (A) having a naphthalene skeleton represented by the formula (1-1), and if necessary, the structural unit (B) having a lactone skeleton. Other structural units such as a structural unit (C) having an acid leaving group and a structural unit (D) having a hydrophilic group may be contained.

The structural unit (B) having a lactone skeleton will be described.
The structural unit (B) having a lactone skeleton is preferably used as a structural component of the resist polymer because it exerts the effect of developing the adhesion of the resist composition to the substrate.
The content of the structural unit (B) is not particularly limited, but is preferably 30 mol% or more, more preferably 35 mol% or more, in the structural unit of the resist polymer, from the viewpoint of adhesion to the substrate. Further, in terms of resist sensitivity and resolution, it is preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less.

Further, when the structural unit (B) has a group that is decomposed or eliminated by the action of an acid, it tends to have better sensitivity. In this case, the structural unit (B) corresponds to a structural unit (C) described later, but 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) corresponds to a structural unit (D) to be described later, but in the present invention, such a structural unit is regarded as the structural unit (B).

The structural unit (B) having a lactone skeleton is not particularly limited, but is at least one selected from the group consisting of the following formulas (4-1) to (4-6) from the viewpoint of sensitivity or dry etching resistance. It is preferable.

In formula (4-1), R ⁴¹ represents a hydrogen atom or a methyl group, and R ⁴⁰¹ and R ⁴⁰² each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, or a carboxy group. Or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or R ⁴⁰¹ and R ⁴⁰² together represent —O—, —S—, —NH—, or a chain length of 1 to 6 Methylene chain [— (CH ₂ ) _j — (j represents an integer of 1 to 6)].

i represents 0 or 1, X ⁵ represents 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, an alkoxy group having 1 to 6 carbon atoms, carbon A carboxy group esterified with an alcohol having a number of 1 to 6 or an amino group is represented. 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 esterified carboxy group, cyano group, and amino group.
n5 represents an integer of 0 to 4, and m represents 1 or 2. In addition, when n5 is 2 or more, it includes having a plurality of different groups as X ⁵ .

Wherein (4-2), R ⁴² represents a hydrogen atom or a methyl group, each R ^201, R ²⁰² is independently hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy group, carboxy group Or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms.
Each of A ¹ and A ² independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms Or A ¹ and A ² are taken together to form —O—, —S—, —NH—, or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) _k — (k is an integer of 1 to 6 Represents)].

X ⁶ is an ester of 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, an alkoxy group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms. Represents a carboxy group, 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, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or a cyano group. And at least one group selected from the group consisting of amino groups.
n6 represents an integer of 0 to 4. In addition, when n6 is 2 or more, it includes having a plurality of different groups as X ⁶ .

In formula (4-3), R ⁴³ represents a hydrogen atom or a methyl group, and R ²⁰³ and R ²⁰⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, or a carboxy group. Or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms.
Each of A ³ and A ⁴ independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms Or A ³ and A ⁴ are taken together to form —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) ₁ — (l is an integer of 1 to 6 Represents)].

X ⁷ is an ester of 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, an alkoxy group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms. Represents a carboxy group, 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, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or a cyano group. And at least one group selected from the group consisting of amino groups.
n7 represents an integer of 0 to 4. In addition, when n7 is 2 or more, it includes having a plurality of different groups as X ⁷ .

Wherein (4-4), R ⁴⁴ represents a hydrogen atom or a methyl ^{group, R 205, R 206, R} 207 each independently represent a hydrogen atom or a methyl group. 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—.

X ⁸ is an ester of 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, an alkoxy group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms. Represents a carboxy group, 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, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or a cyano group. And at least one group selected from the group consisting of amino groups.
n8 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ⁸ in the case of n8 is 2 or more.

In formula (4-5), R ⁹¹ , R ⁹² , R ⁹³ and R ⁹⁴ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, or 1 carbon atom. Represents a carboxy group esterified with ˜6 alcohols, or R ⁹¹ and R ⁹² together represent —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)], and m1 represents 1 or 2. )

Wherein (4-6), R45 represents a hydrogen atom or a methyl group, each R ^208, R ²⁰⁹ is independently hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, hydroxy group, carboxy group, Alternatively, it represents a carboxy group esterified with an alcohol having 1 to 6 carbon atoms.
R ²¹⁰ and R ²¹¹ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. Each of A ⁵ and A ⁶ independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group, or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms; Or A ⁵ and A ⁶ are combined together to form —O—, —S—, —NH—, or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) _k1 — (k1 is an integer of 1 to 6) Represents)]. Y ²¹ and Y ²² each independently represent —CH ₂ — or —C (═O) —, and at least one of them represents —C (═O) —.

X ⁹ is an ester of 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, an alkoxy group having 1 to 6 carbon atoms, or an alcohol having 1 to 6 carbon atoms. Represents a carboxy group, 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, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or a cyano group. And at least one group selected from the group consisting of amino groups. n9 represents an integer of 0 to 4. In addition, when n9 is 2 or more, it includes having a plurality of different groups as X ⁹ .

N5 in the formula (4-1) is preferably 0 from the viewpoint of high dry etching resistance.
M in the formula (4-1) is preferably 1 in terms of sensitivity and resolution.

In terms of high dry etching resistance, A ¹ and A ^{2 in} formula (4-2) are preferably combined together to form —CH ₂ — and —CH ₂ CH ₂ — and dissolved in an organic solvent. From the standpoint of high properties, it is preferable to form —O— together.
R ²⁰¹ and R ^{202 in} formula (4-2) are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent.
N6 in the formula (4-2) is preferably 0 from the viewpoint of high dry etching resistance.

As A ³ and A ⁴ in the formula (4-3), from the viewpoint of high dry etching resistance, it is preferable that they together form —CH ₂ — or —CH ₂ CH ₂ —. From the viewpoint of high solubility, it is preferable that they are taken together as -O-.
R ²⁰³ and R ^{204 in} formula (4-3) are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent.
N7 in Formula (4-3) is preferably 0 from the viewpoint of high dry etching resistance.

R ²⁰⁵ , R ²⁰⁶ , and R ^{207 in} formula (4-4) are preferably hydrogen atoms from the viewpoint of high solubility in an organic solvent.
Y ¹¹ , Y ¹² and Y ¹³ in the formula (4-4) are one of —C (═O) —O— and the other two are —CH—from the viewpoint of high adhesion to the substrate surface and the like. _2- is preferred.
N8 in Formula (4-4) is preferably 0 from the viewpoint of high dry etching resistance.

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.

As A ⁵ and A ⁶ in the formula (4-6), from the viewpoint of high dry etching resistance, it is preferable that they together form —CH ₂ — or —CH ₂ CH ₂ —. From the viewpoint of high solubility, it is preferable that they are taken together as -O-.
R ²⁰⁸ and R ^{209 in} formula (4-6) are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent.

R ²¹⁰ and R ^{211 in} formula (4-6) are each independently preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent.
In formula (4-6), Y ²¹ and Y ²² are each one of —C (═O) — and the other one of —CH ₂ — from the viewpoint of high adhesion to the substrate surface and the like. Is preferred.
N9 in Formula (4-6) is preferably 0 from the viewpoint of high dry etching resistance.

