JP5750227B2 - Chemically amplified photoresist composition and pattern forming method - Google Patents

Description

  The present invention relates to a chemically amplified photoresist composition and a pattern forming method, and more particularly, to chemical amplification used in semiconductor microfabrication, manufacturing of circuit boards such as liquid crystals and thermal heads, and other photofabrication processes. The present invention relates to a type photoresist composition and a pattern forming method using the same.

  In Patent Document 1, 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate and α-methacryloyloxy-γ-butyrolactone are charged at a molar ratio of 50:25:25 and polymerized. A chemical amplification type comprising: a resin comprising: an acid generator comprising triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate; a quencher comprising 2,6-diisopropylaniline; and a solvent. A photoresist composition is described.

JP 2006-257078 A

  In the case of a conventional chemically amplified photoresist composition, the resolution, line edge roughness, and exposure margin of the obtained pattern may not always be satisfactory.

The present invention includes the following inventions.
[1] An acid generator, a resin (A1) and a resin (A2) are contained,
Resin (A1) is a resin obtained by polymerizing (a1), (a2) and (a3),
Resin (A2) is a resin obtained by polymerizing (a1), (a2) and (a3),
The weight average molecular weight of the resin (A1) is smaller than the weight average molecular weight of the resin (A2),
A chemically amplified photoresist composition that satisfies the formulas (1), (2), and (3).
(A1): Acrylic monomer having a C ₆ -C ₂₀ saturated cyclic hydrocarbon group that becomes alkali-soluble by the action of an acid (a2): Acrylic monomer having an adamantyl group substituted with a hydroxyl group (a3): Lactone ring Acrylic monomer having 0.995 <S ¹ / T ¹ <1.005 (1)
0.995 <S ² / T ² <1.005 (2)
0.995 <S ³ / T ³ <1.005 (3)
S ¹ : In resin (A1), the charged amount (mol) of (a1) when the total amount of charged monomer of resin (A1) is 100 mol
S ² : Charge amount (mol) of (a2) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
S ³ : In resin (A1), the charged amount (mol) of (a3) when the total amount of charged monomer of resin (A1) is 100 mol
T ¹ : In resin (A2), charged amount (mol) of (a1) when the total amount of charged monomer of resin (A2) is 100 mol
T ² : In the resin (A2), the charged amount (mol) of (a2) when the total charged monomer amount of the resin (A2) is 100 mol
T ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A2) is 100 mol in resin (A2)

[2] The chemically amplified photoresist composition according to [1], wherein S ¹ / T ¹ , S ² / T ² and S ³ / T ³ are 1.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表し、^＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、Ｃ₁〜Ｃ_８脂肪族炭化水素基又はＣ_３〜Ｃ_１０飽和環状炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。］ [3] The chemically amplified photoresist composition according to [1] or [2], wherein (a1) is a monomer represented by formula (a1-1) or a monomer represented by formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and ^* represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10. ]

[4] The monomer represented by the formula (a1-1) is 2-methyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl The chemically amplified photoresist composition according to [3], which is methacrylate, 2-isopropyl-2-adamantyl acrylate or 2-isopropyl-2-adamantyl methacrylate.

[5] The chemically amplified photoresist composition according to [3], wherein the monomer represented by the formula (a1-2) is 1-ethyl-1-cyclohexyl acrylate or 1-ethyl-1-cyclohexyl methacrylate.

[6] (a2) is 3-hydroxy-1-adamantyl acrylate, 3-hydroxy-1-adamantyl methacrylate, 3,5-dihydroxy-1-adamantyl acrylate or 3,5-dihydroxy-1-adamantyl methacrylate [ The chemically amplified photoresist composition according to any one of 1] to [5].

[7] The chemically amplified photoresist composition according to any one of [1] to [6], wherein (a2) is 3,5-dihydroxy-1-adamantyl acrylate or 3,5-dihydroxy-1-adamantyl methacrylate. .

［式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表し、ｋ３は１〜７の整数を表し、^＊は−ＣＯ−との結合手を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、Ｃ₁〜Ｃ_４脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又はＣ₁〜Ｃ_４脂肪族炭化水素基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１、ｑ１又はｒ１が２以上のとき、それぞれ、複数のＲ^a21、Ｒ^a22又はＲ^a23は、互いに同一でも異なってもよい。］ [8] (a3) is a monomer represented by the formula (a3-1), a monomer represented by the formula (a3-2), or a monomer represented by the formula (a3-3) [1] to [ [7] The composition according to any one of [7].

[In Formula (a3-1)-Formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or ^* —O— (CH ₂ ) _k3 —CO—O—, k3 represents an integer of 1 to 7, and ^* represents a bond to —CO—. Represents a hand.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents a C _{1 to} C ₄ aliphatic hydrocarbon group.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or a C ₁ -C ₄ aliphatic hydrocarbon group.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 may be the same as or different from each other. ]

[9] The chemically amplified photoresist composition according to any one of [1] to [8], wherein the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is 1,000 or more.

[10] The composition according to any one of [1] to [8], wherein the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is 3,000 or more.

[11] The difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is less than 1,000, and the difference between the degree of dispersion of the resin (A1) and the degree of dispersion of the resin (A1) is The chemically amplified photoresist composition according to any one of [1] to [8], which is 0.1 or more.

［式（Ｂ１）中、Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記２価の飽和炭化水素基の−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよいＣ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］ [12] The chemically amplified photoresist composition according to any one of [1] to [11], wherein the acid generator is an acid generator represented by the formula (B1).

[In Formula (B1), Q ¹ and Q ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — of the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. .
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

[13] The chemically amplified photoresist composition according to [12], containing an acid generator in which Z ⁺ is an arylsulfonium cation.

[14] The chemically amplified photoresist composition according to [12] or [13], wherein Y ¹ is a group having an adamantane group or an oxo-adamantane group.

[15] The chemically amplified photoresist composition according to any one of [1] to [13], wherein the content of the acid generator is 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the resin.

[16] The chemically amplified photoresist composition according to any one of [1] to [15], further comprising a nitrogen-containing basic compound.

[17] The chemically amplified photoresist composition according to [16], wherein the nitrogen-containing basic compound is diisopropylaniline.

[18] A step of applying the chemically amplified photoresist composition according to any one of [1] to [17] on a substrate,
Removing the solvent from the composition after coating to form a composition layer;
Exposing the composition layer using an exposure machine;
Heating the composition layer after exposure,
The pattern formation method characterized by including the process of developing the composition layer after a heating using a image development apparatus.

  According to the chemically amplified photoresist composition of the present invention, a pattern having excellent resolution, line edge roughness, and exposure margin can be formed.

