JP2008133312A - Polymer, resist composition and method for producing substrate formed with pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polymer having a high sensitivity, a high resolution, a high light transmittance and little elution of a quencher from a resist composition during a liquid immersion exposure in use as a resist composition for liquid immersion exposure of lithography using a DUV excimer laser and a resist composition and to provide a method for producing a substrate formed with a pattern. <P>SOLUTION: The polymer for a resist comprises a constituent unit (M) having a specific amine backbone. The resist composition comprises the polymer. The method for producing a substrate formed with a pattern comprises a process for coating a substrate with the resist composition to form a resist film, a process for exposure with a light at a wavelength of ≤250 nm in a state in which an immersion liquid is laid between the resist film and the final lens of an exposure device and a process for development with a developer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

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 miniaturization technique, in general, miniaturization is attempted by shortening the wavelength of irradiation light used for creating a pattern. Specifically, the irradiation light has been changed from conventional ultraviolet rays typified by g-line (wavelength: 438 nm) and i-line (wavelength: 365 nm) to shorter wavelength DUV (Deep Ultra Violet).
At present, lithography technology using a KrF excimer laser (wavelength: 248 nm) is introduced into the market, and lithography technology using an ArF excimer laser (wavelength: 193 nm) with a shorter wavelength is also being introduced into the market. Further, a lithography technique using a short wavelength F ₂ excimer laser (wavelength: 157 nm) and an EUV excimer laser (wavelength: 13 nm) has been studied. On the other hand, immersion lithography technology that can achieve high resolution and wide depth of focus is also being actively researched for market introduction. Also, as a different type of lithography technology, electron beam lithography technology has been energetically studied.

As a high-resolution resist using irradiation light or an electron beam of the short wavelength described above, a chemically amplified resist containing a photoacid generator has been proposed, and improvement and development of this chemically amplified resist are currently being promoted. ing.
For example, as a polymer for a chemically amplified resist used in lithography using an ArF excimer laser, an acrylic polymer that is transparent to light having a wavelength of 193 nm is widely used. As such an acrylic polymer, for example, Patent Document 1 and Patent Document 2 include (meth) acrylic acid ester having an adamantane skeleton in an ester portion and (meth) acrylic acid ester having a lactone skeleton in an ester portion. A polymer is disclosed.

  Usually, when these acrylic polymers are used as a resist composition, the quencher disclosed in Patent Document 3 or the like is used to suppress the influence of standing waves and obtain a good pattern shape of the resist. A so-called nitrogen-containing base compound is added. However, when this resist composition is used for immersion exposure using pure water or the like as an immersion liquid, the quencher may elute into the immersion liquid, which may adversely affect the pattern shape. Further, there is a concern that the quencher eluted into the immersion liquid adheres to the lens of the exposure machine, thereby impairing the pattern transfer property or causing a decrease in throughput.

Patent Document 4 discloses a high-resolution resist composition containing an acrylic polymer having an iminodiketone skeleton. However, since the ultraviolet absorption amount of the amide bond is relatively large, the light transmittance of the excimer laser may not be sufficient. As a result, there is a concern that the sensitivity and throughput of the resist composition may be reduced.
JP 10-319595 A JP-A-10-274852 JP 2005-309457 A JP 2006-063318 A

The present invention, when used as a resist composition for immersion exposure such as lithography using a DUV excimer laser, has high sensitivity, high resolution, high light transmittance, and a quenching from the resist composition during immersion exposure. An object is to provide a polymer with less char elution.
Furthermore, it aims at providing the manufacturing method of the resist composition containing the said polymer, and the board | substrate with which the pattern was formed using this resist composition.

（式（１）中、Ｒ¹⁰は水素原子又はメチル基を表す。Ｇは単結合、−Ｃ(＝Ｏ)−Ｏ−、−Ｏ−又は−Ｏ−Ｃ(＝Ｏ)−のいずれかを表す。Ｌは単結合又は炭素数１〜２０の直鎖、分岐若しくは環状の２価の炭化水素基を表す。この２価の炭化水素基は置換基及び／又はヘテロ原子を有していてもよい。また、この２価の炭化水素基は、−Ｃ（＝Ｏ）−Ｏ−又は−Ｏ−Ｃ（＝Ｏ）−のいずれかを含んでいてもよい。Ｒ¹¹、Ｒ¹²はそれぞれ独立して、水素原子又は炭素数１〜２０の直鎖、分岐若しくは環状の１価の炭化水素基を表す。この１価の炭化水素基は置換基及び／又はヘテロ原子を有していてもよい。さらに、ＬとＲ¹¹、ＬとＲ¹²、又はＲ¹¹とＲ¹²とが、一緒になって鎖長１〜６の環状のメチレン鎖（−（ＣＨ₂）_k−（ｋは１〜６の整数を表す））を形成してもよく、この環状のメチレン鎖は置換基及び／又はヘテロ原子を有してもよい。） A first invention for solving the above problems is a resist polymer containing a structural unit (M) having an amine skeleton represented by the following formula (1) (hereinafter referred to as “polymer (P)”). ).

(In the formula (1), R ¹⁰ represents a hydrogen atom or a methyl group. G represents a single bond, —C (═O) —O—, —O— or —O—C (═O) —. L represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, which may have a substituent and / or a hetero atom. The divalent hydrocarbon group may contain either —C (═O) —O— or —O—C (═O) —, wherein R ¹¹ and R ¹² are independent of each other. Represents a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms, and this monovalent hydrocarbon group may have a substituent and / or a hetero atom. Furthermore, L and R ¹¹ , L and R ¹² , or R ¹¹ and R ¹² are combined to form a cyclic methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _k — (k is 1 to 6). Integer And this cyclic methylene chain may have a substituent and / or a heteroatom.)

The second invention is a resist composition for immersion exposure containing a polymer (P).
Furthermore, the third invention is a step of coating the resist composition on a substrate to form a resist film, with an immersion liquid interposed between the resist film and the final lens of the exposure apparatus, and a thickness of 250 nm or less. It is the manufacturing method of the board | substrate with which the pattern which has the process exposed with the light of this wavelength, and the process developed with a developing solution was formed.

The resist composition of the present invention has high sensitivity and high resolution when used in lithography using a DUV excimer laser, etc., high light transmittance, and little quencher elution from the resist composition during immersion exposure . Therefore, the polymer (P) of the present invention is suitable as a polymer for a resist for microfabrication used in the production of semiconductor elements.
In addition, the polymer (P) and the resist composition of the present invention use lithography using a DUV excimer laser, immersion lithography and electron beam lithography, particularly lithography using an ArF excimer laser, immersion lithography, and a mercury lamp. It is suitable for lithography and this immersion lithography.
Furthermore, a substrate on which a highly accurate fine pattern is formed can be obtained with a good yield according to the present invention.
The polymer (P) of the present invention is a resist composition for immersion exposure for various uses such as semiconductor manufacturing, metal etching, photofabrication, plate making, hologram, color filter, retardation film, etc. It can be suitably used as a product.

Structural unit (M)

In the present invention, the structural unit (M) having an amine skeleton represented by the formula (1) is included as a structural unit of the polymer (P).
G in Formula (1) represents a single bond, —C (═O) —O—, —O— or —O—C (═O) —. G is preferably —C (═O) —O— or —O—C (═O) — in terms of polymerizability, and is preferably a single bond or —O in terms of heat resistance of the polymer (P). -Is preferred.

L in Formula (1) represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms. This divalent hydrocarbon group may have a substituent and / or a hetero atom. In addition, the divalent hydrocarbon group may contain either —C (═O) —O— or —O—C (═O) —.
L is a single bond, a linear or branched divalent hydrocarbon group having 1 to 4 carbon atoms, and — (CH ₂ CH ₂ O) in view of solubility of the polymer (P) in an organic solvent. _g1 - or _{- (CH 2 CH (CH 3} ) O) g2 - are preferred. Here, g1 and g2 each represent an integer of 1 to 5, and 1 or 2 is preferable in terms of the resolution of the resist composition.
L is preferably at least one selected from the formulas (2-1) to (2-4) in terms of dry etching resistance of the resist.

In formulas (2-1) to (2-4), R ²¹¹ , R ²¹² , R ²¹³ , R ²¹⁴ , R ²¹⁵ and R ²¹⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Z is an atomic group constituting a cyclic hydrocarbon group in L.
In the formulas (2-1) to (2-4), the upper left bond is bonded to G, and the lower right bond is bonded to a nitrogen atom.