The structural unit (B) having a lactone skeleton can be used alone or in combination of two or more as necessary.
The polymer having the structural unit (B) having a lactone skeleton can be produced by polymerizing a monomer containing the monomer (b) that gives the structural unit (B) having a lactone skeleton.
The monomer (b) is not particularly limited, and examples thereof include monomers represented by the following formulas (10-1) to (10-29). In formulas (10-1) to (10-29), 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 (10-29), and geometrical isomers and optical isomers thereof are more preferable. From the viewpoint of solubility in a resist solvent, the above formula (10-8), Monomers represented by (10-13), (10-16) to (10-23), and (10-28), and geometric isomers and optical isomers thereof are more preferable.

The structural unit (C) having an acid leaving group will be described.
Here, the “acid-leaving group” refers to a group that decomposes or leaves by the action of an acid.
The structural unit (C) having an acid-eliminable group is a component that is soluble in an alkali by an acid, and has an effect of enabling the formation of a resist pattern. .
The content of the structural unit (C) is not particularly limited, but is preferably 20 mol% or more, more preferably 25 mol% or more in the structural unit of the resist polymer from the viewpoint of sensitivity and resolution. Moreover, 60 mol% or less is preferable from the point of the adhesiveness to a substrate surface etc., 55 mol% or less is more preferable, and 50 mol% or less is more preferable.

When the structural unit (C) has a lactone skeleton, the substrate adhesion 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).
In addition, when the structural unit (C) has a hydrophilic group, it tends to have more excellent sensitivity. In this case, the structural unit (C) corresponds to a structural unit (D) to be described later, but in the present invention, such a structural unit is regarded as the structural unit (C).

  The structural unit (C) having an acid-eliminable group is not particularly limited, but has the following formulas (3-1-1) and (3-2-1) because the dry etching resistance required for the resist is high. ), (3-3-1), (3-4-1), (3-5-1), (3-6-1), (3-7-1) and (3-8-1) It is preferably at least one selected from the group consisting of

In formula (3-1-1), R ³¹ represents a hydrogen atom or a methyl group, R ¹ represents an alkyl group having 1 to 3 carbon atoms, and X ¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms. N1 represents an integer of 0 to 4. In addition, when n1 is 2 or more, it includes having a plurality of different groups as X ¹ .
In formula (3-2-1), R ³² represents a hydrogen atom or a methyl group, R ² and R ³ each independently represents an alkyl group having 1 to 3 carbon atoms, and X ² represents 1 to 6 carbon atoms. N2 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ² in the case of n2 is 2 or more.

In formula (3-3-1), R ³³ represents a hydrogen atom or a methyl group, R ⁴ represents an alkyl group having 1 to 3 carbon atoms, and R ³³¹ , R ³³² , R ³³³ , and R ³³⁴ are each independently A hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and V ¹ and V ² 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)], X ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms, n3 represents an integer of 0 to 4, q Represents 0 or 1. In addition, when n3 is 2 or more, it includes having a plurality of different groups as X ³ .

In formula (3-4-1), R ³⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkyl group having 1 to 3 carbon atoms, and X ⁴ represents a linear or branched alkyl group having 1 to 6 carbon atoms. Represents a group, n4 represents an integer of 0 to 4, and r represents an integer of 0 to 2. In addition, when n4 is 2 or more, it includes having a plurality of different groups as X ⁴ .

In formula (3-5-1), R ³⁵ represents a hydrogen atom or a methyl group, and R ³⁵¹ , R ³⁵² , R ³⁵³ , and R ³⁵⁴ are each independently a hydrogen atom, a linear or branched alkyl having 1 to 6 carbon atoms. V ³ and V ⁴ each independently represents —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) _u11 — (u11 represents an integer of 1 to 6; represents represents)], X ⁵¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, n51 represents an integer of 0 to 4, q3 is 0 or 1.

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 the alicyclic hydrocarbon group or a derivative thereof, or any two of R ³⁵⁵ , R ³⁵⁶ , and R ³⁵⁷ are bonded to each other, and each is bonded Together with the carbon atom forming a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, the remaining one of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ not participating in the bond is 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 is represented. In addition, when n51 is 2 or more, it includes having a plurality of different groups as X ⁵¹ .

In formula (3-6-1), R ³⁶ represents a hydrogen atom or a methyl group, and R ³⁶¹ , R ³⁶² , R ³⁶³ , and R ³⁶⁴ are each independently a hydrogen atom, a linear or branched alkyl having 1 to 6 carbon atoms. V ⁵ and V ⁶ each independently represent —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) _u12 — (u12 represents an integer of 1 to 6). represents represents)], X ⁶¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, n61 represents an integer of 0 to 4, q4 is 0 or 1.

R ³⁶⁷ represents 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, R ³⁶⁶ are each independently hydrogen Represents an atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or R ³⁶⁵ and R ³⁶⁷ or R ³⁶⁶ and R ³⁶⁷ are bonded to each other, together with the carbon atom to which each is bonded , A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and the remaining one of R ³⁶⁵ and R ³⁶⁶ not participating in the bond represents a hydrogen atom. Incidentally, also includes having a plurality of different groups as X ⁶¹ in the case of n61 is 2 or more.

In formula (3-7-1), R ³⁷ represents a hydrogen atom or a methyl group. 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, and R ³⁷¹ and R ³⁷² are each independently hydrogen. Represents an atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or R ³⁷¹ and R ³⁷³ or R ³⁷² and R ³⁷³ are bonded to each other, together with the carbon atom to which each is bonded , A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and the remaining one of R ³⁷¹ and R ³⁷² not participating in the bond represents a hydrogen atom.
In formula (3-8-1), R ³⁸ represents a hydrogen atom or a methyl group. R ³⁸¹ , R ³⁸² and R ³⁸³ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms. )

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

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

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.
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 high dry etching resistance.
R ³³¹ , R ³³² , R ³³³ , and R ³³⁴ in formula (3-3-1) are each independently a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent. It is preferable that
N3 in Formula (3-3-1) is preferably 0 from the viewpoint of high dry etching resistance.
Q in Formula (3-3-1) is preferably 1 from the viewpoint of high dry etching resistance, and preferably 0 from the viewpoint of good solubility 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 sensitivity and resolution.
N4 in the formula (3-4-1) is preferably 0 from the viewpoint of high dry etching resistance.
R in the formula (3-4-1) is preferably 1 from the viewpoint of high dry etching resistance, and preferably 0 from the viewpoint of good solubility 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 viewpoint of high dry etching resistance.
R ³⁵¹ , R ³⁵² , R ³⁵³ , and R ³⁵⁴ in formula (3-5-1) are each independently a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent. It is preferable that
N51 in Formula (3-5-1) is preferably 0 from the viewpoint of high dry etching resistance.

Q3 in the formula (3-5-1) is preferably 1 from the viewpoint of high dry etching resistance, and preferably 0 from the viewpoint of good solubility in an organic solvent.
-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.

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

-C (R ³⁶⁵ ) (R ³⁶⁶ ) -O-R ³⁶⁷ in the formula (3-6-1) is the following formula (J-1) to (J-24) in that it is excellent in line edge roughness. In terms of high dry etching resistance, structures represented by the following formulas (J-25) to (J-52) are preferable.

-C (R ³⁷¹ ) (R ³⁷² ) -O-R ³⁷³ in the formula (3-7-1) is the above formula (J-1) to (J-24) in that the line edge roughness is excellent. In terms of high dry etching resistance, the structures represented by the above formulas (J-25) to (J-52) are preferable.
The structural unit (C) having an acid leaving group can be used alone or in combination of two or more as necessary.