The chemically amplified photoresist composition of the present invention (hereinafter sometimes simply referred to as “resist composition”) includes an acid generator, a resin (A1), and a resin (A2).
In the present specification, unless otherwise specified, the examples of each substituent are applied to any chemical structural formula having the same substituent while appropriately selecting the number of carbon atoms. Those which can take any of linear, branched or cyclic are included unless otherwise specified, and in the same group, linear, branched and / or cyclic partial structures are mixed. It may be. When stereoisomers exist, all of those stereoisomers are included.

<resin>
Resin (A1) is a resin obtained by polymerizing (a1), (a2) and (a3),
Resin (A2) is a resin obtained by polymerizing (a1), (a2) and (a3),
The weight average molecular weight of the resin (A1) is smaller than the weight average molecular weight of the resin (A2),
Expressions (1), (2), and (3) are satisfied.
(A1): Acrylic monomer having a C ₆ -C ₂₀ saturated cyclic hydrocarbon group that becomes alkali-soluble by the action of an acid (a2): Acrylic monomer having an adamantyl group substituted with a hydroxyl group (a3): Lactone ring Acrylic monomer having 0.995 <S ¹ / T ¹ <1.005 (1)
0.995 <S ² / T ² <1.005 (2)
0.995 <S ³ / T ³ <1.005 (3)
S ¹ : In resin (A1), the charged amount (mol) of (a1) when the total amount of charged monomer of resin (A1) is 100 mol
S ² : Charge amount (mol) of (a2) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
S ³ : In resin (A1), the charged amount (mol) of (a3) when the total amount of charged monomer of resin (A1) is 100 mol
T ¹ : In resin (A2), charged amount (mol) of (a1) when the total amount of charged monomer of resin (A2) is 100 mol
T ² : In the resin (A2), the charged amount (mol) of (a2) when the total charged monomer amount of the resin (A2) is 100 mol
T ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A2) is 100 mol in resin (A2)
Preferably S ¹ / T ¹ = 1, S ² / T ² = 1 and / or S ³ / T ³ = 1, all of S ¹ / T ¹ , S ² / T ² and S ³ / T ³ Is more preferably 1.

  The resin of the present invention can be synthesized according to a method known in the art and a known method. The weight average molecular weight of the resin can be adjusted by changing the synthesis conditions, for example, the reaction time and the reaction temperature, in the synthesis of the resin.

ここで、芳香族炭化水素基としては、フェニル基、ナフチル基、アントラニル基、ｐ−メチルフェニル基、ｐ−ｔｅｒｔ−ブチルフェニル基、ｐ−アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、アントリル基、フェナントリル基、２，６−ジエチルフェニル基、２−メチル−６−エチルフェニル等のアリール基等が挙げられる。 The saturated cyclic hydrocarbon group may be monocyclic or polycyclic, for example, a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, A monocyclic saturated cyclic hydrocarbon group such as a cyclooctyl group; a group obtained by hydrogenating a condensed aromatic hydrocarbon group (for example, a hydronaphthyl group), a bridged cyclic hydrocarbon group (for example, an adamantyl group, Norbornyl group, methylnorbornyl group) and the like. Further, a group in which a bridging ring (for example, norbornane ring) and a single ring (for example, cycloheptane ring, cyclohexane ring) or polycyclic (for example, decahydronaphthalene ring) or a bridging ring are condensed as described below. Groups; groups in which these are combined (methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group) and the like.

Here, as the aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group Groups, biphenyl groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

  Examples of (a1) include a monomer represented by formula (a1-1) or a monomer represented by formula (a1-2).

式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表し、ｋ１は１〜７の整数を表す。但しＬ^a1及びＬ^a2で列挙した−Ｏ−等は、それぞれ、左側で式（ａ１−１）及び式（ａ１−２）の−ＣＯ−と結合し、右側でアダマンチル基又はシクロへキシル基と結合することを意味する。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、Ｃ₁〜Ｃ₈脂肪族炭化水素基又はＣ₃〜Ｃ₁₀飽和環状炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。

In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or —O— (CH ₂ ) _k1 —CO—O—, and k1 represents an integer of 1 to 7. However, —O— and the like enumerated for L ^a1 and L ^a2 are respectively bonded to —CO— of the formula (a1-1) and the formula (a1-2) on the left side, and to an adamantyl group or cyclohexyl group on the right side. Means to join.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.

  Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, 1-methylethyl group (isopropyl group), n-butyl group, 1,1-dimethylethyl group (tert-butyl group), 2,2-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-pentyl group, 1-methylbutyl Group, 2-methylbutyl group, 3-methylbutyl group, n-hexyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl Group, nonyl group, decyl group, undecyl group, alkyl group such as dodecyl group, and the like.

In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 are preferably, -O- or _{-O- (CH 2) f1 -CO-} O- and is (wherein f1 is 1 to 4), and more preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group for R ^a6 and R ^a7 is preferably C ₆ or less. Saturated cyclic hydrocarbon group is preferably C ₈ or less, more preferably C ₆ or less.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
k1 is preferably an integer of 1 to 4, more preferably 1.

  As a monomer (a1-1) which has an adamantyl group, the following are mentioned, for example. Among them, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate and 2-isopropyl-2-adamantyl (meth) acrylate are preferable, and those in the form of methacrylate are more preferable.

  As a monomer (a1-2) which has a cyclohexyl group, the following are mentioned, for example. Among these, 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl methacrylate is more preferable.

  The content of the structural unit derived from (a1) in the resin is usually from 10 to 95 mol%, preferably from 15 to 90 mol%, more preferably from 20 to 85 mol%, in all units of the resin. .

  (A2) Examples of the acrylic monomer having an adamantyl group substituted with a hydroxyl group (excluding the —OH group of the carboxyl group) include a monomer represented by the formula (a2-1).

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。

In formula (a2-1),
L ^a3 represents —O— or —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

  As an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the following are mentioned, for example. Among them, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl (meth) acrylate are Preferably, 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are more preferable, 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate Is more preferable.

  The content of the structural unit derived from the formula (a2) in the resin is usually from 3 to 40 mol%, preferably from 5 to 35 mol%, more preferably from 5 to 30 mol% in all the units of the resin. is there.

  Examples of the (a3) lactone ring-containing acrylic monomer include a monomer represented by the formula (a3-1), a monomer represented by the formula (a3-2), or a monomer represented by the formula (a3-3). .

式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表す。
ｋ３は１〜７の整数を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、Ｃ₁〜Ｃ₄脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又はＣ₁〜Ｃ₄脂肪族炭化水素基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１、ｑ１又はｒ１が２以上のとき、それぞれ、複数のＲ^a21、Ｒ^a22又はＲ^a23は、互いに同一でも異なってもよい。

In formula (a3-1) to formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or —O— (CH ₂ ) _k3 —CO—O—.
k3 represents an integer of 1 to 7.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents a C _{1 to} C ₄ aliphatic hydrocarbon group.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or a C ₁ -C ₄ aliphatic hydrocarbon group.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 may be the same as or different from each other.