Further, when G is —C (═O) —O—, L represents —C (CH ₃ ) ₂ —, —C (CH ₃ ) ₂ —CH ₂ —, — in terms of the sensitivity of the resist composition. At least one selected from C (CH ₃ ) (CH ₂ CH ₃ ) —, formula (2-1) and formula (2-2) is more preferable.
R ¹¹ and R ¹² each independently represents a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms. This monovalent hydrocarbon group may have a substituent and / or a hetero atom. Further, L and R ¹¹ , L and R ¹² , or R ¹¹ and R ¹² are combined together to form a cyclic methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _k — (k is 1 to 6). Which represents an integer))), and this cyclic methylene chain may have substituents and / or heteroatoms.

The structural unit (M) can be used alone or in combination of two or more.
Further, the content of the structural unit (M) is preferably 0.01 mol% or more, more preferably 0.1 mol% or more in the structural unit of the polymer (P) in terms of resist pattern rectangularity and line edge roughness. More preferred. In addition, the content of the structural unit (M) is preferably 30 mol% or less, more preferably 25 mol% or less, and further preferably 20 mol% or less in terms of the sensitivity of the resist composition and the adhesion to the substrate surface. preferable.

  Examples of the structural unit (M) include structural units represented by formulas (1-1) to (1-12). In formula (1-1) to formula (1-12), R represents a hydrogen atom or a methyl group.

Polymer (P)

The mass average molecular weight of the polymer (P) is preferably 1,000 or more, more preferably 2,000 or more, and still more preferably 3,000 or more, from the viewpoint of dry etching resistance and pattern shape of the resist.
In addition, the mass average molecular weight of the polymer (P) is preferably 100,000 or less, more preferably 50,000 or less in terms of the solubility of the polymer (P) in the resist composition solution and the resolution of the resist composition. 30,000 or less is more preferable, and 20,000 or less is particularly preferable.

  The molecular weight distribution (Mw / Mn) of the polymer (P) is preferably 2.5 or less, and preferably 2.3 or less in terms of the solubility of the polymer (P) in the resist composition solution and the resolution of the resist composition. More preferred is 2.0 or less.

In the present invention, the polymer (P) may have a structural unit (A) having a lactone skeleton, an lactone skeleton and a naphthalene skeleton, and an acid leaving group (decomposed or eliminated by the action of an acid, if necessary. A structural unit (B) having a lactone skeleton, an acid-eliminable group, and a structural unit (C) having a hydrophilic group without a naphthalene skeleton, and a structural unit having a naphthalene skeleton without a lactone skeleton ( Other structural units such as D) can be contained.

Structural unit (A)

The polymer (P) preferably contains a structural unit (A) having a lactone skeleton in terms of adhesion of the resist composition to the substrate surface and the like.
The structural unit (A) is not particularly limited as long as it includes a structure having a cyclic saturated hydrocarbon containing a carbonyloxy group (—C (═O) —O—) in the ring.
The structural unit (A) can be used alone or in combination of two or more.
The content of the structural unit (A) is preferably 25 mol% or more, more preferably 30 mol% or more with respect to the total structural units of the polymer (P) in terms of adhesion of the resist composition to the substrate surface and the like. preferable. Further, the content of the structural unit (A) is preferably 65 mol% or less, more preferably 60 mol% or less, with respect to all the structural units of the polymer (P) in terms of sensitivity and resolution of the resist composition. 55 mol% or less is more preferable.

Further, when the structural unit (A) has an acid-eliminable group, the adhesion and sensitivity of the resist composition to the substrate surface and the like tend to be more excellent.
Examples of the acid leaving group include those similar to the structural unit (B) described later.
Moreover, when the structural unit (A) has a hydrophilic group, the sensitivity of the resist composition tends to be better and the resist pattern rectangularity tends to be better.
Examples of the hydrophilic group include those similar to the structural unit (C) described later.
Furthermore, when the structural unit (A) has a naphthalene skeleton, process margins such as substrate adhesion and depth of focus of the resist composition tend to be good.
Examples of the structural unit having a naphthalene skeleton include the same structural units (D) described later.

In order to make the resist composition containing the polymer (P) particularly suitable for lithography including a step of exposing with light having a wavelength of 250 nm or less, the structural unit (A) includes (meth) acrylate, A structural unit derived from α-fluorine-substituted (meth) acrylate or α-methylene is preferred.
Here, α-fluorine-substituted (meth) acrylate is α-fluoro methacrylate in which a hydrogen atom of a methyl group bonded to a carbon atom at α-position of methacrylic acid is substituted with a fluorine atom and / or hydrogen at α-position of acrylic acid. It means α-fluoroacrylate in which an atom is substituted with a fluorine atom.
The structural unit derived from (meth) acrylate, α-fluorine-substituted (meth) acrylate or α-methylene uses (meth) acrylate, α-fluorine-substituted (meth) acrylate or α-methylene as a monomer. Means that
In the present invention, (meth) acrylate and (meth) acrylic acid mean methacrylate or acrylate and methacrylic acid or acrylic acid, respectively.

  As the structural unit (A), at least one selected from the group consisting of formulas (4-1) to (4-6) is preferable in terms of the sensitivity of the resist composition or the dry etching resistance of the resist.

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

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

R ²⁰¹ , R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ⁹³ , R ⁹⁴ , R ²⁰⁸ and R ²⁰⁹ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxy group, a carboxy group or A carboxy group esterified with an alcohol having 1 to 6 carbon atoms is represented.

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

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

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

  i represents 0 or 1; m and m1 represent 1 or 2.

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

In addition, A ¹ and A ² in the formula (4-2) preferably represent —CH ₂ — or —CH ₂ CH ₂ — together with respect to the dry etching resistance of the resist. From the viewpoint of solubility of P) in an organic solvent, it is preferable to represent -O- together.
R ²⁰¹ and R ²⁰² are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of solubility of the polymer (P) in an organic solvent.
n6 is preferably 0 in terms of resistance to dry etching of the resist.

A ³ and A ⁴ in the formula (4-3) preferably represent —CH ₂ — or —CH ₂ CH ₂ — together with respect to the dry etching resistance of the resist, and the polymer (P) From the viewpoint of solubility in an organic solvent, it is preferable to represent -O- together.
R ²⁰³ and R ²⁰⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of solubility of the polymer (P) in an organic solvent.
n7 is preferably 0 from the viewpoint of dry etching resistance of the resist.

In formula (4-4), R ²⁰⁵ , R ²⁰⁶ and R ²⁰⁷ are preferably hydrogen atoms from the viewpoint of solubility of the polymer (P) in an organic solvent.
Y ¹¹ , Y ¹² and Y ¹³ are in terms of adhesion of the resist composition to the substrate surface, etc., one is —C (═O) —O— and the other two are —CH ₂ —. Is preferred.
n8 is preferably 0 in terms of dry etching resistance of the resist.

In formula (4-5), R ⁹¹ , R ⁹² , R ⁹³ and R ⁹⁴ are each independently preferably a hydrogen atom or a methyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
Further, m1 is preferably 1 in terms of sensitivity and resolution of the resist composition.

In formula (4-6), A ⁵ and A ⁶ preferably represent together —CH ₂ — or —CH ₂ CH ₂ — in terms of resistance to dry etching of the resist. Polymer (P) From the viewpoint of solubility in an organic solvent, it is preferable to represent -O- together.
R ²⁰⁸ , R ²⁰⁹ , R ²¹⁰ and R ²¹¹ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
Y ²¹ and Y ²² are preferably —C (═O) —, and the remaining one is preferably —CH ₂ — in terms of adhesion of the resist composition to the substrate surface and the like.
n9 is preferably 0 in terms of resistance to dry etching of the resist.

  The polymer (P) having the structural unit (A) can be produced by polymerizing a monomer containing the monomer (a) that gives the structural unit (A).

  Examples of the monomer (a) include monomers represented by formulas (10-1) to (10-29). In formula (10-1) to formula (10-29), R represents a hydrogen atom or a methyl group.

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

Structural unit (B)

Further, the polymer (P) preferably contains a structural unit (B) having an acid leaving group in order to make the resist composition excellent in sensitivity.
The acid leaving group is generally contained in a chemically amplified resist composition. The acid leaving group in the acid leaving group is generated by the action of an acid generated from a photoacid generator that generates an acid by light irradiation (exposure). The bond is cleaved, and part or all of the acid leaving group is separated or eliminated from the main chain of the polymer.
Accordingly, in the structural unit (B), the polymer (P) is made insoluble in alkali before part or all of the acid leaving group is eliminated, and part or all of the acid leaving group is eliminated by the acid. By doing so, it is a component that makes the polymer (P) alkali-soluble. In addition, the structural unit (B) has an effect of enabling resist pattern formation in a positive chemically amplified resist.
By containing the structural unit (B), the polymer (P) is suitable for a chemically amplified resist.
Chemically amplified resists include a positive type in which an exposed portion is soluble in a developer (alkaline aqueous solution) and a negative type in which an exposed portion is insoluble in a developer.