The polymer having the structural unit (C) having an acid leaving group is produced by polymerizing a monomer containing the monomer (c) that gives the structural unit (C) having an acid leaving group. be able to.
The monomer (c) is not particularly limited, and examples thereof include monomers represented by the following formulas (9-1) to (9-224). In formulas (9-1) to (9-224), R and R ′ each independently represents a hydrogen atom or a methyl group.

  Among these, from the points of sensitivity and resolution, the above formulas (9-1) to (9-3), the above formula (9-5), the above formula (9-16), the above formula (9-19), the above formula ( 9-20), the above formula (9-22), the above formula (9-23), the above formulas (9-25) to (9-28), the above formula (9-30), and the above formula (9-31). The monomers represented by the above formula (9-33), the above formula (9-34) and the above formulas (9-102) to (9-129), and their geometrical isomers and optical isomers. Preferably, the formula (9-1), the formula (9-2), the formula (9-16), the formula (9-20), the formula (9-23), the formula (9-28), Formula (9-31), Formula (9-34), Formula (9-109), Formula (9-111), Formula (9-114) to (9-117), Formula (9) -125 A monomer represented by the formula (9-128) and the formula (9-129) is particularly preferred.

  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, monomers represented by the above formulas (9-76) to (9-88), monomers represented by the above formulas (9-130) to (9-135), the above formula (9 -147) to (9-157), monomers represented by the above formulas (9-171) to (9-183), and their geometrical isomers and optical isomers. preferable.

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). A monomer, a monomer represented by the above formulas (9-89) to (9-101), a monomer represented by the above formulas (9-136) to (9-146), the above formula (9 -158) to (9-170), monomers represented by the above formulas (9-184) to (9-196), and geometric isomers and optical isomers thereof. preferable.
In addition, from the viewpoint of good pattern rectangularity, monomers represented by the above formulas (9-197) to (9-224), and geometric isomers and optical isomers thereof are more preferable.

The structural unit (D) having a hydrophilic group will be described.
Here, the “hydrophilic group” is at least one of —C (CF ₃ ) ₂ —OH, hydroxy group, cyano group, methoxy group, carboxy group, and amino group.
The structural unit (D) having a hydrophilic group is preferably used as a structural unit of a resist polymer because it has an effect of reducing defects in the resist composition and improving pattern rectangularity.
The content of the structural unit (D) is preferably 5 to 30 mol%, more preferably 10 to 25 mol%, in the structural unit of the resist polymer, from the viewpoint of pattern rectangularity.

When the structural unit (D) has a group that decomposes or leaves by the action of an acid, it tends to have better sensitivity. 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 the structural unit (C).
Moreover, when the structural unit (D) has a lactone skeleton, it tends to have more excellent sensitivity. In this case, the structural unit (D) corresponds to the structural unit (B), but in the present invention, such a structural unit is regarded as the structural unit (B).

The structural unit (D) having a hydrophilic group is not particularly limited, but is selected from the group consisting of the following formulas (5-1) to (5-7) from the viewpoint of high dry etching resistance required for a resist. What is at least 1 type is preferable.

In formula (5-1), R ⁵¹ represents a hydrogen atom or a methyl group, R ⁵⁰¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X ⁵¹ represents a straight or branched chain having 1 to 6 carbon atoms. Esterification with alkyl group, —C (CF ₃ ) ₂ —OH, hydroxy group, cyano group, carboxy group, C 1-6 acyl group, C 1-6 alkoxy group, C 1-6 alcohol Represents a carboxy group or an amino group.
The linear or branched alkyl group having 1 to 6 carbon atoms is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group esterified with 6 alcohols and an amino group. n51 represents an integer of 1 to 4. In addition, when n51 is 2 or more, it includes having a plurality of different groups as X ₅₁ .

In the formula (5-2), R ⁵² represents a hydrogen atom or a methyl group, X ⁵² represents a linear or branched alkyl group having 1 to 6 carbon atoms, —C (CF ₃ ) ₂ —OH, a hydroxy group, cyano A 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 is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group esterified with 6 alcohols and an amino group. n52 represents an integer of 1 to 4. Incidentally, also includes having a plurality of different groups as X ⁵² in the case of n52 is 2 or more.

In formula (5-3), R ⁵³ represents a hydrogen atom or a methyl group, R ⁵⁰² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ^{531 to} R ⁵³⁴ independently represent a hydrogen atom, carbon Represents a linear or branched alkyl group of 1 to 6, W ¹ and W ² 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)].
X ⁵³ is a linear or branched alkyl group having 1 to 6 carbon atoms, —C (CF ₃ ) ₂ —OH, hydroxy group, cyano group, carboxy group, acyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms. An alkoxy group, a carboxy group esterified with an alcohol having 1 to 6 carbon atoms or an amino group, and n53 represents an integer of 1 to 4. The linear or branched alkyl group having 1 to 6 carbon atoms is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group esterified with 6 alcohols and an amino group. q1 represents 0 or 1. Incidentally, also includes having a plurality of different groups as X ⁵³ in the case of n53 is 2 or more.

In the formula (5-4), R ⁵⁴ represents a hydrogen atom or a methyl group, R ⁵⁰³ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and X ⁵⁴ is a linear or branched group having 1 to 6 carbon atoms. Esterification with alkyl group, —C (CF ₃ ) ₂ —OH, hydroxy group, cyano group, carboxy group, C 1-6 acyl group, C 1-6 alkoxy group, C 1-6 alcohol Represents a carboxy group or an amino group.
The linear or branched alkyl group having 1 to 6 carbon atoms is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group esterified with 6 alcohols and an amino group. n54 represents an integer of 1 to 4, and r1 represents an integer of 0 to 2. Incidentally, also includes having a plurality of different groups as X ⁵⁴ in the case of n54 is 2 or more.

Wherein (5-5), R ⁵⁵ represents a hydrogen atom or a methyl group, R ^504, R ⁵⁰⁵ each independently represents an alkyl group having 1 to 3 carbon atoms, X ⁵⁵ represents a linear 1 to 6 carbon atoms chain or branched alkyl _{group, -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, alcohols having 1 to 6 carbon atoms Represents a carboxy group esterified with or an amino group. As the linear or branched alkyl group substituent 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, or an alkyl group having 1 to 6 carbon atoms. It may have at least one group selected from the group consisting of a carboxyl group esterified with an alcohol and an amino group. n55 represents an integer of 1 to 4. Incidentally, also includes having a plurality of different groups as X ⁵⁵ in the case of n55 is 2 or more.

In Formula (5-6), R ⁵⁶ represents a hydrogen atom or a methyl group, R ⁵⁰⁶ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ^{535 to} R ⁵³⁶ independently represent a hydrogen atom or a carbon number. 1 to 6 linear or branched alkyl groups, W ³ represents —O—, —S—, —NH—, or a methylene chain having a chain length of 1 to 6 [— (CH ₂ ) _u3 — (u3 represents 1 to 6 Represents an integer of
X ⁵⁶ represents a linear or branched alkyl group having 1 to 6 carbon _{atoms, -C (CF 3) 2 -OH} , hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, 1 to 6 carbon atoms An alkoxy group, 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 is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group and an amino group esterified with 6 alcohols. n56 represents an integer of 1 to 4, and q2 represents 0 or 1. Incidentally, also includes having a plurality of different groups as X ⁵⁶ in the case of n56 is 2 or more.