In the formula (a3-1) to the formula (a3-3), examples of L ^{a4 to} L ^a6 include those described for L ^a3 .
L ^{a4 to} L ^a6 are each independently preferably —O—, —O— (CH ₂ ) _d1 —CO—O— (wherein d1 is an integer of 1 to 4), more preferably -O-. However, —O— and the like enumerated in L ^{a4 to} L ^a6 mean that they are bonded to —CO— of the formula (a3-1) to the formula (a3-3) on the left side and to the lactone ring on the right side. To do.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

  Examples of the acid stable monomer (a3-1) having a γ-butyrolactone ring include the following.

  As the acid stable monomer (a3-1) having a γ-butyrolactone ring, an acid labile monomer can also be exemplified. For example, the following are mentioned.

  Examples of the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

  As the monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring, an acid labile monomer can be exemplified. For example, the following are mentioned.

  Examples of the monomer (a3-3) having a condensed ring of a γ-butyrolactone ring and a cyclohexane ring include the following.

Among (a3), (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, (meth) acrylic acid tetrahydro-2-oxo- 3-furyl, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylic acid is preferred, in the form of methacrylate Is more preferable.

  The content of the structural unit derived from (a3) in the resin is usually 5 to 50 mol%, preferably 10 to 45 mol%, more preferably 15 to 40 mol% in all the units of the resin. .

The resin (A1) and the resin (A2) have structural units derived from (a1) to (a3), and (a1) to (a3) may be used alone or in combination of two or more. .
Moreover, you may have 1 type, or 2 or more types of structural units derived | led-out from the monomer different from (a1)-(a3). Examples of the monomer different from (a1) to (a3) include known monomers.

S ¹ / T ¹ , S ² / T ² and S ³ / T ³ are each preferably greater than 0.995 and less than 1.005, preferably greater than 0.997 and less than 1.003. More preferably, it is greater than 999 and less than 1.001, more preferably 1.
The difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is preferably 1,000 or more, and more preferably 3,000 or more. By adopting the above configuration, the chemically amplified photoresist composition containing these resins exhibits excellent resolution, good line edge roughness, and excellent exposure margin even in the formation of a fine pattern.

The weight average molecular weight of the resin (A1) and the resin (A2) is preferably 1,000 or more and 100,000 or less, more preferably 2,000 or more and 50,000 or less, and further preferably 2,500 or more and 30. , 000 or less.
The weight average molecular weight of any one of the resin (A1) and the resin (A2) is preferably 5,000 or less, more preferably 4,500 or less, and particularly preferably 4,000 or less.
When a resin having a weight average molecular weight of 5,000 or less is used, the amount used is preferably 40% or less, more preferably 35% or less, still more preferably 30% or less, based on the total amount of the resin. .
In addition, a weight average molecular weight is the value measured by GPC method, for example, Specifically, what was measured on the measurement conditions described in the Example, etc. are mentioned.

When the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is less than 1,000, the difference between the degree of dispersion of the resin (A1) and the degree of dispersion of the resin (A1) is 0.1 or more. Preferably, it is 0.2 or more.
Here, the degree of dispersion means weight average molecular weight Mw / number average molecular weight Mn. The number average molecular weight can be measured in terms of polystyrene by RI or UV detection.

<Acid generator (hereinafter sometimes referred to as "acid generator (B)")>
The acid generator (B) is classified into a nonionic type and an ionic type. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, DNQ 4 -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include not only acid generators (particularly photoacid generators) used in the resist field, but also photoinitiators for photocationic polymerization, photodecolorants for dyes, and photochromic agents. Known compounds that generate an acid by radiation (light) and mixtures thereof can also be used as appropriate. For example, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, Acid by radiation as described in JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. Can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよいＣ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. It is done.
In formula (B1), Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group include a linear alkylene group, a branched alkylene group, a monocyclic or polycyclic saturated cyclic hydrocarbon group, and a combination of two or more of these groups But you can.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkylene groups such as 17-diyl group, methylidene group, ethylidene group, propylidene group, 2-propylidene group;
A straight-chain alkylene, an alkyl group (in particular, C ₁ -C ₄ alkyl group, e.g., methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec- butyl group, tert- butyl group, etc.) the side chain of For example, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group Branched alkylene such as 2-methyl-1,4-butylene group;
Monocyclic saturated cyclic hydrocarbon groups which are cycloalkylene groups such as 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5-cyclooctylene group;
Examples thereof include polycyclic saturated cyclic hydrocarbon groups such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group and the like.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formula (b1-1) to formula (b1-6). L ^b1 is preferably any one of formulas (b1-1) to (b1-4), more preferably formula (b1-1) or formula (b1-2). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又はＣ₁〜Ｃ₁₅アルキレン基を表す。
Ｌ^b3は、単結合又はＣ₁〜Ｃ₁₂アルキレン基を表す。
Ｌ^b4は、Ｃ₁〜Ｃ₁₃アルキレン基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、Ｃ₁〜Ｃ₁₅アルキレン基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、Ｃ₁〜Ｃ₁₅アルキレン基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、Ｃ₁〜Ｃ₁₄アルキレン基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、Ｃ₁〜Ｃ₁₁アルキレン基を表す。但しＬ^ｂ９及びＬ^ｂ１０の炭素数上限は１２である。
中でも、式（ｂ１−１）で表される２価の基が好ましく、Ｌ^b2が単結合又は−ＣＨ_２−である式（ｂ１−１）で表される２価の基がより好ましい。

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C _{1 to} C ₁₅ alkylene group.
L ^b3 represents a single bond or a C _{1 to} C ₁₂ alkylene group.
L ^b4 represents a C _{1 to} C ₁₃ alkylene group. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a C _{1 to} C ₁₅ alkylene group.
L ^b6 and L ^b7 each independently represent a C _{1 to} C ₁₅ alkylene group. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a C _{1 to} C ₁₄ alkylene group.
L ^b9 and L ^b10 each independently represent a C _{1 to} C ₁₁ alkylene group. However, the upper limit of the carbon number of L ^b9 and L ^b10 is 12.
Among these, a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is more preferable.

Examples of the divalent group represented by the formula (b1-1) include the following.

Examples of the divalent group represented by the formula (b1-2) include the following.

Examples of the divalent group represented by the formula (b1-3) include the following.

Examples of the divalent group represented by the formula (b1-4) include the following.

Examples of the divalent group represented by the formula (b1-5) include the following.

Examples of the divalent group represented by the formula (b1-6) include the following.