The structural unit (B) can be used alone or in combination of two or more.
The content of the structural unit (B) is preferably 20% by mole or more, more preferably 25% by mole or more based on the total structural unit of the polymer (P) in terms of sensitivity and resolution of the resist composition. Further, the content of the structural unit (B) is preferably 70 mol% or less, and preferably 65 mol% or less with respect to all the structural units of the polymer (P) in terms of adhesion of the resist composition to the substrate surface and the like. Is more preferable, and 60 mol% or less is still more preferable.

Further, when the structural unit (B) has a hydrophilic group, it tends to have a higher sensitivity of the resist composition.
Examples of the hydrophilic group include those similar to the structural unit (C) described later.

  In order to make the resist composition containing the polymer (P) particularly suitable for lithography including a step of exposing with light having a wavelength of 250 nm or less, as the structural unit (B), the structural unit (A ), A structural unit derived from (meth) acrylate or α-fluorine-substituted (meth) acrylate is preferred.

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

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

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

R ³³¹ , R ³³² , R ³³³ , R ³³⁴ , R ³⁵¹ , R ³⁵² , R ³⁵³ , R ³⁵⁴ , R ³⁶¹ , R ³⁶² , R ³⁶³ and R ³⁶⁴ are each independently a hydrogen atom or a straight chain having 1 to 6 carbon atoms. Represents a chain or branched alkyl group.
V ¹ , V ² , V ³ , V ⁴ , V ⁵ and V ⁶ are each independently —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _u1 — (U1 represents an integer of 1 to 6)).
q, q3, and q4 represent 0 or 1. r represents an integer of 0-2.

R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ each independently represent a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. And at least one of R ³⁵⁵ , R ³⁵⁶ and R ^{357 is} an alicyclic hydrocarbon group or a derivative thereof, or any two of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ are bonded to each other, The remaining one of R ³⁵⁵ , R ³⁵⁶ and R ³⁵⁷ that did not participate in the bond, together with the bonded carbon atom, formed a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof. Represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof.

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

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 of the resist composition.
N1 is preferably 0 in terms of resistance to dry etching of the resist.

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

R ⁴ in formula (3-3-1) is preferably a methyl group, an ethyl group, or an isopropyl group from the viewpoint of sensitivity and resolution of the resist composition.
V ¹ and V ² are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the standpoint of resistance to dry etching of the resist.
R ³³¹ , R ³³² , R ³³³ and R ³³⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
n3 is preferably 0 in terms of dry etching resistance of the resist.
Further, q is preferably 1 in terms of resistance to dry etching of the resist, and is preferably 0 in terms of solubility of the polymer (P) in an organic solvent.

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

V ³ and V ^{4 in} formula (3-5-1) are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the standpoint of dry etching resistance of the resist.
R ³⁵¹ , R ³⁵² , R ³⁵³ and R ³⁵⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of solubility of the polymer (P) in an organic solvent.
n51 is preferably 0 in terms of resistance to dry etching of the resist.
Q3 is preferably 1 in terms of resistance to dry etching of the resist, and is preferably 0 in terms of solubility of the polymer (P) in an organic solvent.
Further, -C (R ³⁵⁵ ) (R ³⁵⁶ ) (R ³⁵⁷ ) is preferably a structure represented by formula (K-1) to formula (K-6) in terms of the line edge roughness of the resist. From the viewpoint of dry etching resistance, a structure represented by formula (K-7) to formula (K-17) is preferable.

In formula (3-6-1), V ⁵ and V ⁶ are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the viewpoint of dry etching resistance of the resist.
R ³⁶¹ , R ³⁶² , R ³⁶³ and R ³⁶⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of solubility of the polymer (P) in an organic solvent.
n61 is preferably 0 in view of dry etching resistance of the resist.
Q4 is preferably 1 in terms of resistance to dry etching of the resist, and 0 is preferably in terms of solubility of the polymer (P) in an organic solvent.
Further, -C (R ³⁶⁵ ) (R ³⁶⁶ ) -O-R ³⁶⁷ is preferably a structure represented by formula (J-1) to formula (J-24) in terms of line edge roughness of the resist. From the viewpoint of dry etching resistance, a structure represented by formula (J-25) to formula (J-52) is preferable.

-C (R ³⁷¹ ) (R ³⁷² ) -O-R ³⁷³ in the formula (3-7-1) is a point of line edge roughness of the resist, and is represented by the formulas (J-1) to (J-24). The structure represented is preferred. Moreover, the structure represented by Formula (J-25)-Formula (J-52) is preferable at the point of the dry etching tolerance of a resist.

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

  Furthermore, n-butoxyethyl (meth) acrylate, iso-butoxyethyl (meth) acrylate, etc. are mentioned as a monomer (b).

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

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

  In terms of resistance to dry etching of the resist, the equations (9-41) to (9-51), the equations (9-63) to (9-75), and the equations (9-89) to (9- 101), formula (9-136) to formula (9-146), formula (9-158) to formula (9-170) and formula (9-184) to formula (9-196) And their geometric and optical isomers are preferred.

  Moreover, the monomer represented by Formula (9-197)-Formula (9-224) and these geometrical isomers and optical isomers are preferable at the point of the pattern rectangularity of a resist.

Furthermore, as a specific example of the monomer (b), α-fluoromethyl acrylate in which a hydrogen atom of a methyl group bonded to a carbon atom at the α-position of methacrylic acid is substituted with a fluorine atom or a hydrogen atom at the α-position of acrylic acid Α-fluorine-substituted (meth) acrylate in which is substituted with a fluorine atom.
Specific examples of the monomer include tert-butyl α-trifluoromethyl acrylate, methoxymethyl α-trifluoromethyl acrylate, ethoxyethyl α-trifluoromethyl acrylate, and n-propoxyethyl α-trifluoromethyl acrylate. , Iso-propoxyethyl α-trifluoromethyl acrylate, n-butoxyethyl α-trifluoromethyl acrylate, iso-butoxyethyl α-trifluoromethyl acrylate, tert-butoxyethyl α-trifluoromethyl acrylate, tert-butyl α- Fluoroacrylate, methoxymethyl α-fluoroacrylate, ethoxyethyl α-fluoroacrylate, n-propoxyethyl α-fluoroacrylate, iso-propoxyethyl α-fu Oro acrylate, n- butoxyethyl α- fluoro acrylate, iso- butoxy α- fluoroacrylate and tert- butoxyethyl α- fluoroacrylate.

Further, as the monomer (b), in addition to the above, 2-methyl-2,4-butanediol di (meth) acrylate, 2,5-dimethyl-2,5-hexanediol di (meth) acrylate, 1 , 4-butanediol di (1- (meth) acryloyloxy) ethyl ether, 1,4-butanediol di (1- (meth) acryloyloxy) methyl ether, (meth) acryloyloxyethylene glycol dimer (1- (meta And polyfunctional (meth) acrylates such as (acryloyloxy) ethyl ether and (meth) acryloyloxyethylene glycol dimer (1- (meth) acryloyloxy) methyl ether).

Structural unit (C)

The polymer (P) preferably contains a structural unit (C) having a hydrophilic group, from the viewpoint of reducing defects in the resist composition and resist pattern rectangularity.
Examples of the hydrophilic group include —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a methoxy group, a carboxy group, and an amino group. The structural unit (C) is one kind or a combination of two or more kinds. Can be used.

  The content of the structural unit (C) is preferably from 3 to 35 mol%, more preferably from 5 to 30 mol%, based on the total structural units of the polymer (P) in terms of the resist pattern rectangularity.

  In order to make the resist composition containing the polymer (P) particularly suitable for lithography including a step of exposing with light having a wavelength of 250 nm or less, as the structural unit (C), (meth) acrylate or A structural unit derived from α-fluorinated (meth) acrylate is preferred.

  The structural unit (C) is preferably at least one selected from the group consisting of formulas (5-1) to (5-7) in terms of dry etching resistance of the resist.

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

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

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

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

R ^{531 to} R ⁵³⁶ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. W ¹ , W ² and W ³ are each independently —O—, —S—, —NH— or a methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _u2 — (u2 is an integer of 1 to 6). Represents)).