In the formula (5-7), R ⁵⁷ represents a hydrogen atom or a methyl group, R ⁵⁷¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms, or Represents a linear or branched alkyl group having 1 to 6 carbon atoms having a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms, R ⁵⁷² represents a linear or branched alkyl group having 1 to 6 carbon atoms, Alternatively, R ⁵⁷¹ and R ⁵⁷² may be combined to form a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms with the carbon atom to which each is bonded.
Here, the alkyl group 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. The pre-bridged cyclic hydrocarbon group 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, or an acyl group having 2 to 6 carbon atoms. Or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms.

X ⁵⁷ is a linear or branched alkyl group having 1 to 6 carbon atoms, —C (CF ₃ ) ₂ —OH, hydroxy group, cyano group, carboxy group, acyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms. An alkoxy group, 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 is substituted with —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, It may have at least one group selected from the group consisting of a carboxy group esterified with 6 alcohols and an amino group.

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

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

R ⁵⁰² in formula (5-3) is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution, and is preferably a hydrogen atom from the viewpoint of good solubility in an organic solvent. preferable.
W ¹ and W ^{2 in} Formula (5-3) 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) are each independently a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group because of their high solubility in organic solvents. Preferably there is.

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

R ⁵⁰³ in formula (5-4) is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution, and is preferably a hydrogen atom from the viewpoint of good solubility in an organic solvent. preferable.
N54 in Formula (5-4) is preferably 1 from the viewpoint of high dry etching resistance.
X ⁵⁴ in formula (5-4) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group from the viewpoint of good pattern shape.
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 formula (5-5), R ⁵⁰⁴ and R ⁵⁰⁵ are preferably each independently a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution.
N55 in Formula (5-5) is preferably 1 from the viewpoint of high dry etching resistance.
X ⁵⁵ in formula (5-5) is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group from the viewpoint of good pattern shape.

R ⁵⁰⁶ in formula (5-6) is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution, and is preferably a hydrogen atom from the viewpoint of good solubility in an organic solvent. preferable.
W ³ in formula (5-6) is preferably —CH ₂ — or —CH ₂ CH ₂ — from the viewpoint of high dry etching resistance.
R ⁵³⁵ and R 5 ^{36 in} formula (5-6) are preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group from the viewpoint of high solubility in an organic solvent.

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

R ⁵⁷¹ and R ^{572 in} formula (5-7) have a high dry etching resistance, so that R ⁵⁷¹ and R ⁵⁷² together have 4 to 16 carbon atoms together with the carbon atoms to which they are bonded. A structure forming a bridged cyclic hydrocarbon group is preferred. In addition, from the viewpoint of excellent heat resistance and stability, the ring contained in the bridged cyclic hydrocarbon group formed together with the carbon atom to which R ⁵⁷¹ and R ⁵⁷² are bonded together is a camphor ring. , An adamantane ring, a norbornane ring, a pinane ring, a bicyclo [2.2.2] octane ring, a tetracyclododecane ring, a tricyclodecane ring, or a decahydronaphthalene ring.

X ⁵⁷ 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. It is preferably a —O—CH ₃ group or a — (CH ₂ ) ₂ —O—CH ₃ group.
In the formulas (5-1) to (5-7), the position substituted with X ⁵¹ , X ⁵² , X ⁵³ , X ⁵⁴ , X ⁵⁵ , X ⁵⁶ and X ⁵⁷ is any position in the cyclic structure. May be.
The structural unit (D) having a hydrophilic group can be used alone or in combination of two or more as necessary.

The polymer having the structural unit (D) having a hydrophilic group can be produced by polymerizing a monomer containing the monomer (d) that gives the structural unit (D) having a hydrophilic group.
The monomer (d) is not particularly limited, and examples thereof include monomers represented by the following formulas (13-1) to (13-79). In formulas (13-1) to (13-79), R represents a hydrogen atom or a methyl group.

  Among these, from the viewpoint of good solubility in a resist solvent, the above formulas (13-1) to (13-9), the above formulas (13-13) to (13-16), and the above formulas (13-21) to (13-24), the above formulas (13-30) to (13-34), the above formulas (13-37) to (13-43), the above formulas (13-56) to (13-59), the above formulas (13-62) to (13-63), the above formulas (13-66) to (13-69), the above formula (13-72), and the above formulas (13-76) to (13-79). Monomers, and geometric isomers thereof, and optical isomers thereof are more preferable.

  Further, from the viewpoint of high dry etching resistance, the above formulas (13-25) to (13-30), the above formulas (13-44) to (13-55), and the above formulas (13-60) to (13-61). ), Monomers represented by the above formulas (13-64) to (13-65), the above formula (13-71), the above formulas (13-73) to (13-75), and geometrical isomerism thereof. And their optical isomers are more preferred.

The resist polymer of the present invention may contain a constituent unit (E) other than these constituent units as necessary in addition to the constituent units (B) to (D).
As such a structural unit (E), for example, a structural unit (E1) having an alicyclic skeleton (nonpolar alicyclic skeleton) having no acid-eliminable group and hydrophilic group can be contained. . 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 as necessary.

The structural unit (E1) tends to exhibit an effect of expressing the dry etching resistance of the resist composition.
The structural unit (E1) is not particularly limited, but structural units represented by the following formulas (11-1) to (11-4) are preferable from the viewpoint of high dry etching resistance required for the resist.

In formula (11-1), R ³⁰¹ represents a hydrogen atom or a methyl group, X ³⁰¹ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and n301 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ³⁰¹ in the case of n301 is 2 or more.
Wherein (11-2), R ³⁰² represents a hydrogen atom or a methyl group, X ³⁰² represents a linear or branched alkyl group having 1 to 6 carbon atoms, n302 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ³⁰² in the case of n302 is 2 or more.

In formula (11-3), R ³⁰³ represents a hydrogen atom or a methyl group, X ³⁰³ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and n303 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ³⁰³ in the case of n303 is 2 or more. Moreover, p represents the integer of 0-2.
In formula (11-4), R ³⁰⁴ represents a hydrogen atom or a methyl group, X ³⁰⁴ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and n304 represents an integer of 0 to 4. Incidentally, also includes having a plurality of different groups as X ³⁰⁴ in the case of n304 is 2 or more. Moreover, p1 represents the integer of 0-2. )
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 in Formula (11-1) is preferably 0 from the viewpoint of high dry etching resistance.
N302 in Formula (11-2) is preferably 0 from the viewpoint of high dry etching resistance.
N303 in Formula (11-3) is preferably 0 from the viewpoint of high dry etching resistance.
P in Formula (11-3) is preferably 0 from the viewpoint of high solubility in an organic solvent, and is preferably 1 from the viewpoint of high dry etching resistance.
N304 in Formula (11-4) is preferably 0 from the viewpoint of high dry etching resistance.
P1 in formula (11-4) is preferably 0 from the viewpoint of high solubility in an organic solvent, and is preferably 1 from the viewpoint of high dry etching resistance.

The polymer containing the structural unit (E1) having a nonpolar alicyclic skeleton can be produced by polymerizing a monomer containing the monomer (e1) having a nonpolar alicyclic skeleton.
The monomer (e1) having a nonpolar alicyclic skeleton is not particularly limited, and examples thereof include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, and (meth) acrylic acid. Adamantyl, tricyclodecanyl (meth) acrylate, 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 Is preferred.
Specific examples 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 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 including the monomer (e2).