The saturated hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, a C _{6 to} C ₁₈ aromatic hydrocarbon group, a C _{7 to} C ₂₁ aralkyl group, a C _{2 to} C ₄ acyl group, and a glycidyloxy group. .
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group, and the like.
Examples of the acyl group include acetyl, propionyl, butyryl and the like.

Examples of the aliphatic hydrocarbon group of Y, C ₁ ~C ₆ alkyl group is preferable.
Examples of the substituent of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group include a halogen atom (excluding a fluorine atom), a hydroxy group, an oxo group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group, and a hydroxy group-containing C. ₁ -C ₁₂ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic hydrocarbon group, C ₁ -C ₁₂ alkoxy groups, C ₆ -C ₁₈ aromatic hydrocarbon group, C ₇ -C ₂₁ aralkyl group, C ₂ -C ₄ acyl group, glycidyloxy group, or _{- (CH 2) j2 -O-} CO-R b1 group (wherein, R ^b1 is, C ₁ -C ₁₆ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic Represents a hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, j2 represents an integer of 0 to 4, and the like. The aliphatic hydrocarbon group, saturated cyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.
Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. .

Examples of the group in which —CH ₂ — in the aliphatic hydrocarbon group and saturated cyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include, for example, an ether structure or a cyclic ether structure (—CH ₂ -Is a group in which -O- is substituted), a saturated cyclic hydrocarbon group having an oxo group (a group in which -CH ₂ -is replaced by -CO-), and a sultone ring group (two adjacent -CH _2- groups are , —O— or —SO ₂ —) or a lactone ring group (groups in which two adjacent —CH ₂ — are replaced by —O— or —CO—, respectively).

In particular, examples of the saturated cyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y26).

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of Y that is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group include the following.

Examples of Y that is a saturated cyclic hydrocarbon group in which a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group is substituted include the following.

Examples of Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, include the following.

Examples of Y that is a saturated cyclic hydrocarbon group in which the — (CH ₂ ) _j2 —O—CO—R ^b1 group is substituted include the following.

  Y is preferably an adamantyl group which may have a substituent (for example, an oxo group or the like), more preferably an adamantyl group or an oxoadamantyl group.

Examples of the sulfonate anion in the salt represented by the formula (B1) include, for example, the following formulas (b1-1-1) to (b1-1-1-) in which the substituent L ^b1 is the formula (b1-1). The anion represented by 9) is preferred. In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent a C _{1 to} C ₄ aliphatic hydrocarbon group (preferably a methyl group).

Saturated cyclic substituted with a sulfonate anion or an aliphatic hydrocarbon group containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (b1-1) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-1) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (b1-1), For example, the following are mentioned.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-1) include the following: Things.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group or an aralkyl group and a divalent group represented by the formula (b1-1) include the following. It is done.

Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-1) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon having an oxo group and a divalent group represented by the formula (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (b1-1) include the following.

Saturated cyclic substituted with a sulfonate anion or an aliphatic hydrocarbon group containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (b1-2) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-2) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (b1-2), For example, the following are mentioned.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-2) include the following: Things.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, and a divalent group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-2) include the following.

Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (b1-2) include the following.

  Y which is an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group substituted with a sulfonate anion or an aliphatic hydrocarbon group containing an unsubstituted Y and a divalent group represented by the formula (b1-3) Examples of the sulfonate anion containing the divalent group represented by the formula (b1-3) include the following.

  Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an alkoxy group, and a divalent group represented by the formula (b1-3) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-3) include the following: Things.

Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-3) include the following.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group, and a divalent group represented by the formula (b1-4) include the following.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an alkoxy group and a divalent group represented by the formula (b1-4) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (b1-4) include the following: Things.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group having an oxo group and a divalent group represented by the formula (b1-4) include the following.

Among these, the following sulfonate anions having a divalent group represented by the formula (b1-1) are more preferable.

  Examples of the cation contained in the acid generator (B) include an onium cation such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Z ⁺ in formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

In these formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent a C _{1 to} C ₃₀ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group. The aliphatic hydrocarbon group may be substituted with a hydroxy group, a C _{1 to} C ₁₂ alkoxy group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, and the saturated cyclic hydrocarbon group is a halogen atom, C ₂ -C ₄ acyl group or glycidyloxy group may be substituted with, the aromatic hydrocarbon group, a halogen atom, hydroxy group, C ₁ -C ₃₆ aliphatic hydrocarbon group, C ₃ -C ₃₆ saturated cyclic hydrocarbon hydrogen radical or C ₁ -C ₁₂ alkoxy group may be substituted.

R ^b7 and R ^b8 each independently represent a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
m2 and n2 each independently represent an integer of 0 to 5.

R ^b9 and R ^b10 each independently represent a C _{1 to} C ₃₆ aliphatic hydrocarbon group or a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group.
R ^b11 represents a hydrogen atom, a C _{1 to} C ₃₆ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group.
The aliphatic hydrocarbon group for R ^{b9 to} R ^b11 is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{3 to} C ₃₆ , more preferably C _{4 to} C ₁₂ .
R ^b12 represents a C _{1 to} C ₁₂ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group. The aromatic hydrocarbon groups, C ₁ -C ₁₂ aliphatic hydrocarbon group, C ₁ -C ₁₂ alkoxy group, C ₃ -C ₁₈ saturated cyclic hydrocarbon group or alkylcarbonyloxy group may be substituted.
R ^b9 and R ^b10 , and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), These rings —CH ₂ — may be replaced by —O—, —S— or —CO—.

R ^{b13 to} R ^b18 each independently represents a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
L ^b11 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When any of o2 to t2 is 2, any of the plurality of R ^{b13 to} R ^b18 may be the same as or different from each other.

  Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

Preferred aliphatic hydrocarbon groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl. It is.
Preferred saturated cyclic hydrocarbon groups are cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group, And an isobornyl group.
Preferred aromatic hydrocarbon groups are phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group, naphthyl group. It is.
Examples of the aliphatic hydrocarbon group (aralkyl group) whose substituent is an aromatic hydrocarbon group include a benzyl group.
Examples of the ring formed by R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
^Examples of the ring formed by R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) In (1-1), v2 = w2 = x2 = 0) is more preferable.