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

^R571 represents a carbon atom having a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms, or a bridged cyclic hydrocarbon group having 4 to 16 carbon atoms. 1 to 6 linear or branched alkyl groups are represented.
R ⁵⁷² is a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, or a bridged ring having 4 to 16 carbon atoms together with the carbon atoms to which R ⁵⁷¹ and R ⁵⁷² are bonded together. A formula hydrocarbon group may be formed.
Here, the alkyl group in R ⁵⁷¹ and R ⁵⁷² may have a hydroxy group, a carboxy group, an acyl group having 2 to 6 carbon atoms, or a carboxy group esterified with an alcohol having 1 to 6 carbon atoms. Moreover, the bridged cyclic hydrocarbon group in ^R571 and ^R572 may have a linear or branched alkyl group having 1 to 6 carbon atoms, and the alkyl group includes a hydroxy group, a carboxy group, and a carbon number of 2 It may have a carboxy group esterified with a -6 acyl group or an alcohol having 1 to 6 carbon atoms.

R ⁵⁰¹ in formula (5-1) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
Further, n51 is preferably 1 from the viewpoint of resist dry etching resistance.
X ⁵¹ is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.

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

R ⁵⁰² in formula (5-3) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
W ¹ and W ² are each preferably —CH ₂ — or —CH ₂ CH ₂ — independently from the viewpoint of dry etching resistance of the resist.
R ⁵³¹ , R ⁵³² , R ⁵³³ and R ⁵³⁴ are each independently preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
Further, n53 is preferably 1 from the viewpoint of dry etching resistance of the resist.
X ⁵³ is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.
Q1 is preferably 1 from the viewpoint of dry etching resistance of the resist, and 0 is preferable from the viewpoint of solubility of the polymer (P) in an organic solvent.

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

In formula (5-5), R ⁵⁰⁴ and R ⁵⁰⁵ are each independently preferably a methyl group, an ethyl group or an isopropyl group from the viewpoint of sensitivity and resolution of the resist composition.
Further, n55 is preferably 1 from the viewpoint of resist dry etching resistance.
X ⁵⁵ is preferably a —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.

R ⁵⁰⁶ in formula (5-6) is preferably a methyl group, an ethyl group or an isopropyl group in terms of the sensitivity and resolution of the resist composition, and in terms of the solubility of the polymer (P) in an organic solvent, A hydrogen atom is preferred.
W ³ is preferably —CH ₂ — or —CH ₂ CH ₂ — in terms of dry etching resistance of the resist.
R ⁵³⁵ and R ⁵³⁶ are preferably a hydrogen atom, a methyl group, an ethyl group or an isopropyl group from the viewpoint of the solubility of the polymer (P) in an organic solvent.
Further, n56 is preferably 1 in terms of resistance to dry etching of the resist.
X ⁵⁶ is preferably —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, or a methoxy group in terms of the resist pattern shape.
Q2 is preferably 1 from the viewpoint of dry etching resistance of the resist, and 0 is preferable from the viewpoint of solubility of the polymer (P) in an organic solvent.

R ⁵⁷¹ and R ⁵⁷² in the formula (5-7) are, in terms of dry etching resistance of the resist, R ⁵⁷¹ and R ⁵⁷² are combined to form a carbon atom having 4 to 16 carbon atoms together with the carbon atom to which each is bonded. A structure in which a crosslinked cyclic hydrocarbon group is formed is preferable. In addition, in terms of heat resistance and stability of the resist, R ⁵⁷¹ and R ⁵⁷² are combined together to form a ring structure contained in the bridged cyclic hydrocarbon group formed together with the carbon atom to which each is bonded. It preferably has 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.
Furthermore, X ⁵⁷ is in terms of resist pattern _{shape, -C (CF 3) 2 -OH} , -CH 2 -OH, -CH 2 -CN, -CH 2 -O-CH 3 or - (CH _{2) 2} -O-CH ₃ are preferred.

  The polymer (P) having the structural unit (C) can be produced by polymerizing a monomer containing the monomer (c) that gives the structural unit (C).

  Examples of the monomer (c) include monomers represented by formulas (13-1) to (13-79). In formula (13-1) to formula (13-79), R represents a hydrogen atom or a methyl group.

  Moreover, as monomer (c), in addition to the above, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy-n-propyl (meth) acrylate and 4-hydroxy-n -(Meth) acrylate monomer having no ring structure such as butyl (meth) acrylate; unsaturated carboxylic acid such as (meth) acrylic acid, maleic acid and itaconic acid; p-hydroxystyrene, p-tert-butoxy Aromatic alkenyl compounds such as carbonylhydroxystyrene, 3,5-di-tert-butyl-4-hydroxystyrene, 3,5-dimethyl-4-hydroxystyrene, p- (2-hydroxy-iso-propyl) styrene It is done.

  Among these, in terms of solubility of the polymer (P) in an organic solvent, the formula (13-1) to the formula (13-9), the formula (13-13) to the formula (13-16), the formula ( 13-21) to Expression (13-24), Expression (13-30) to Expression (13-34), Expression (13-37) to Expression (13-43), Expression (13-56) to Expression (13) -59), formula (13-62), formula (13-63), formula (13-66) to formula (13-69), formula (13-72) and formula (13-76) to formula (13- 79) and the geometric isomers and optical isomers thereof are preferred.

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

Structural unit (D)

  The polymer (P) has a process margin such as a depth of focus of the resist composition, a water repellency with respect to an immersion liquid (for example, water) in the immersion lithography process, and an antireflection property of the thinned resist film. It is preferable that the structural unit (D) having a naphthalene skeleton is contained.

  The content of the structural unit (D) is preferably 3 mol% or more and more preferably 5 mol% or more with respect to all the structural units of the polymer (P) in terms of resist dry etching resistance and refractive index. Further, the content of the structural unit (D) is preferably 50 mol% or less, more preferably 40 mol% or less, with respect to all the structural units of the polymer (P) in terms of the sensitivity and resolution of the resist composition. 30 mol% or less is still more preferable.

  When the structural unit (D) has an acid leaving group or a hydrophilic group, it tends to have a process margin such as a better depth of focus of the resist composition.

  In the polymer (P) containing the structural unit (D), when the structural unit (D) has an acid leaving group (preferably, in formula (6) described later, Y is an acid leaving group. In some cases, the acid-eliminable group is eliminated by the action of an acid, so that it becomes soluble in alkali. Therefore, the exposed portion becomes alkali-soluble and the unexposed portion remains insoluble in alkali. Therefore, when the polymer (P) is used as a positive chemically amplified resist, a resist pattern is formed.

Further, when the structural unit (D) does not have an acid leaving group (preferably, when Y is —C (═O) —OH or —OH in formula (6) described later), the structural unit Since (D) itself is acidic, the structural unit (D) has improved affinity for alkali, and process margins such as resist line edge roughness and depth of focus are improved.
Therefore, the polymer (P) containing the structural unit (D) is suitable for resists, and particularly suitable for positive chemically amplified resists.

  As the structural unit (D), for example, a unit represented by the formula (6) is preferable in terms of a process margin such as a depth of focus required for the resist.

H1 in Formula (6) is 0 or 1. H1 is preferably 0 from the viewpoint of the resolution of the resist composition, and h1 is preferably 1 from the viewpoint of the defect of the resist composition and the sensitivity of the resist composition.
h2 represents an integer of 1 to 4. h2 is preferably 1 in terms of the resolution of the resist composition, and is preferably 2-4 in terms of the defect of the resist composition and the sensitivity of the resist composition.

g1 is 0 or 1, and g2 is an integer of 0-20.
Further, g2 is preferably 1 to 4 in terms of the resolution of the resist composition. g3 is 0 or 1. R ¹⁰ represents a hydrogen atom or a methyl group.
G ¹ represents any ^one of a single bond, —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 represents a single bond or a linear, branched, or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and the divalent hydrocarbon group has a substituent and / or a hetero atom. Also good.
L ¹ is a linear or branched divalent hydrocarbon group having 1 to 4 carbon atoms, — (CH ₂ CH ₂ O) _g21 — or — from the viewpoint of solubility of the polymer (P) in an organic solvent. _{(CH 2 CH (CH 3)} O) g22 - are preferred. Here, g21 and g22 each represent an integer of 1 to 5, and g21 and g22 are each preferably 1 or 2 in terms of resolution of the resist composition.
L ¹ is preferably at least one selected from the formulas (6-11) to (6-14) from the viewpoint of dry etching resistance of the resist.