The monomer (e2) is not particularly limited. 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, methoxymethyl (meth) acrylate, n-propoxyethyl (meth) acrylate, iso-propoxyethyl (meth) acrylate, (meth) N-butoxyethyl acrylate, iso-butoxyethyl (meth) acrylate, tert-butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) 2-hydroxy-n-propyl acrylate, 4-hydroxy (meth) acrylate n-butyl, 2-ethoxyethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3, (meth) acrylic acid 3-tetrafluoro-n-propyl, (meth) acrylic acid 2,2,3,3,3-pentafluoro-n-propyl, methyl α- (tri) fluoromethylacrylate, α- (tri) fluoromethylacrylic Ethyl acetate, 2-ethylhexyl α- (tri) fluoromethyl acrylate, n-propyl α- (tri) fluoromethyl acrylate, iso-propyl α- (tri) fluoromethyl acrylate, α- (tri) fluoromethyl acrylic N-butyl acid, iso-butyl α- (tri) fluoromethyl acrylate, tert-butyl α- (tri) fluoromethyl acrylate, α- (tri Methoxymethyl fluoromethyl acrylate, ethoxyethyl α- (tri) fluoromethyl acrylate, n-propoxyethyl α- (tri) fluoromethyl acrylate, iso-propoxyethyl α- (tri) fluoromethyl acrylate, α- ( (Meth) having a linear or branched structure such as n-butoxyethyl tri) fluoromethyl acrylate, iso-butoxyethyl α- (tri) fluoromethyl acrylate, tert-butoxyethyl α- (tri) fluoromethyl acrylate Acrylic ester;
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;
Unsaturated carboxylic acids and carboxylic anhydrides such as (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride;
Examples thereof include ethylene, propylene, norbornene, tetrafluoroethylene, acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, vinyl chloride, vinyl fluoride, vinylidene fluoride, and vinylpyrrolidone.

The content of the structural unit (E1) and the structural unit (E2) is not particularly limited, but is preferably in the range of 20 mol% or less in the structural unit of the resist polymer.
Preferred combinations of the structural unit (B) and the structural unit (C) in the resist polymer are listed in Tables 1 to 4.

  In addition, the structural unit (B) includes at least one selected from the group consisting of the formula (10-1) and the formula (10-3), the formula (10-7), (10-8), ( 10-10), (10-12), (10-17) and one or more selected from the group consisting of the formula (10-19) may be used in combination. Furthermore, in addition to the combinations listed in Table 1, as the structural unit (D), the formula (13-1), the formula (13-26), the formula (13-27), and the formula (13-30) In addition, a combination obtained by adding one monomer selected from the group consisting of the formula (13-31) and the formula (13-68) (hereinafter referred to as “combination A”) is also preferable. Then, with respect to the combinations listed in Table 1 or combination A, as the structural unit (E1), at least one unit selected from the group consisting of the formula (14-1) and the formula (14-3) is used. A combination to which a monomer is added is also preferable.

The weight average molecular weight of the resist polymer of the present invention is not particularly limited, but is preferably 2,000 or more, more preferably 3,000 or more, from the viewpoint of dry etching resistance and resist pattern shape, It is particularly preferably 4,000 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 20,000 or less is more preferable.
The molecular weight distribution of the resist polymer of the present invention is not particularly limited, but is preferably 2.5 or less, more preferably 2.0 or less, from the viewpoint of solubility in a resist solution and resolution. .8 or less is particularly preferable.

Next, a method for producing the resist polymer of the present invention will be described.
The method for producing the resist polymer of the present invention is not particularly limited as long as it is performed by solution polymerization. The polymerization method for solution polymerization is not particularly limited, and may be batch polymerization or dropping polymerization. Among these, a polymerization method called dropping polymerization in which a monomer is dropped into a polymerization vessel is preferable from the viewpoint that a polymer having a narrow composition distribution and / or molecular weight distribution can be easily obtained. The monomer to be dropped may be a monomer alone or a solution in which the monomer is dissolved in an organic solvent.

In the drop polymerization method, for example, an organic solvent is charged in a polymerization vessel in advance (this organic solvent is also referred to as a “charged solvent”), heated to a predetermined polymerization temperature, and then a monomer and a polymerization initiator are each independently or A solution dissolved in an organic solvent in an arbitrary combination (this organic solvent is also referred to as “dropping solvent”) is dropped into the charged solvent. The monomer may be dropped without being dissolved in the dropping solvent. In that case, the polymerization initiator may be dissolved in the monomer, or a solution in which only the polymerization initiator is dissolved in the organic solvent is organic. It may be dropped into a solvent. Further, the monomer or the polymerization initiator may be dropped into the polymerization vessel in a state where the charged solvent is not in the polymerization vessel.
The monomer and the polymerization initiator may be directly dropped from an independent storage tank to a charged solvent heated to a predetermined polymerization temperature, or dropped from an independent storage tank to a charged solvent heated to a predetermined polymerization temperature. They may be mixed immediately before the addition and dropped into the charged solvent.

Furthermore, the timing at which the monomer or the polymerization initiator is dropped into the charging solvent may be dropped after the monomer has been dropped first, or the polymerization initiator may be dropped after the monomer has been dropped. Then, the monomer may be dropped with a delay, or the monomer and the polymerization initiator may be dropped at the same timing. These dropping speeds may be constant until the dropping is completed, or may be changed in multiple stages according to the consumption speed of the monomer or polymerization initiator, or intermittently. The dripping may be stopped or started.
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.
These solvents may be used alone or in combination of two or more.

The amount of the polymerization solvent used is not particularly limited and may be determined as appropriate. Usually, it is preferable to use within the range of 30-700 mass parts with respect to 100 mass parts of monomer whole quantity used for copolymerization.
In the dropping polymerization method, when two or more 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 organic solvent is not particularly limited, but is preferably in the range of 5 to 50% by mass.
In addition, the amount of the charged solvent is not particularly limited and may be determined as appropriate. Usually, it is preferable to use within the range of 30-700 mass parts with respect to 100 mass parts of monomer whole quantity used for copolymerization.

  The resist polymer of the present invention is usually obtained by polymerizing a monomer composition containing one or more monomers having a naphthalene skeleton represented by the formula (1) in the presence of a polymerization initiator. can get. The polymerization initiator is preferably one that generates radicals efficiently by heat. Examples of such polymerization initiators include 2,2′-azobisisobutyronitrile (hereinafter also referred to as AIBN) and dimethyl-2,2′-azobisisobutyrate (hereinafter also referred to as DAIB). ) Azo compounds such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane]; 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, di (4 -Tert-butylcyclohexyl) peroxydicarbonate and other organic peroxides.

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 amount of the polymerization initiator used is not particularly limited, but is preferably 0.3 mol parts or more with respect to 100 mol parts of the total amount of monomers used for copolymerization, from the viewpoint of increasing the yield of the copolymer. More than the molar part is more preferable, and from the point of narrowing the molecular weight distribution of the copolymer, the molar amount is preferably 30 parts by mole or less with respect to 100 parts by mole of the total amount of monomers used for copolymerization.