式（ｂ２−１−１）中、
Ｒ^b19〜Ｒ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、Ｃ₁〜Ｃ₃₆脂肪族炭化水素基、Ｃ₃〜Ｃ₃₆飽和環状炭化水素基又はＣ₁〜Ｃ₁₂アルコキシ基を表す。
脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_１２であり、飽和環状炭化水素基は、好ましくはＣ_４〜Ｃ_３６である。
前記脂肪族炭化水素基は、ヒドロキシ基、Ｃ₁〜Ｃ₁₂アルコキシ基又はＣ₆〜Ｃ₁₈芳香族炭化水素基で置換されていてもよい。
前記飽和環状炭化水素基は、ハロゲン原子、Ｃ₂〜Ｃ₄アシル基又はグリシジルオキシ基で置換されていてもよい。
ｖ２〜ｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。ｖ２〜ｘ２のいずれかが２以上のとき、それぞれ、複数のＲ^b19〜Ｒ^b21のいずれかは、互いに同一でも異なってもよい。
なかでも、Ｒ^b19〜Ｒ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、Ｃ₁〜Ｃ₁₂アルキル基又はＣ₁〜Ｃ₁₂アルコキシ基である。

In formula (b2-1-1),
R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₃₆ aliphatic hydrocarbon group, a C _{3 to} C ₃₆ saturated cyclic hydrocarbon group, or a C _{1 to} C ₁₂ represents an alkoxy group.
The aliphatic hydrocarbon group is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{4 to} C ₃₆ .
The aliphatic hydrocarbon group, hydroxy group, may be substituted by C ₁ -C ₁₂ alkoxy or C ₆ -C ₁₈ aromatic hydrocarbon group.
The saturated cyclic hydrocarbon group may be substituted with a halogen atom, a C ₂ -C ₄ acyl group or a glycidyloxy group.
v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). When any one of v2 to x2 is 2 or more, any one of the plurality of R ^{b19 to} R ^b21 may be the same as or different from each other.
Among these, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₁₂ alkyl group, or a C _{1 to} C ₁₂ alkoxy group.

Specific examples of the cation (b2-1-1) include the following.

Specific examples of the cation (b2-2) include the following.

Specific examples of the cation (b2-3) include the following.

Specific examples of the cation (b2-4) include the following.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but any one of anion (b1-1-1) to anion (b1-1-9) and a cation (b2-1-1), and an anion ( A combination of any one of b1-1-3) to (b1-1-5) and a cation (b2-3) is preferable.

  Preferred acid generators (B1) are those represented by formula (B1-1) to formula (B1-17). Among them, acid generators (B1-1), (B1-2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) containing a triphenylsulfonium cation ) Is more preferable.

  Such an acid generator can be produced by a method known in the art and a method according to the method.

  The content of the acid generator (B) is preferably 1 part by mass (more preferably 3 parts by mass or more), preferably 30 parts by mass with respect to 100 parts by mass of the total amount of the resin (A1) and the resin (A2). Part or less (more preferably 25 parts by weight or less).

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention suitably contains a basic compound (C).
The content of the basic compound (C) is preferably about 0.01 to 1% by mass based on the solid content of the resist composition.

  The basic compound (C) is preferably a basic nitrogen-containing organic compound (for example, an amine). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be any of an amino group bonded to an aromatic ring such as aniline and a heteroaromatic amine such as pyridine. Preferable basic compound (C) includes an aromatic amine represented by the formula (C2), particularly an aniline represented by the formula (C2-1).

ここで、Ａｒ^c1は、芳香族炭化水素基を表す。
Ｒ^c5及びＲ^c6は、それぞれ独立に、水素原子、脂肪族炭化水素基（好ましくはアルキル基又はシクロアルキル基）、飽和環状炭化水素基又は芳香族炭化水素基を表す。但し前記脂肪族炭化水素基、前記飽和環状炭化水素基又は前記芳香族炭化水素基の水素原子は、ヒドロキシ基、アミノ基又はＣ₁〜Ｃ₆アルコキシ基で置換されていてもよく、前記アミノ基は、Ｃ₁〜Ｃ₄アルキル基で置換されていてもよい。
前記脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_６程度であり、前記飽和環状炭化水素基は、好ましくはＣ_５〜Ｃ_１０程度であり、前記芳香族炭化水素基は、好ましくはＣ_６〜Ｃ_１０程度である。
Ｒ^c7は、脂肪族炭化水素基（好ましくはアルキル基又はシクロアルキル基）、アルコキシ基、飽和環状炭化水素基又は芳香族炭化水素基を表す。但し脂肪族炭化水素基、アルコキシ基、飽和環状炭化水素基及び芳香族炭化水素基の水素原子は、上記と同様の置換基を有していてもよい。
ｍ３は０〜３の整数を表す。ｍ３が２以上のとき、複数のＲ^c7は、互いに同一でも異なってもよい。
Ｒ^c7の脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基の好ましい炭素数は、上記と同じであり、Ｒ^c7のアルコキシ基は、好ましくはＣ_１〜Ｃ_６程度である。

Here, Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 each independently represents a hydrogen atom, an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), a saturated cyclic hydrocarbon group or an aromatic hydrocarbon group. However, the hydrogen atom of the aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group or the aromatic hydrocarbon group may be substituted with a hydroxy group, an amino group or a C _{1 to} C ₆ alkoxy group, and the amino group it may be substituted by C ₁ -C ₄ alkyl group.
The aliphatic hydrocarbon group is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{5 to} C ₁₀ , and the aromatic hydrocarbon group is preferably C ₆ it is a ~C about _10.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), an alkoxy group, a saturated cyclic hydrocarbon group, or an aromatic hydrocarbon group. However, the hydrogen atom of an aliphatic hydrocarbon group, an alkoxy group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group may have a substituent similar to the above.
m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R ^c7 may be the same as or different from each other.
Aliphatic hydrocarbon group R ^c7, preferable number of carbon atoms of the saturated cyclic hydrocarbon group and the aromatic hydrocarbon group are the same as above, an alkoxy group of R ^c7 is independently in, preferably about C ₁ -C _6.

Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine.
Examples of aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine and the like.
Of these, diisopropylaniline (particularly 2,6-diisopropylaniline) is preferable.

Examples of the basic compound (C) include compounds represented by the formulas (C3) to (C11).

here,
R ^c8 represents any of the groups described for R ^c7 above.
R ^c9 , R ^c10 , R ^{c11 to} R ^c14 , R ^{c16 to} R ^c19 and R ^c22 bonded to the nitrogen atom each independently represent any of the groups described for R ^c5 and R ^c6 .
R ^c20 , R ^c21 and R ^{c23 to} R ^c28 bonded to the aromatic carbon each independently represents any of the groups described for R ^c7 .
o3 to u3 each independently represents an integer of 0 to 3. When any of o3 to u3 is 2 or more, any of the plurality of R ^{c20 to} R ^c28 may be the same as or different from each other.
R ^c15 represents an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group or an alkanoyl group.
n3 represents an integer of 0 to 8. When n3 is 2 or more, the plurality of R ^c15 may be the same as or different from each other.
The aliphatic hydrocarbon group for R ^c15 is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{3 to} C ₆ , and the alkanoyl group is preferably C _{2 to} C _6. Degree.
L ^c1 and L ^c2 are each independently a divalent aliphatic hydrocarbon group (preferably an alkylene group), —CO—, —C (═NH) —, —C (═NR ^c3 ) —, —S—. , -SS- or a combination thereof. The divalent aliphatic hydrocarbon group is preferably about C _{1 to} C ₆ .
R ^c3 represents a C ₁ -C ₄ alkyl group.

  Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctyl Amine, methyl dinonyl amine, methyl didecyl amine, ethyl dibutyl amine, ethyl dipentyl amine, ethyl di Silamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylene Examples include diamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.

Examples of the compound (C4) include piperazine.
Examples of the compound (C5) include morpholine.
Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound (C7) include 2,2′-methylenebisaniline.
Examples of the compound (C8) include imidazole and 4-methylimidazole.
Examples of the compound (C9) include pyridine and 4-methylpyridine.
Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, and 1,2-di. (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine and the like can be mentioned.
Examples of the compound (C11) include bipyridine.

<Solvent (sometimes referred to as "solvent (E)")
The resist composition of the present invention may contain the solvent (E) in an amount of 90% by mass or more in the composition. The resist composition of the present invention containing the solvent (E) is suitable for producing a thin film resist. The content of the solvent (E) is 90% by mass or more (preferably 92% by mass or more, more preferably 94% by mass or more) and 99.9% by mass or less (preferably 99% by mass or less) in the composition.
The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may be used individually by 1 type, and may use 2 or more types together.

<Other components (hereinafter sometimes referred to as “other components (F)”)>
The resist composition of this invention may contain the other component (F) as needed. The component (F) is not particularly limited, and additives known in the resist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
A step of applying the above-described resist composition of the present invention on a substrate;
Removing the solvent from the composition after coating to form a composition layer;
Exposing the composition layer using an exposure machine;
Heating the composition layer after exposure,
A step of developing the heated composition layer using a developing device is included.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate or by using a decompression device to form a composition layer from which the solvent has been removed. As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. The exposure light source emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser, etc.) Various types of laser beam can be used, such as those that convert the wavelength of the laser beam from) to radiate a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region.

The composition layer after the exposure is subjected to heat treatment for promoting the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The alkaline developer used here may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).
After development, it is preferable to rinse with ultrapure water to remove water remaining on the substrate and the pattern.

<Application>
The chemically amplified resist composition of the present invention exhibits a resolution equal to or higher than that of conventional products, and provides good line edge roughness and an excellent exposure margin. Therefore, it is suitable for excimer laser lithography such as ArF and KrF and ArF immersion exposure lithography. It can be used as a suitable chemically amplified photoresist composition. In addition to immersion exposure, it can also be used for dry exposure. Furthermore, it can be used for double imaging and is industrially useful.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
In Examples and Comparative Examples, “%” and “part” representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined under the following conditions using gel permeation chromatography.

Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL- M 3 linked + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

  The number average molecular weight is a value measured by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation, HLC-8200) and measured in terms of polystyrene by RI and UV detection.

  Moreover, the structure of the compound was confirmed by NMR (JEOL GX-270 type or EX-270 type) and mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type). .

(Synthesis of acid generator B1)
While mixing a mixture of 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water in an ice bath, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise thereto. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.7%). To 1.9 parts of the obtained sodium difluorosulfoacetate (purity 62.7%) and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added and stirred for 2 hours. did.
On the other hand, 0.2 part of sodium hydride was added to a mixture of 1.1 parts of 3-hydroxyadamantylmethanol and 5.5 parts of N, N-dimethylformamide, stirred for 2 hours, and the difluoro obtained previously. A solution containing sodium sulfoacetate was added. The resulting mixture was stirred for 15 hours, and the resulting difluorosulfoacetic acid-3-hydroxy-1-adamantylmethyl ester sodium salt was directly used in the next reaction.

  To the obtained difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt solution, 17.2 parts of chloroform and 2.9 parts of a 14.8% aqueous triphenylsulfonium chloride solution were added. After stirring for 15 hours, the mixture was separated to recover the organic layer. On the other hand, the separated aqueous layer was extracted with 6.5 parts of chloroform, and the organic layer was recovered. The obtained organic layers were combined and washed with ion-exchanged water, and the organic layer was separated and collected, and further concentrated. To the concentrated solution, 5.0 parts of tert-butyl methyl ether was added, stirred, and then filtered to obtain 0.2 parts of acid generator B1 as a white solid.

(Synthesis of acid generator B2)
While adding 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water in an ice bath, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise thereto. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The resulting solution was concentrated to obtain 164.8 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.6%). The obtained sodium difluorosulfoacetate salt 5.0 parts (purity 62.6%), 4-oxo-1-adamantanol 2.6 parts and ethylbenzene 100 parts were added, concentrated sulfuric acid 0.8 part was added, Heated to reflux for 30 hours. The obtained mixture was cooled and then filtered to collect a solid, which was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. . As a result of purity analysis by ¹ H-NMR, the purity was 35.6%.

  5.4 parts (purity 35.6%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt was added to 16 parts acetonitrile and 16 parts ion-exchanged water. To this, 1.7 parts of triphenylsulfonium chloride, 5 parts of acetonitrile and 5 parts of ion-exchanged water were added. This was stirred for 15 hours, concentrated, extracted with 142 parts of chloroform, and separated to recover the organic layer. The collected organic layer was washed with ion-exchanged water, and the obtained organic layer was further concentrated. The concentrated solution was repulped with 24 parts of tert-butyl methyl ether to obtain 1.7 parts of acid generator B2 as a white solid.

(Synthesis of acid generator B3)
3.51 parts of 3-hydroxy-1-adamantanecarboxylic acid and 75 parts of anhydrous THF were charged and stirred at 23 ° C. for 30 minutes. Next, a mixed solution of 2.89 parts of carbonyldiimidazole and 50 parts of anhydrous THF was added dropwise at 23 ° C., and the mixture was stirred at 23 ° C. for 4 hours. The obtained reaction solution was dropped into a mixed solution of 2,2-difluoro-2-sulfoethanol sodium salt 6.04 parts (purity 60%) and anhydrous THF 50 parts at 54-60 ° C. over 25 minutes, Heated at 65 ° C. for 18 hours, cooled and filtered. The obtained filtrate was concentrated, and the concentrate was fractionated into a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfone. 2.99 parts of nat were obtained.
Sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfonate (1.0 part) and chloroform (30 parts) were charged and stirred at 23 ° C. for 30 minutes. Next, 6.3 parts of triphenylsulfonium chloride (13.1% aqueous solution) was stirred at 23 ° C. for 12 hours, and then separated. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Then, 1 part of magnesium sulfate was added, stirred at 23 ° C. for 30 minutes and filtered, and the filtrate was concentrated to obtain 1.6 parts of compound (B3).

Moreover, the monomers used for the synthesis | combination of resin are as follows.