In formulas (6-11) to (6-14), R ^{111 to} R ¹¹⁶ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
Z represents an atomic group constituting a cyclic hydrocarbon group in L ¹ .
Incidentally, in the formula (6-11) to (6-14), upper left to bonds are G ^1, bond the lower right to the oxygen atom or a naphthalene ring, respectively coupled.

Further, when G is —C (═O) —O—, L ¹ is —C (CH ₃ ) ₂ —, —C (CH ₃ ) ₂ —CH ₂ —, in terms of the sensitivity of the resist composition. At least one selected from —C (CH ₃ ) (CH ₂ CH ₃ ) —, formula (6-11) and formula (6-12) is preferred.
Also, in the case of h1 = 1, in terms of sensitivity of the resist composition, L 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 formulas (6-13) and (6-14) are more preferable.

R ¹¹ and R ¹² 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 a carboxy group esterified with an alcohol having 1 to 6 carbon atoms, or R ¹¹ and R ¹² and together -O -, - S -, - NH- or a methylene chain of chain length 1-6.
In the case of h1 = 1, R ¹¹ and R ¹² are each independently a hydrogen atom or a straight chain having 1 to 4 carbon atoms in terms of transparency to the excimer laser light of the polymer (P) and the resolution of the resist composition. Branched alkyl groups are preferred.

Y represents —C (═O) —OH, —OH or an acid leaving group.
Y is preferably —C (═O) —OH or —OH in terms of the defect and sensitivity of the resist composition and the line edge roughness of the resist, and in terms of the storage stability of the resist composition, ) To an acid leaving group represented by formula (6-5) is preferable.

In formulas (6-2) and (6-4), R ¹²¹ , R ¹²² and R ¹²³ and R ¹⁴¹ , R ¹⁴² and R ¹⁴³ are each independently (i) a monovalent monovalent group having 4 to 20 carbon atoms. Represents an alicyclic hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, and at least one of R ¹²¹ , R ¹²² and R ¹²³ and R ¹⁴¹ , R ¹⁴² and R ¹⁴³ is Or (ii) any two of R ¹²¹ , R ¹²² and R ¹²³ and R ¹⁴¹ , R ¹⁴² and R ¹⁴³ are bonded to each other, and each is bonded to each other. Together with the carbon atom forming a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and participating in bonding among R ¹²¹ , R ¹²² and R ¹²³ and R ¹⁴¹ , R ¹⁴² and R ¹⁴³ The other one that was not done is a linear or branched alkyl group having 1 to 4 carbon atoms or carbon It represents a monovalent alicyclic hydrocarbon group or a derivative thereof having 4 to 20.

In formulas (6-3) and (6-5), R ¹³³ and R ¹⁵³ are each independently (i) a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon number 1 R ¹³¹ , R ¹³² , R ¹⁵¹ and R ¹⁵² each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, or (Ii) R ¹³¹ and R ¹³³ or R ¹³² and R ¹³³ or R ¹⁵¹ and R ¹⁵³ or R ¹⁵² and R ¹⁵³ are bonded to each other, and together with the carbon atoms to which they are bonded, each has 4 to 20 carbon atoms The remaining one of R ¹³¹ , R ¹³² , R ¹⁵¹ and R ¹⁵² that forms a divalent alicyclic hydrocarbon group or a derivative thereof and does not participate in bonding represents a hydrogen atom.

G4 in the formula (6) is 0 or 1, and when Y is any one of the formulas (6-2) to (6-4), the polymer (P) may have transparency to excimer laser light. In view of the sensitivity of the resist composition, 1 is preferable. When Y is the formula (6-5), g4 is preferably 0 from the viewpoint of the transparency of the polymer (P) to excimer laser light and the sensitivity of the resist composition.
L ² represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, and the divalent hydrocarbon group may have a substituent and / or a hetero atom. Good. Here, as a substituent, —C (CF ₃ ) ₂ —OH, a hydroxy group, a cyano group, a carboxy group, an acyl group having 1 to 6 carbon atoms, and a carboxy group esterified with an alcohol having 1 to 6 carbon atoms. And amino groups and the like. Examples of the hetero atom include a sulfur atom, a nitrogen atom, and a phosphorus atom.
In addition, when g4 = 1, L ² is a linear or branched divalent hydrocarbon group having 1 to 4 carbon atoms in terms of solubility of the polymer (P) in an organic solvent, — (OCH ₂ CH _{2) g31} - or _{- (OCH 2 CH (CH 3} )) g32 - are preferred. Here, g31 and g32 each represent an integer of 1 to 5, and 1 or 2 is preferable in terms of the resolution of the resist composition.

X ¹⁰ is preferably a linear or branched alkyl group having 1 to 6 carbon atoms having a hydroxy group or a cyano group as a hydroxy group or a substituent, from the viewpoints of reducing defects in the resist composition and resist pattern rectangularity.
h11 is preferably 0 in terms of the resolution of the resist composition.
The structural unit (D) represented by the formula (6) is transparent in terms of transparency to light having a wavelength of 250 nm or less, such as excimer laser light (ArF excimer laser light, KrF excimer laser light, etc.) of the polymer (P). And those represented by formula (7-1) are preferred.

In formula (7-1), R ¹⁰ , R ¹¹ , R ¹² , G ¹ , L ¹ , L ² , X ¹⁰ , Y, h 1, h 11, g 1, g 2, g 3 and g 4 are the same as in formula (6), respectively. It is.

The structural unit (D) can be used alone or in combination of two or more.
The polymer (P) containing the structural unit (D) can be produced by polymerizing a monomer including the monomer (d) that gives the structural unit (D).

  Examples of the monomer (d) include monomers represented by the formulas (8-1) to (8-78). In formula (8-1) to formula (8-78), R represents a hydrogen atom or a methyl group.

Among these, in terms of the defect of the resist composition and the line edge roughness of the resist, the equations (8-1) to (8-30), the equations (8-38) to the equations (8-52) and ( Monomers represented by 8-60) to (8-70) and geometrical isomers and optical isomers thereof are preferable.
In terms of the sensitivity of the resist composition, the formula (8-11), the formula (8-12), the formula (8-15) to the formula (8-20), the formula (8-23) to the formula (8- 28), monomer represented by formula (8-46), formula (8-47), formula (8-49) to formula (8-52) and formula (8-69), and geometrical isomers thereof And optical isomers are preferred.
Further, from the viewpoint of the storage stability of the resist composition, the formula (8-31) to the formula (8-37), the formula (8-53) to the formula (8-59), and the formula (8-71) to the formula ( Monomers represented by 8-78) and geometrical isomers and optical isomers thereof are preferable.

Structural unit (E)

  The polymer (P) may contain other structural units (E) as necessary in addition to the structural units (A) to (D) described above.

Examples of the structural unit (E) include the structural unit (E1) having an alicyclic skeleton (nonpolar alicyclic skeleton) without having an acid-eliminable group and a hydrophilic group.
Here, the alicyclic skeleton is a skeleton having one or more cyclic saturated hydrocarbon groups.

The structural unit (E1) tends to exhibit the effect of developing the resist dry etching resistance.
The structural unit (E1) can be used alone or in combination of two or more.
As the structural unit (E1), structural units represented by formula (11-1) to formula (11-4) are preferable in terms of resistance to dry etching of a resist.

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

  p and p1 represent the integer of 0-2.

  In addition, n301, n302, n303, and n304 are preferably 0 from the viewpoint of resist dry etching resistance.

  p and p1 are preferably 0 in terms of solubility of the polymer (P) in an organic solvent, and 1 is preferably in terms of dry etching resistance of the resist.

  The polymer (P) containing the structural unit (E1) can be produced by polymerizing a monomer containing the monomer (e1) having a nonpolar alicyclic skeleton.

  Examples of the monomer (e1) include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentadienyl ( Examples include (meth) acrylates and derivatives having a linear or branched alkyl group having 1 to 6 carbon atoms on the alicyclic skeleton of these compounds.

Examples of the monomer (e1) include monomers represented by formulas (14-1) to (14-5). In formula (14-1) to formula (14-5), R represents a hydrogen atom or a methyl group.
In addition to the above monomers, those having a cycloolefin structure such as norbornene as the alicyclic skeleton can be mentioned.

The polymer (P) may further contain a structural unit (E2) other than the structural unit (E1) as the structural unit (E).
The polymer (P) containing the structural unit (E2) can be produced by polymerizing a monomer including the monomer (e2).