When producing the resist polymer of the present invention, a chain transfer agent (hereinafter referred to as a chain transfer agent) may be used as long as the storage stability of the resist composition is not impaired. Examples of such chain transfer agents include 1-butanethiol, 2-butanethiol, 1-octanethiol, 1-decanethiol, 1-tetradecanethiol, cyclohexanethiol, 2-methyl-1-propanethiol, 2- Examples include hydroxyethyl mercaptan.
ArF excimer laser (wavelength: 193 nm) When producing a resist polymer used in lithography, chain transfer from the point that the light transmittance (transmittance to light with a wavelength of 193 nm) of the resulting resist polymer is not lowered as much as possible. The agent preferably has no aromatic ring.

The polymer solution produced by solution polymerization is diluted to a suitable solution viscosity with a good solvent such as 1,4-dioxane, acetone, THF, MEK, MIBK, γ-butyrolactone, PGMEA, and PGME as necessary. Then, it is dropped into a large amount of poor solvent such as methanol, water, hexane, heptane, etc. to precipitate the polymer. This process is generally called reprecipitation and is very effective for removing unreacted monomers, polymerization initiators, and the like 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.
The produced polymer solution can be used as a resist composition as it is or after diluting with an appropriate solvent. At that time, additives such as a storage stabilizer may be appropriately added.

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 alkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol monomethyl ether; esters such as ethyl acetate and ethyl lactate; n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexanol, 1 -Alcohols such as octanol; 1,4-dioxane, ethylene carbonate, γ-butyrolactone and the like. 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.
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 and 0.5 parts by mass with respect to 100 parts by mass of the resist polymer. More preferably. 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 resist polymers, 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 preferably 0.01 parts by mass or more with respect to 100 parts by mass of the resist polymer. 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 resist polymers. 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. It is preferably 01 parts by mass or more. By setting the content of these compounds within this range, the resist pattern shape can be made more rectangular. Further, the content of these compounds (organic carboxylic acid, phosphorus oxo acid, or a derivative thereof) is usually preferably 5 parts by mass or less with respect to 100 parts by mass of the resist polymer. 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 manufacturing method of the board | substrate with which the pattern of this invention was formed is demonstrated.
First, the resist composition of the present invention is applied to the surface of a substrate to be processed such as a silicon wafer on which a pattern is formed 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 through a photomask (exposure). The light used for exposure is preferably a KrF excimer laser, an ArF excimer laser, an F ₂ excimer laser, or an EUV excimer laser, and particularly preferably an ArF excimer laser. It is also preferable to expose with an electron beam.
On the other hand, immersion exposure in which exposure is performed with a high refractive index liquid such as pure water, perfluoro-2-butyltetrahydrofuran, or perfluorotrialkylamine interposed between the resist film and the final lens of the exposure apparatus. May be performed.

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.
Then, the processed substrate on which the resist pattern has been manufactured is appropriately heat-treated (post-baked) to strengthen the resist and selectively etch the portion without the resist. After the 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 addition, “part” in each example and comparative example means “part by mass” unless otherwise specified.
Moreover, the copolymerizability of the resist polymer, the resist polymer, and the resist composition were evaluated as follows.

1. Evaluation of copolymerizability of resist polymer <content of each structural unit with respect to polymerization time>
The copolymerization evaluation of the resist polymer is carried out by determining the amount of unreacted monomer present in the polymerization solution with respect to the amount of monomer charged for each polymerization time, and determining the consumption for each monomer. The ratio was compared.
The amount of monomer remaining in the polymerization solution was determined by the following method. First, in each polymerization time, 0.5 g of the polymerization solution collected from the polymerization reactor was diluted with acetonitrile, and the total volume was adjusted to 50 mL using a volumetric flask. This diluted solution was filtered through a 0.2 μm membrane filter, and the amount of each unreacted monomer was determined using a high performance liquid chromatograph HPLC-8020 (product name) manufactured by Tosoh Corporation.

  In this measurement, a separation column uses one Inertsil ODS-2 (trade name) manufactured by GL Sciences, the mobile phase is a water / acetonitrile gradient system, the flow rate is 0.8 mL / min, and the detector is UV / visible absorption by Tosoh. Measurement was performed with a photometer UV-8020 (trade name), a detection wavelength of 220 nm, a measurement temperature of 40 ° C., and an injection volume of 4 μL. The separation column Inertsil ODS-2 (trade name) used was a silica gel particle diameter of 5 μm, a column inner diameter of 4.6 mm × column length of 450 mm. The gradient conditions of the mobile phase were as follows, with the liquid A being water and the liquid B being acetonitrile. In order to quantify the amount of unreacted monomer, three types of monomer solutions having different concentrations were used as standard solutions.

Measurement time 0 to 3 minutes: A liquid / B liquid = 90 vol% / 10 vol%
Measurement time 3 to 24 minutes: Liquid A / liquid B = 90% by volume / 10% by volume → 50% by volume / 50% by volume
Measurement time: 24 to 36.5 minutes: A liquid / B liquid = 50 vol% / 50 vol% → 0 vol% / 100 vol%
Measurement time: 36.5 to 44 minutes: Liquid A / liquid B = 0 volume% / 100 volume%
About each monomer, it can be said that copolymerization is so good that the consumption ratio in each polymerization time corresponds. On the other hand, when the consumption ratio of the monomer greatly varies depending on the type of the monomer, it can be said that a polymer having a biased copolymer composition ratio is generated, and the copolymerizability is poor.

2. Evaluation of resist polymer <content of each structural unit>
If the content of each constituent unit of the resist polymer can be determined by ¹ H-NMR measurement, it can be determined by ¹ H-NMR measurement, and cannot be determined by ¹ H-NMR measurement due to proton peak overlap, etc. Was determined by ¹³ C-NMR measurement.

The measurement of ¹ H-NMR was carried out using JNM-GX270 type FT-NMR (trade name) manufactured by JEOL Ltd., and a resist polymer sample solution (deuterated chloroform solution or deuterium) of about 5% by mass. Hydrogenated dimethyl sulfoxide solution) was put in a test tube having a diameter of 5 mmφ, and the measurement was performed at an observation frequency of 270 MHz and a single pulse mode with 64 integrations. 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.
^In the case of ¹³ C-NMR measurement, using a UNITY-INOVA type FT-NMR (trade name) manufactured by Varian Technologies, an approximately 20% by mass resist polymer sample solution of deuterated dimethyl sulfoxide has a diameter of 5 mmφ. And 50000 times of integration using a proton complete decoupling method in which the measurement temperature is 60 ° C., the observation frequency is 125 MHz, and the nuclear overhauser effect (NOE) is removed.

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

<Light transmittance>
5 parts of the produced resist polymer and 45 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 to prepare a polymer composition solution.
The prepared polymer composition solution was spin-coated on a quartz wafer and prebaked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 1 μm.
A polymer thin film produced on a quartz wafer is placed on the sample side, and an untreated quartz wafer is placed on the reference side, and a wavelength range using an ultraviolet / visible absorptiometer UV-3100 (trade name) manufactured by Shimadzu Corporation. Was measured at 192 to 194 nm, the scan speed was set to medium speed, the sampling pitch was automatically set, and the slit width was set to 2.0, and the light transmittance at 193 nm was obtained.

3. Evaluation of Resist Composition Using the produced polymer, a resist composition was prepared as follows, and its performance was evaluated.
<Preparation of resist composition>
100 parts of the prepared resist polymer, 2 parts of triphenylsulfonium triflate as a photoacid generator, 720 parts of PGMEA as a solvent and 180 parts of ethyl lactate were mixed to obtain a uniform solution, and then the pore size was 0.1 μm. It filtered with the membrane filter and prepared the resist composition solution.