[Synthesis of Resin A1]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and 1.5 mass times dioxane was added to the total mass of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers, and this was added at 78 ° C. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times, the weight average molecular weight (Mw) is 8012, and the dispersity (Mw / Mn) is 1.41. A copolymer having a yield of 70% was obtained. This copolymer is referred to as “resin A1”.

[Synthesis of Resin A2]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and 1.5 mass times dioxane was added to the total mass of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 4 mol% and 12 mol%, respectively, with respect to the total number of moles of all monomers. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 3131 and Mw / Mn of 1.46. Obtained at a rate of 69%. This copolymer is referred to as "resin A2."

[Synthesis of Resin A3]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and 1.5 mass times dioxane was added to the total mass of all monomers to prepare a solution. Add azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators at 0.8 mol% and 2.4 mol%, respectively, with respect to the total number of moles of all monomers, This was heated at 60 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol three times to obtain a copolymer having a weight average molecular weight of 20955 and Mw / Mn of 1.48 in a yield of 72%. It was. This copolymer is referred to as “resin A3”.

[Synthesis of Resin A4]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 30: 10: 10: 20: 30, and 1.5 mass times dioxane is added to the total mass of all monomers. It was set as the solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 8120 and Mw / Mn of 1.52. Obtained at a rate of 71%. This copolymer is referred to as “resin A4”.

[Synthesis of Resin A5]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 30: 10: 10: 20: 30, and 1.5 mass times dioxane is added to the total mass of all monomers. It was set as the solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 4 mol% and 12 mol%, respectively, with respect to the total number of moles of all monomers. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to purify it, and a copolymer having a weight average molecular weight of 3050 and Mw / Mn of 1.55 is collected. Obtained at a rate of 73%. This copolymer is referred to as “resin A5”.

[Synthesis of Resin A6]
Monomer A, monomer B, and monomer D were charged at a molar ratio of 50:25:25, and 1.5 mass times dioxane was added to the total mass of all monomers to obtain a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 8112 and Mw / Mn of 1.54. Obtained at a rate of 55%. This copolymer is referred to as “resin A6”.

[Synthesis of Resin A7]
Monomer A, monomer G, monomer C and monomer D were charged at a molar ratio of 37: 10: 23: 30, and 1.5 mass times dioxane was added to the total mass of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 4 mol% and 12 mol%, respectively, with respect to the total number of moles of all monomers. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to obtain a copolymer having a weight average molecular weight of 3431 and Mw / Mn of 1.56. Obtained at a rate of 65%. This copolymer is referred to as “resin A7”.

[Synthesis of Resin A8]
Monomer A, monomer G, monomer C and monomer D were charged at a molar ratio of 37: 10: 23: 30, and 1.5 mass times dioxane was added to the total mass of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers, and this was added at 78 ° C. For about 5 hours. Thereafter, the reaction solution is purified by pouring it into a mixed solvent of a large amount of methanol and water three times to purify it, and a copolymer having a weight average molecular weight of 8312 and Mw / Mn of 1.51 is collected. Obtained at a rate of 71%. This copolymer is referred to as Resin A8.

[Synthesis of Resin A9]
Monomer A, monomer B, monomer C, and monomer D were charged at a molar ratio of 35: 12: 23: 30, and 1.5 weight times dioxane of the total monomer amount was added to obtain a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 0.5 mol% and 1.5 mol%, respectively, and heated at 60 ° C. for about 5 hours. did. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (4: 1) and precipitating three times, the weight average molecular weight is 26673, and the dispersity (Mw / Mn) is 2. A copolymer of .70 was obtained in a yield of 87%. This copolymer is referred to as “resin A9”.

[Synthesis of Resin A10]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and dioxane was added in an amount 1.5 times the total weight of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 0.5 mol% and 1.5 mol%, respectively, with respect to the total number of moles of all monomers, and at 60 ° C. Heated for about 5 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (1: 1) and precipitating three times, the weight average molecular weight is 26865, and Mw / Mn is 1.98. The copolymer was obtained with a yield of 73%. This copolymer is referred to as “resin A10”.

[Synthesis of Resin A11]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and dioxane was added in an amount 1.5 times the total weight of all monomers to prepare a solution. Thereto, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 0.5 mol% and 1.5 mol%, respectively, with respect to the total number of moles of all monomers, and at 60 ° C. Heated for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol and precipitating 5 times to obtain a copolymer having a weight average molecular weight of 25955 and Mw / Mn of 1.48 in a yield of 55%. It was. This copolymer is referred to as “resin A11”.

[Synthesis of Resin A12]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and dioxane was added in an amount 1.5 times the total weight of all monomers to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers, and heated at 75 ° C. for about 5 hours. did. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (7: 3) and precipitating three times, the weight average molecular weight is 8123, and Mw / Mn is 2.24. The copolymer was obtained with a yield of 75%. This copolymer is referred to as “resin A12”.

[Synthesis of Resin A13]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and dioxane was added in an amount 1.5 times the total weight of all monomers to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers, and heated at 75 ° C. for about 5 hours. did. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (4: 1) and precipitating three times, the weight average molecular weight is 8025, and Mw / Mn is 1.52. The copolymer was obtained with a yield of 70%. This copolymer is referred to as “resin A13”.

[Synthesis of Resin A14]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and dioxane was added in an amount 1.5 times the total weight of all monomers to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers, and heated at 75 ° C. for about 5 hours. did. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol and precipitating three times to obtain a copolymer having a weight average molecular weight of 8189 and Mw / Mn of 1.42 in a yield of 58%. It was. This copolymer is referred to as “resin A14”.

  Table 1 shows the charged amount (mol), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each monomer when the total charged monomer amount of the resin is 100 mol.

Examples and Comparative Examples Each component in Table 2 was mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition. Table 3 shows S ¹ / T ¹ , S ² / T ² , S ³ / T ³ , the difference in weight average molecular weight (ΔMw) and the difference in dispersion (ΔMw / Mn) of the two resins used in each example. Shown in

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline.
<Solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic antireflective coating having a thickness of 78 nm. Formed. Next, the above resist composition was spin-coated on this organic antireflection film so that the film thickness after drying was 0.15 μm. After applying the resist solution, it was pre-baked (PB) for 60 seconds at a temperature described in the “PB” column of Table 4 on a direct hot plate.
The obtained wafer was exposed to a line and space pattern using an ArF excimer stepper [FPA5000-AS3; manufactured by Canon Inc., NA = 0.75, 3/4 Annular] while changing the exposure stepwise.

  After exposure, post-exposure baking (PEB) is performed for 60 seconds on the hot plate at the temperature indicated in the “PEB” column of Table 4, and then paddles are added for 60 seconds with a 2.38 wt% tetramethylammonium hydroxide aqueous solution. Developed.