  Examples of the monomer (e2) include methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) ) Acrylate, isobutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoro-n-propyl (meth) acrylate 2,2,3,3,3-pentafluoro-n-propyl (meth) acrylate, methyl α- (tri) fluoromethyl acrylate, ethyl α- (tri) fluoromethyl acrylate, 2-ethylhexyl α- (tri) Fluoromethyl acrylate, n-propyl α- (tri) fluor (Meth) acrylate having a linear or branched structure such as methacrylate, iso-propyl α- (tri) fluoromethyl acrylate, n-butyl α- (tri) fluoromethyl acrylate, iso-butyl α- (tri) fluoromethyl acrylate Or α-fluorine-substituted (meth) acrylate; aromatic alkenyl compounds such as styrene, α-methylstyrene, vinyltoluene, p-tert-perfluorobutylstyrene; carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; Examples include ethylene, propylene, tetrafluoroethylene, acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, vinyl chloride, vinyl fluoride, vinylidene fluoride, and vinylpyrrolidone.

  As for content of a structural unit (E), 20 mol% or less is preferable with respect to all the structural units of a polymer (P).

Among the structural units (A) to (E) listed above, the polymer (P) is suitable for use as a resist, particularly as a positive chemically amplified resist. It is preferable to contain a structural unit (B).
Preferred combinations of the structural unit (A) and the structural unit (B) in the polymer (P) include those listed in Tables 1 to 4.

  The structural unit (A) is one or more selected from the group consisting of formula (10-1) and formula (10-3), formula (10-7) and formula in terms of the defect of the resist composition. One or more selected from the group consisting of (10-8), formula (10-10), formula (10-12), formula (10-17) and formula (10-19) can be used in combination.

  Furthermore, in terms of pattern rectangularity, the polymer (P) is represented by the formula (C) as a structural unit (C) in addition to the combinations of the structural unit (A) and the structural unit (B) listed in Tables 1 to 4. 13-1) One monomer selected from the group consisting of formula (13-26), formula (13-27), formula (13-30), formula (13-31) and formula (13-68) A combination having three types of structural units including the structural units obtained from (hereinafter referred to as “combination (1)”) is preferable.

Moreover, it is chosen from the group which consists of Formula (14-1) and Formula (14-3) as a structural unit (E1) to the combination or combination (1) enumerated in Table 1-Table 4 at the point of dry etching tolerance. A combination of one or more monomers is preferred.

Method for producing polymer (P)

  As a method for producing the polymer (P), known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. Among these, solution polymerization is preferable because a polymer having a relatively low molecular weight can be easily obtained.

  The solution polymerization may be batch polymerization or dropping polymerization, but dropping polymerization in which a monomer is dropped into a polymerization vessel is preferable. The monomer to be dropped may be either a monomer alone or a solution obtained by dissolving the monomer in an organic solvent.

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

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

As an organic solvent (hereinafter referred to as “polymerization solvent”) used in the dropping polymerization, a known solvent can be used. Specific examples of the polymerization solvent include chain ethers such as diethyl ether and propylene glycol monomethyl ether, and ethers such as tetrahydrofuran and cyclic ethers such as 1,4-dioxane; methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, Esters such as butyl lactate, propylene glycol monomethyl ether acetate and γ-butyrolactone; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Amides such as N, N-dimethylacetamide and N, N-dimethylformamide; Dimethyl sulfoxide and the like Sulphoxides; aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as hexane; hydrocarbons such as alicyclic hydrocarbons such as cyclohexane; and mixed solvents thereof.
Among these, a hydroxyl group-containing ester such as ethyl lactate is preferable when obtaining a low molecular weight polymer.
These solvents can be used alone or in combination of two or more.

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

  As the polymerization initiator, those that generate radicals efficiently by heat are preferable. As such a polymerization initiator (hereinafter referred to as “polymerization initiator A”), for example, 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 2,2 Azo compounds such as' -azobis [2- (2-imidazolin-2-yl) propane]; 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, di (4-tert-butylcyclohexyl) ) Organic peroxides such as peroxydicarbonate.

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

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

When the polymer (P) is used for lithography, a chain transfer agent (hereinafter referred to as “chain transfer agent A”) may be used as long as the storage stability of the resist composition is not hindered.
Examples of such chain transfer agent A include 1-butanethiol, 2-butanethiol, 1-octanethiol, 1-decanethiol, 1-tetradecanethiol, cyclohexanethiol, 2-methyl-1-propanethiol and 2 -Hydroxyethyl mercaptan.
When used for lithography applications using ArF excimer laser (wavelength: 193 nm), the chain transfer agent A does not have an aromatic ring so as not to reduce the light transmittance (transmittance for light with a wavelength of 193 nm) as much as possible. Is preferred.

The polymer solution produced by solution polymerization is diluted with a solvent for polymerization to an appropriate solution viscosity, if necessary, and then in a large amount of poor solvent (deposition solvent) such as methanol, water, hexane, heptane, etc. The polymer (P) can be precipitated by dropping.
The precipitation of the polymer (P) is very effective for removing unreacted monomers and polymerization initiators remaining in the polymer solution. If these unreacted substances remain as they are, there is a possibility of adversely affecting the resist performance. Therefore, it is preferable to remove the polymer (P) as much as possible when the polymer (P) is used for lithography.
The precipitate of the polymer (P) can be obtained as a powder of the polymer (P) by filtering and drying as necessary.
Further, after the precipitation, the solution can be separated by filtration, and subsequently redissolved in a solvent, and the redissolved solution is sequentially concentrated to obtain a polymer (P) solution.

Resist composition

The resist composition for immersion exposure according to the present invention contains a polymer (P).
A resist composition in which the polymer (P) is dissolved in a solvent can be used. Moreover, this polymer solution can also be used for preparation of a resist composition as it is, without isolate | separating a polymer from the polymer solution obtained by solution polymerization etc. Further, the polymer solution can be diluted with an appropriate solvent or concentrated to be used for preparing a resist composition.
Further, the polymer (P) solution is dropped into a poor solvent (deposition solvent) to precipitate the polymer (P), and the polymer obtained by filtration is filtered, and then the resist remains in a wet powder without drying. It can also be used for the preparation of the composition. Furthermore, after the polymer powder is dissolved in a suitable solvent, the concentrated polymer solution can be used for the preparation of a resist composition.

Examples of the solvent used in preparing the resist composition solution include linear or branched ketones such as methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, and 2-hexanone; cyclopentanone, cyclohexanone, and the like. Cyclic ketones; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol Propylene glycol monoalkyl ethers such as monomethyl ether and propylene glycol monoethyl ether; Ethylene glycol monoalkyl ethers such as coal monomethyl ether and ethylene glycol monoethyl 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 Alcohols such as butyl alcohol, cyclohexanol, 1-octanol; pentane, 2-methylbutane, n-hexane, 2-methylpentane, 2,2-dibutylbutane, 2,3-dibutylbutane, n-heptane, n- Fatty acids having 5 to 11 carbon atoms such as octane, isooctane, 2,2,3-trimethylpentane, n-nonane, 2,2,5-trimethylhexane, n-decane, n-dodecane, etc. Family hydrocarbon solvents; 1,4 dioxane, ethylene carbonate and γ- butyrolactone.
These solvents can be used alone or in combination of two or more.
Among these, propylene glycol monomethyl ether acetate, ethyl lactate, cyclohexanone and γ-butyrolactone are preferable from the viewpoint of safety.

The content of the polymer (P) in the resist composition is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less in terms of the viscosity of the resist composition. In addition, the content of the polymer (P) is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 8% by mass or more in terms of the resist film thickness.

Chemically amplified resist composition

When the resist composition for immersion exposure according to the present invention is a chemically amplified resist composition, the resist composition further contains a photoacid generator.

Photoacid generator

The photoacid generator can be arbitrarily selected from those that can be used as an acid generator of a chemically amplified resist composition.
Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, sulfone compounds, sulfonate ester compounds, quinonediazide compounds, and diazomethane compounds.
Of these, onium salt compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like are preferable.
Specific examples include triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, diphenyliodonium triflate, diphenyliodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate. , Diphenyliodonium hexafluoroantimonate, p-methylphenyldiphenylsulfonium nonafluorobutanesulfonate, and tri (tert-butylphenyl) sulfonium trifluoromethanesulfonate.