<Sensitivity>
The prepared resist composition solution was spin-coated on a silicon wafer and prebaked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 0.3 μm. Next, using a Nikon ArF excimer laser exposure machine SP-193 (product name), the exposure was changed by changing 18 points between 1 to 50 mJ / cm ² and then 110 ° C. using a hot plate. After exposure for 60 seconds, baking was performed.
Next, using the development speed analyzer RDA-790EB (product name) manufactured by Risotech Japan, the exposed wafer was put into a 2.38 mass% tetramethylammonium hydroxide aqueous solution kept at 23.5 ° C., Hold for 65 seconds.
From the data obtained by the above measurement, the exposure amount (Eth) (mJ / cm ² ) at the beginning of loss was defined as the sensitivity.

<Example 1>
In a flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer, 58.2 parts of ethyl lactate was placed under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C. while stirring.
27.20 parts of α-methacryloyloxy-γ-butyrolactone (hereinafter referred to as GBLMA) represented by the following formula (51);
26.21 parts of 2-methacryloyloxy-2-methyladamantane (hereinafter referred to as MAdMA) represented by the following formula (52);
16.42 parts of a monomer represented by the following formula (53) (hereinafter referred to as BOCNMA),

乳酸エチル１０４．７部、およびジメチル−２，２’−アゾビスイソブチレート（以下、ＤＡＩＢと言う。）２．３５５部を混合した単量体溶液の入った滴下装置から、該単量体溶液を一定速度で４時間かけてフラスコ中へ滴下した。その後、８０℃の温度を３時間保持した。

From the dropping apparatus containing a monomer solution in which 104.7 parts of ethyl lactate and 2.355 parts of dimethyl-2,2′-azobisisobutyrate (hereinafter referred to as DAIB) were mixed, The solution was dropped into the flask at a constant rate over 4 hours. Then, the temperature of 80 degreeC was hold | maintained for 3 hours.

Subsequently, the obtained reaction solution was added dropwise to 1.6 L of methanol / water = 85% by volume / 15% by volume with stirring to obtain a precipitate of a pale yellow precipitate (resist polymer Y-1). . The obtained precipitate was separated by filtration, and again poured into 1.6 L of methanol / water = 90 vol% / 10 vol% with respect to the reaction solution, and the precipitate was washed with stirring. The washed precipitate was filtered off and dried under reduced pressure at 60 ° C. for about 40 hours. Table 5 shows a result obtained by measuring properties of the obtained resist polymer Y-1.
In addition, the polymerization reaction solution was sampled every 1 hour or 1.5 hours after the start of polymerization, and the amount of unreacted monomer was determined to determine the consumption ratio of each monomer. The results are shown in Table 6.

<Example 2>
A flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer was charged with 50.8 parts of ethyl lactate under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C. while stirring.
GBLMA 25.50 parts, MAdMA 24.57 parts,
10.89 parts of a monomer represented by the following formula (54) (hereinafter referred to as HNMMA),

乳酸エチル９１．４部、およびＤＡＩＢ２．０７０部を混合した単量体溶液の入った滴下装置から、該単量体溶液を一定速度で４時間かけてフラスコ中へ滴下した。その後、８０℃の温度を３時間保持した。

From a dropping device containing a monomer solution in which 91.4 parts of ethyl lactate and 2.070 parts of DAIB were mixed, the monomer solution was dropped into the flask at a constant rate over 4 hours. Then, the temperature of 80 degreeC was hold | maintained for 3 hours.

Next, the obtained reaction solution was dropped into 1.4 L of methanol while stirring to obtain a pale yellow precipitate (resist polymer Y-2). The resulting precipitate was separated by filtration, and again poured into 1.4 L of methanol with respect to the reaction solution, and the precipitate was washed while stirring. The washed precipitate was filtered off and dried under reduced pressure at 60 ° C. for about 40 hours. Table 5 shows a result obtained by measuring properties of the obtained resist polymer Y-2.
In addition, the polymerization reaction solution was sampled every 1 hour or 1.5 hours after the start of polymerization, and the amount of unreacted monomer was determined to determine the consumption ratio of each monomer. The results are shown in Table 6.

<Comparative Example 1>
A flask equipped with a nitrogen inlet, a stirrer, a condenser, and a thermometer was charged with 52.9 parts of ethyl lactate under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C. while stirring.
GBLMA 28.05 parts, MAdMA 27.03 parts,
8.415 parts of a monomer represented by the following formula (55) (hereinafter referred to as HVN),

乳酸エチルを９５．２部、およびＤＡＩＢを２．２７７部を混合した単量体溶液の入った滴下装置から、一定速度で４時間かけてフラスコ中へ滴下した。その後、８０℃の温度を３時間保持した。

From a dropping device containing a monomer solution in which 95.2 parts of ethyl lactate and 2.277 parts of DAIB were mixed, it was dropped into the flask at a constant rate over 4 hours. Then, the temperature of 80 degreeC was hold | maintained for 3 hours.

Subsequent operations were performed in the same manner as in Example 2 to obtain a resist polymer B-2. Table 5 shows a result obtained by measuring properties of the obtained resist polymer B-2.
In addition, the polymerization reaction solution was sampled every 1 hour or 1.5 hours after the start of polymerization, and the amount of unreacted monomer was determined to determine the consumption ratio of each monomer. The results are shown in Table 7.

The resist polymer of the present invention (Examples 1 and 2) was excellent in copolymerizability and light transmittance at the exposure wavelength. Moreover, the resist composition (Examples 1 and 2) using the resist polymer of the present invention had sufficient sensitivity.
On the other hand, the resist polymer of Comparative Example 1 containing no structural unit (A) was inferior in light transmittance at the exposure wavelength.

<Example 3>
For the resist polymer Y-2 produced in Example 2, in order to evaluate the solubility of the exposed resist polymer in the developer, the particle size distribution of the developer in which the resist composition was dissolved (with water) The particle size distribution of the developer before dilution) and the particle size distribution of a solution obtained by diluting the developer in which the resist composition was dissolved with water (particle size distribution of the developer after dilution with water) were determined.
The apparatus used was a dense particle size analyzer FPAR-1000 (high sensitivity type) (trade name) manufactured by Otsuka Electronics. The measurement temperature was 25 ° C. and the measurement time was 120 seconds.
Moreover, the data processing method was performed using the Marquad method in the range of a particle diameter of 10 nm to 100,000 nm (= 100 μm).

If the particle size distribution of the developer before diluting with water is the same as the particle size distribution of the developer after diluting with water, dissolve the exposed resist polymer in the developer. In this case, it has been found that there are few development defects such as defects.
On the other hand, compared to the particle size distribution of the developer before diluting with water, the particle size distribution of the developer after diluting with water shows a peak on the large particle size side or When the ratio of the peak area is relatively large, it means that the solubility of the exposed resist polymer in the developer is poor, and from the above examination, in such a case, It has been found that there are many development defects such as defects.
Therefore, development defects such as defects can be predicted by comparing the particle size distribution of the developer before diluting with water and the particle size distribution after developing with water.