The photoacid generator can be used alone or in combination of two or more.
Although content of a photo-acid generator is suitably determined by the kind of photo-acid generator, 0.1 mass part or more is preferable with respect to 100 mass parts of polymers (P), and 0.5 mass part or more is more preferable. . By setting the content of the photoacid generator within this range, a chemical reaction due to the catalytic action of the acid generated by exposure can be sufficiently caused.
Moreover, 20 mass parts or less are preferable with respect to 100 mass parts of polymers (P), and, as for content of a photo-acid generator, 10 mass parts or less are more preferable. By making the content of the photoacid generator within this range, the stability of the resist composition is improved, and the occurrence of uneven coating during application of the resist composition and scum during development of the resist composition is reduced. .

  In addition to the polymer (P), the resist composition of the present invention contains a nitrogen-containing compound as a quencher as long as it does not affect the pattern shape, impair pattern transferability, or cause a decrease in throughput. May be. By containing the nitrogen-containing compound, the resist pattern shape, the stability over time, and the like are improved. That is, the cross-sectional shape of the resist pattern becomes closer to a rectangle, and when the resist film is exposed, post-exposure baked (PEB), and left for the next development process, the cross-sectional shape of the pattern is deteriorated. Is more suppressed.

As the nitrogen-containing compound, known compounds can be used, but amines are preferable, and secondary lower aliphatic amines and tertiary lower aliphatic amines are more preferable.
Here, the “lower aliphatic amine” refers to an alkyl or alkyl alcohol amine having 5 or less carbon atoms.
Examples of the secondary lower aliphatic amine and tertiary lower aliphatic amine include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tripentylamine, diethanolamine and triethanolamine. Can be mentioned. Of these, tertiary alkanolamines such as triethanolamine are more preferred.

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

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

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

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

  Furthermore, the resist composition of the present invention may contain various additives such as surfactants, other quenchers, sensitizers, antihalation agents, storage stabilizers, and antifoaming agents as necessary. it can. Any of these additives can be used as long as it is known in the art. Moreover, what is necessary is just to determine the compounding quantity of these additives suitably.

In the present invention, the substrate on which the pattern is formed is a state in which an immersion liquid is interposed between the step of forming the resist composition of the present invention on the substrate and the resist film and the final lens of the exposure apparatus. And a step of exposing with light having a wavelength of 250 nm or less and a step of developing the resist film with a developer.

substrate

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

Resist film

The resist film is obtained by applying a resist composition to the surface of a substrate by spin coating or the like and drying it by baking (pre-baking) or the like.
The thickness of the resist film is 0.05 to 1.0 μm.

Immersion liquid

Examples of the immersion liquid include, but are not limited to, pure water, perfluoro-2-butyltetrahydrofuran, perfluorotrialkylamine, perhydronaphthalene, and perhydropyrene.

exposure

The exposure (irradiation of radiation) is carried out through a photomask with an immersion liquid interposed between the resist film and the final lens of the exposure apparatus.
As the radiation used for exposure, light having a wavelength of 250 nm or less is used, and ultraviolet rays such as i-line and g-line, KrF excimer laser, ArF excimer laser or F ₂ excimer laser are preferable.
In the case of a resist composition for immersion exposure in semiconductor production, an ArF excimer laser is preferred.

developing

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

Method for manufacturing a substrate on which a pattern is formed

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

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

1. Evaluation of polymer <content of each constituent unit of polymer>
The content of the constituent units of the polymer, in the case where it can be determined by the ¹ H-NMR measurement was determined by ¹ H-NMR measurement. Further, when it could not be determined by ¹ H-NMR measurement due to proton peak overlap or the like, it was determined by ¹³ C-NMR measurement.
GX-270 type FT-NMR (trade name) manufactured by JEOL Ltd. was used for ¹ H-NMR measurement. About 5% of the polymer sample solution (deuterated chloroform solution or deuterated dimethyl sulfoxide solution) was put in a test tube having a diameter of 5 mmφ, and the measurement was carried out with an observation frequency of 400 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.
^{For 13} C-NMR measurement, UNITY-INOVA type FT-NMR (trade name) manufactured by Varian Technologies was used. About 20% by mass of a polymer sample in a deuterated dimethyl sulfoxide solution was put into a test tube having a diameter of 5 mmφ, and the proton complete decoupling method in which the measurement temperature was 60 ° C., the observation frequency was 125 MHz, and the nuclear overhauser effect (NOE) was removed. The measurement was carried out at a total of 50,000 times.

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

<Light transmittance>
10 parts of a resist polymer and 42 parts of propylene glycol monomethyl ether acetate (hereinafter referred to as “PGMEA”) as a solvent were mixed to obtain a uniform solution. This was filtered through a membrane filter having a pore size of 0.1 μm to prepare a polymer solution.
Next, the polymer solution was spin-coated on a quartz wafer as a substrate, and prebaked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 1.0 μm.
The resist film produced on the quartz wafer was installed on the sample side of the UV-3100 (trade name) made by Shimadzu Corporation, and the untreated quartz wafer was placed on the reference side. The light transmittance was measured. In the measurement, the wavelength range was 192 to 194 nm, the scan speed was medium, the sampling pitch was automatic, and the slit width was 2.0.

2. Evaluation of resist composition <Preparation of resist composition>
100 parts of the polymer in terms of solid content and 2.0 parts of triphenylsulfonium triflate as a photoacid generator were dissolved in PGMEA so that the polymer concentration was 10.0% to obtain a uniform solution. . Thereafter, this solution was filtered through a membrane filter having a pore size of 0.1 μm to prepare a resist composition.

<Creation of resist pattern>
The prepared resist composition was spin-coated on a silicon wafer and pre-baked at 120 ° C. for 60 seconds using a hot plate to produce a resist film having a thickness of 0.3 μm. Next, after exposure using an ArF excimer laser exposure machine (wavelength: 193 nm) using a 0.16 μm line-and-space pattern mask, post-exposure baking was performed at 120 ° C. for 60 seconds using a hot plate. . Thereafter, development was performed at room temperature using a 2.38% tetramethylammonium hydroxide aqueous solution, washed with pure water, and dried to form a resist pattern.

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

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

<Elution properties of quencher components in immersion liquid>
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. This resist film was immersed in 100 ml of pure water kept at room temperature for 5 minutes. The obtained resist film was exposed in the same manner as in the case of creating the resist pattern, and then post-exposure baking was performed at 120 ° C. for 60 seconds using a hot plate. Subsequently, development was performed at room temperature using a 2.38% tetramethylammonium hydroxide aqueous solution, washed with pure water, and dried to form a resist pattern.
In the above exposure, the exposure amount at which a 0.16 μm line and space pattern mask was transferred to a resist line width of 0.16 μm was measured as sensitivity E _wet (mJ / cm ² ) in immersion exposure.
The absolute value of E _dry -E _wet was expressed by E _diff , and used as an index of the elution property of the quencher component into the immersion liquid. A smaller value indicates that the quencher component is less likely to elute into the immersion liquid.

<Pattern cross-sectional shape of resist by immersion exposure>
JSM-6340F field emission scanning electron microscope (manufactured by JEOL Ltd.) with respect to the cross-sectional shape in the vertical direction of the resist pattern obtained during the evaluation of the dissolution property of the quencher component into the immersion liquid ( Product name), and the cross-sectional shape of the resist pattern by immersion exposure was evaluated according to the following criteria.
“Rectangle”: The cross-sectional shape is rectangular “Trap”: The cross-sectional shape is trapezoidal “T-top”: The cross-sectional shape is T-shaped

[Example 1]
66.0 parts of ethyl lactate was added to a flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer at room temperature, and then nitrogen was blown into the ethyl lactate for 30 minutes using a ball filter. Thereafter, the temperature in the flask was raised to 80 ° C. while stirring in a nitrogen atmosphere.
Then, 27.2 parts of α-methacryloyloxy-γ-butyrolactone (hereinafter referred to as “GBLMA”) represented by the formula (51), 2-methacryloyloxy-2-methyladamantane (hereinafter referred to as the formula (52)) 37.4 parts) (referred to as “MAdMA”), a mixture comprising 55% by mass of 2-cyano-5-norbornyl methacrylate and 45% by mass of 3-cyano-5-norbornyl methacrylate represented by the formula (53) (Hereinafter referred to as “CNNMA”) 8.2 parts, dimethylaminoethyl methacrylate (hereinafter referred to as “DMAEMA”) 6.3 parts represented by formula (54), ethyl lactate 118.7 parts and dimethyl-2,2 A monomer solution in which 9.20 parts of '-azobisisobutyrate (DAIB) was mixed was prepared. This monomer solution was put into a dropping device and dropped into the flask at a constant rate over 4 hours. After completion of dropping, the mixture was kept at an internal temperature of 80 ° C. for 3 hours to obtain a polymer (A-1) solution.