Specifically, the resist composition solution prepared in Example 2 was spin-coated on a 6-inch silicon wafer, pre-baked at 120 ° C. for 60 seconds using a hot plate, and a 0.3 μm-thick resist. A membrane was produced.
Next, using an as-one handy UV lamp SUV-4 (trade name) (wavelength 254 nm), the distance between the irradiated surface and the wafer was set to 5 cm, exposed for 20 seconds, and then heated at 110 ° C. for 60 seconds using a hot plate. Post-exposure baking was performed.
Then, the silicon wafer on which the resist film was formed was immersed for 60 seconds in a glass petri dish containing 100 parts of an aqueous 2.38 mass% tetramethylammonium hydroxide kept at 23 ° C., and developed.
Using the above developer, resist film formation, heat treatment, exposure, and development are repeated under the same conditions as described above to develop a silicon wafer on which 15 resist films have been formed. A dissolved developer G-1 was prepared.

FIG. 1 shows the results of particle size distribution measurement of the developer G-1 prepared by the above operation and a 10% by mass aqueous solution of the developer G-1.
The developer obtained by exposing the resist composition using the resist polymer Y-2 is almost the same in the particle size distribution before dilution with water and the particle size distribution after dilution with water. Distribution. Therefore, it is expected that the exposed resist polymer has good solubility in a developing solution, and there are few development defects such as defects.

<Comparative example 2>
A developer F-1 was prepared in the same manner as in Example 3 except that the resist polymer was changed to that produced in Comparative Example 1 (Polymer B-2).
And the result of having implemented the particle size distribution measurement of the developing solution F-1 and the 10 mass% aqueous solution of the developing solution F-1 is shown in FIG.

<Reference Example 1>
The molar absorption constant (1 / mol · cm) of the compound of the following formula (61) (model structure of the structural unit obtained by polymerization using the monomer of formula (55)) is calculated by Fujitsu's computational chemistry software CAChe (product) Name).

  Specifically, the molar absorption constant of the formula (61) is obtained by using the atoms constituting the formula (61) and the bond type (a bond type such as a single bond, a double bond, and a triple bond) as a two-dimensional information. The input modeling is performed, and the structure optimization is performed based on the two-dimensional information by arranging the atoms and bond species in three dimensions so that the potential energy between atoms is minimized by the PM3 method. Then, by calculating the molar absorption constant in the ultraviolet-visible region between each atom whose structure is optimized by the ZINDO-CI PM3 method and summing up in all wavelength regions, the molar absorption constant at an arbitrary wavelength can be obtained. it can. The smaller the molar absorption constant, the better the light transmittance at that wavelength.

  The specific operation method of the structure optimization of the PM3 method by the Fujitsu computational chemistry software CAChe (product name) is as follows. After modeling the structural unit on the Workspace screen of the Fujitsu computational chemistry software CAChe (product name), Select “New” from the pull-down menu of “Experiment”, and in the newly appearing screen, the item “Profession of ::” is “chemical sample”, the item “Property:” is “optimized geometry”, and “Usage: The item “” is to select “Start” after selecting “PM3 geometry”, and the structure can be optimized by this operation.

A specific operation method for obtaining the molar extinction constant according to the ZINDO-CI PM3 method is to appear newly by selecting “New” from the pull-down menu of “Experiment” with the structure optimized by the PM3. In the screen, the item “Profession of:” is “chemical sample”, the item “Property:” is “UV-visible transitions”, and the item “Using:” is “ZINDO-CI at PM3 geometry”. In the ultraviolet-visible absorption spectrum displayed by selecting “Start” after selecting, and selecting “UV-visible transitions” from the “Analyze” pull-down menu after completing the calculation. It can be determined molar extinction constant at 193 nm.
As a result of the above operation, the molar absorption constant at 193 nm of the compound of the formula (61) was 600 (1 / mol · cm).

<Reference Example 2>
The molar absorption constant (1 / mol · cm) at 193 nm of the compound of the following formula (62) (model structure of the structural unit obtained by polymerization using the monomer of the formula (8-1)) As in the case of No. 3, the result of calculation using Fujitsu's computational chemistry software CAChe (product name) was 800 (1 / mol · cm).

  Polymer for resist Y-2 having a molar absorption coefficient (600 (1 / mol · cm)) at 193 nm of the model compound represented by the formula (61) and a structural unit corresponding to this model compound (Example 2) ), The polymer having a structural unit corresponding to the model compound represented by the formula (62) (molar extinction coefficient at 193 nm = 800 (1 / mol · cm)) The light transmittance at 193 nm is expected to be good, and the sensitivity or resolution when used as a resist composition is expected to be good.

  However, since the molar extinction coefficient of the model compound represented by the formula (62) is larger than the molar extinction coefficient of the model compound represented by the formula (61), the model compound represented by the formula (61) When the resist polymer Y-2 (Example 2) having a structural unit corresponding to is compared with the resist polymer having a structural unit corresponding to the model compound represented by the formula (62), the resist weight The combined Y-2 is expected to have better sensitivity or resolution when used as a resist composition.

Particle size distribution of developer G-1 (Example 3) Particle size distribution of developer F-1 (Comparative Example 2)

Claims (5)

Resist material comprising a resist polymer that decomposes by the action of an acid, containing a structural unit having a naphthalene skeleton represented by the following formula (1-3) (excluding the structures of the following formulas (A) to ( D )) .

(In the formula (1-3), R ¹⁰ represents a hydrogen atom or a methyl group, and G represents either —C (═O) —O—, —O—, or —O—C (═O) —. G3 represents 0 or 1. Y represents —C (═O) —OH, —OH, —C (═O) —OR ¹³ , or —OR ¹³ , and R ¹³ represents 1 to 1 carbon atoms. 20 represents a straight-chain, branched or cyclic hydrocarbon group, and this hydrocarbon group may have a hetero atom, and L ¹ ′ is a straight-chain, branched or Represents a cyclic divalent hydrocarbon group, and this divalent hydrocarbon group may have a hetero atom.)

(In formulas (A) to (D), R represents a hydrogen atom or an acid labile group.) In the formula (1-3), G is —C (═O) —O—, g3 is 0, and L ¹ ′ is L ¹ ″. Therefore, the resist polymer is represented by the following formula (1- 4. A resist material comprising a resist polymer that decomposes by the action of an acid according to claim 1, comprising a structural unit having a naphthalene skeleton shown in 4) (excluding the structures of the following formulas (A) to ( D )): .

(In Formula (1-4), R ¹⁰ represents a hydrogen atom or a methyl group. Y represents —C (═O) —OH, —OH, —C (═O) —OR ¹³ , or —OR ^13. R ¹³ represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms, and this hydrocarbon group may have a hetero atom. L ¹ ″ represents 1 carbon atom. Represents a linear hydrocarbon group of ˜4.)

(In formulas (A) to (D), R represents a hydrogen atom or an acid labile group.)
In the formula (1-4), Y is a hydroxyl group, and therefore the resist polymer has a naphthalene skeleton represented by the following formula (1-5) (however, the following formulas (A) to ( D )): A resist material comprising a resist polymer that decomposes by the action of an acid according to claim 2, which contains a structure).

(In formula (1-5), R ¹⁰ represents a hydrogen atom or a methyl group, and L ¹ ″ represents a straight-chain hydrocarbon group having 1 to 4 carbon atoms.)

(In formulas (A) to (D), R represents a hydrogen atom or an acid labile group.)   The resist composition containing the resist material in any one of Claims 1-3.   A substrate on which a pattern including a step of applying the resist composition according to claim 4 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 is formed. Production method.

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