  Subsequently, a polymer (A-1) solution was dripped in about 10 times amount of methanol of the stirring state which is a precipitation solvent, and the white deposit was obtained. After this precipitate was filtered off, it was again poured into about 10 times the amount of methanol, and the precipitate was washed with stirring. Thereafter, the precipitate was filtered off and dried under reduced pressure at 60 ° C. for about 40 hours. The obtained polymer (A-1) was evaluated, and the results are shown in Table 5.

[Example 2]
The initial charged ethyl lactate in the flask was 75.6 parts, and the monomer solution in the dropping apparatus was 2-exo-acryloyloxy-4-oxatricyclo [4.2.1. 0 ^3,7 ] nonan-5-one (hereinafter referred to as “NLA”) 29.1 parts, 2-methacryloyloxy-2-ethyladamantane (hereinafter referred to as “EAdMA”) represented by the formula (56) 39. 7 parts, 13.1 parts of 1-acryloyloxy-3-hydroxyadamantane (hereinafter referred to as “HAdA”) represented by the formula (57), tricyclodecanyl methacrylate (hereinafter, “ 8.8 parts) (referred to as “TCDMA”), 0.1 part of DMAEMA, 136.1 parts of ethyl lactate, and 1.48 parts of DAIB. Other conditions were the same as in Example 1 to obtain a polymer (A-2) solution.

  Subsequently, the precipitation solvent was changed to methanol / water = 90/10 (volume% ratio), and other conditions were precipitated, filtered and dried in the same manner as in Example 1 to obtain a polymer (A-2). . The obtained polymer (A-2) was evaluated, and the results are shown in Table 5.

[Example 3]
8-acryloyloxy represented by the formula (59) using ethyl lactate, which is an initial charging solvent in the flask, as a mixed solvent of 64.5 parts of PGMEA and 16.1 parts of γ-butyrolactone. -4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one 50% by mass and 9-acryloyloxy-4-oxatricyclo [5.2.1.0 ^2,6 ] decane 26.6 parts of a mixture consisting of 50% by mass of 3-one (hereinafter referred to as “OTDA”), 2-methacryloyloxy-2-cyanomethyladamantane (hereinafter referred to as “CMMAMA”) 20 represented by the formula (60) 20 0.7 part, diethylaminoethyl methacrylate represented by the formula (61) (hereinafter referred to as “DEAEMA”) 0.7 part, EAdMA 48.6 parts, PGMEA 116.0 parts, γ-butyrolactone 2 It was mixed .0 parts and DAIB5.06 parts and a monomer solution. Other conditions were the same as in Example 1 to obtain a polymer (A-3) solution.

  Next, precipitation, filtration and drying were conducted in the same manner as in Example 2 to obtain a polymer (A-3). The obtained polymer (A-3) was evaluated, and the results are shown in Table 5.

[Example 4]
18. Initially charged ethyl lactate in the flask is 68.5 parts, and the monomer solution in the dropping apparatus is 1-methacryloyloxy-3-hydroxyadamantane (hereinafter referred to as “HAdMA”) represented by the formula (62). A monomer solution was prepared by mixing 8 parts, 30.6 parts of GBLMA, 32.8 parts of MAdMA, 0.1 part of DMAEMA, 123.3 parts of ethyl lactate, and 3.50 parts of DAIB. Other conditions were the same as in Example 1, and a polymer (A-4) solution was obtained.

  Then, precipitation, filtration and drying were conducted in the same manner as in Example 2 to obtain a polymer (A-4). The obtained polymer (A-4) was evaluated, and the results are shown in Table 5.

[Example 5]
The initial charged ethyl lactate in the flask was 70.1 parts of PGMEA, and the monomer solution in the dropping apparatus was 1- (1-methacryloyloxy-1-methylethyl) adamantane (hereinafter referred to as “IAdMA” represented by the formula (63)). 31.4 parts, GBLMA 34.0 parts, HAdMA 18.4 parts, DMAEMA 0.3 parts, PGMEA 126.2 parts and DAIB 14.72 parts. Other conditions were the same as in Example 1 to obtain a polymer (A-5) solution.

  Next, precipitation, filtration and drying were conducted in the same manner as in Example 2 to obtain a polymer (A-5). The obtained polymer (A-5) was evaluated, and the results are shown in Table 5.

[Comparative Example 1]
The initial charged ethyl lactate in the flask was 69.6 parts of PGMEA, and the monomer solution in the dropping apparatus was mixed with 27.2 parts of GBLMA, 37.4 parts of MAdMA, 18.9 parts of HAdMA, 125.3 parts of PGMEA and 7.36 parts of DAIB. A monomer solution was obtained. Other conditions were the same as in Example 1 to obtain a polymer (B-1) solution.

  Then, precipitation, filtration and drying were conducted in the same manner as in Example 2 to obtain a polymer (B-1). The obtained polymer (B-1) was evaluated, and the results are shown in Table 5.

[Comparative Example 2]
The initial charged ethyl lactate in the flask was 66.9 parts of PGMEA, and the monomer solution in the dropping apparatus was 15.6 parts of a monomer having an aminodiketone structure represented by the formula (64) (hereinafter referred to as “ADKMA”). A monomer solution was prepared by mixing 27.2 parts of GBLMA, 37.4 parts of MAdMA, 120.4 parts of PGMEA, and 0.66 parts of DAIB. Other conditions were the same as in Example 1 to obtain a polymer (C-1) solution.

  Then, precipitation, filtration and drying were conducted in the same manner as in Example 2 to obtain a polymer (C-1). The obtained polymer (C-1) was evaluated, and the results are shown in Table 5.

  The polymers of Examples 1 to 5 and Comparative Example 1 had excellent light transmittance. However, the polymer of Comparative Example 2 had a low light transmittance.

[Examples 6 to 10 and Comparative Example 3]
Resist compositions (a) to (f) were prepared using the polymers shown in Table 6. Next, resist patterns (a) to (f) were used to create resist patterns. The resist compositions (a) to (f) were evaluated, and the results are shown in Table 6.

[Comparative Example 4]
100 parts of the polymer (B-1) in terms of solid content, 2.0 parts of triphenylsulfonium triflate as a photoacid generator and 0.05 part of trioctanolamine as a quencher, with a polymer concentration of 10 parts. It was dissolved in PGMEA so as to be 0.0% to obtain a uniform solution. Thereafter, this solution was filtered through a membrane filter having a pore diameter of 0.1 μm to prepare a resist composition (g). Next, a resist pattern was prepared using the resist composition (g). Evaluation of the resist composition (g) was carried out, and the results are shown in Table 6.

  As is apparent from Table 6, the resist compositions of Examples 6 to 10 had sufficient sensitivity and resolution, and the elution of the quencher component into the immersion liquid was small, and the pattern cross-sectional shape was rectangular. It was. In contrast, the resist composition of Comparative Example 3 has a low sensitivity, and the resist composition of Comparative Example 4 has a good polymer light transmittance, but the quencher component is eluted into the immersion liquid. In many cases, the pattern cross-sectional shape of the resist was T-top.

Claims (4)

A resist polymer containing a structural unit (M) having an amine skeleton represented by the following formula (1).

(In the formula (1), R ¹⁰ represents a hydrogen atom or a methyl group. G represents a single bond, —C (═O) —O—, —O— or —O—C (═O) —. L represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms, which may have a substituent and / or a hetero atom. The divalent hydrocarbon group may contain either —C (═O) —O— or —O—C (═O) —, wherein R ¹¹ and R ¹² are independent of each other. Represents a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms, and this monovalent hydrocarbon group may have a substituent and / or a hetero atom. Furthermore, L and R ¹¹ , L and R ¹² , or R ¹¹ and R ¹² are combined to form a cyclic methylene chain having a chain length of 1 to 6 (— (CH ₂ ) _k — (k is 1 to 6). Integer And this cyclic methylene chain may have a substituent and / or a heteroatom.)   A resist composition for immersion exposure, comprising the polymer according to claim 1.   A chemically amplified resist composition for immersion exposure, comprising the polymer according to claim 1 and a photoacid generator.   A step of applying a resist composition according to claim 2 on a substrate to form a resist film, a wavelength of 250 nm or less with an immersion liquid interposed between the resist film and the final lens of the exposure apparatus The manufacturing method of the board | substrate with which the pattern which has the process exposed with the light and the process developed with a developing solution was formed.