  The dark field pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope. The results are shown in Table 4. The dark field pattern referred to here is obtained by exposure and development through a reticle having a glass surface (translucent portion) formed in a line form on the outside with a chromium layer (light-shielding layer) as a base, and thus exposure development. The rest is a pattern in which the resist layer around the line and space pattern is left. Effective sensitivity: The exposure amount at which a 100 nm line and space pattern is 1: 1 is shown.

  Resolution evaluation: 100 nm line and space pattern was exposed at an exposure amount of 1: 1, the resist pattern was observed with a scanning electron microscope, and a comparative example was used as a reference (indicated by Δ). Those that were resolved were judged as ◯, and those that were equivalent were judged as △.

  Line edge roughness evaluation (LER): The surface of the resist pattern after the lithography process is observed with a scanning electron microscope, and a comparative example is used as a reference (indicated by Δ). Equivalent ones were evaluated as Δ, and non-smooth ones as X.

  Exposure margin evaluation: Create a graph of sensitivity and line width when exposed at an exposure amount at which a 100 nm line and space pattern is 1: 1, and use a comparative example as a reference (indicated by Δ). A case where the slope of the graph was gentle was judged as ◯, a case where the slope was the same as Δ, and a case where the slope of the graph was steep was judged as ×.

  According to the chemically amplified photoresist composition of the present invention, a pattern having excellent resolution, line edge roughness, and exposure margin can be formed.

Claims (20)

Containing an acid generator, a resin (A1) and a resin (A2);
Resin (A1) is a resin obtained by polymerizing (a1), (a2) and (a3),
Resin (A2) is a resin obtained by polymerizing (a1), (a2) and (a3),
The weight average molecular weight of the resin (A1) is smaller than the weight average molecular weight of the resin (A2), and the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is 3,000 or more;
A chemically amplified photoresist composition that satisfies the formulas (1), (2), and (3).
(A1): Acrylic monomer having a C ₆ -C ₂₀ saturated cyclic hydrocarbon group that becomes alkali-soluble by the action of an acid (a2): Acrylic monomer having an adamantyl group substituted with a hydroxyl group (a3): Lactone ring Acrylic monomer having 0.995 <S ¹ / T ¹ <1.005 (1)
0.995 <S ² / T ² <1.005 (2)
0.995 <S ³ / T ³ <1.005 (3)
S ¹ : In resin (A1), the charged amount (mol) of (a1) when the total amount of charged monomers of resin (A1) is 100 mol
S ² : Charge amount (mol) of (a2) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
S ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
T ¹ : In resin (A2), charged amount (mol) of (a1) when the total amount of charged monomers of resin (A2) is 100 mol
T ² : In the resin (A2), the charged amount (mol) of (a2) when the total amount of charged monomers of the resin (A2) is 100 mol
T ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A2) is 100 mol in resin (A2) Containing an acid generator, a resin (A1) and a resin (A2);
Resin (A1) is a resin obtained by polymerizing (a1), (a2) and (a3),
Resin (A2) is a resin obtained by polymerizing (a1), (a2) and (a3),
The weight average molecular weight of the resin (A1) is smaller than the weight average molecular weight of the resin (A2), the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is less than 1,000, and , the difference in the degree of dispersion of the dispersion degree and the resin (a 2) of the resin (A1) is 0.1 or more,
A chemically amplified photoresist composition that satisfies the formulas (1), (2), and (3).
(A1): Acrylic monomer having a C ₆ -C ₂₀ saturated cyclic hydrocarbon group that becomes alkali-soluble by the action of an acid (a2): Acrylic monomer having an adamantyl group substituted with a hydroxyl group (a3): Lactone ring Acrylic monomer having 0.995 <S ¹ / T ¹ <1.005 (1)
0.995 <S ² / T ² <1.005 (2)
0.995 <S ³ / T ³ <1.005 (3)
S ¹ : In resin (A1), the charged amount (mol) of (a1) when the total amount of charged monomers of resin (A1) is 100 mol
S ² : Charge amount (mol) of (a2) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
S ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
T ¹ : In resin (A2), charged amount (mol) of (a1) when the total amount of charged monomers of resin (A2) is 100 mol
T ² : In the resin (A2), the charged amount (mol) of (a2) when the total amount of charged monomers of the resin (A2) is 100 mol
T ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A2) is 100 mol in resin (A2) The chemically amplified photoresist composition according to claim 1 or 2, wherein the acid generator is an acid generator represented by the formula (B1).

[In Formula (B1), Q ¹ and Q ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — of the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. .
Y represents an optionally substituted C ₁ -C ₁₈ aliphatic hydrocarbon group or an optionally substituted C ₃ -C ₁₈ saturated cyclic hydrocarbon group, the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ] Containing an acid generator, a resin (A1) and a resin (A2);
The acid generator is an acid generator represented by the formula (B2),
Resin (A1) is a resin obtained by polymerizing (a1), (a2) and (a3),
Resin (A2) is a resin obtained by polymerizing (a1), (a2) and (a3),
The weight average molecular weight of the resin (A1) is smaller than the weight average molecular weight of the resin (A2);
Satisfying formula (1), formula (2) and formula (3),
The (a1) is a monomer represented by the formula (a1-1) or a monomer represented by the formula (a1-2), and the monomer represented by the formula (a1-2) is 1-ethyl- A chemically amplified photoresist composition which is 1-cyclohexyl acrylate or 1-ethyl-1-cyclohexyl methacrylate.
(A1): Acrylic monomer having a C ₆ -C ₂₀ saturated cyclic hydrocarbon group that becomes alkali-soluble by the action of an acid (a2): Acrylic monomer having an adamantyl group substituted with a hydroxyl group (a3): Lactone ring Acrylic monomer having 0.995 <S ¹ / T ¹ <1.005 (1)
0.995 <S ² / T ² <1.005 (2)
0.995 <S ³ / T ³ <1.005 (3)
S ¹ : In resin (A1), the charged amount (mol) of (a1) when the total amount of charged monomers of resin (A1) is 100 mol
S ² : Charge amount (mol) of (a2) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
S ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A1) is 100 mol in resin (A1)
T ¹ : In resin (A2), charged amount (mol) of (a1) when the total amount of charged monomers of resin (A2) is 100 mol
T ² : In the resin (A2), the charged amount (mol) of (a2) when the total amount of charged monomers of the resin (A2) is 100 mol
T ³ : Charge amount (mol) of (a3) when the total amount of charged monomers of resin (A2) is 100 mol in resin (A2)

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and ^* represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10. ]

[In the formula (B2),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — of the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. .
Y ′ represents a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated cyclic hydrocarbon group is —O—, —SO ₂ — or It may be replaced by -CO-.
Z ⁺ represents an organic cation. ]   The chemically amplified photoresist composition according to claim 4, wherein the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is 1,000 or more.   The composition according to claim 4, wherein the difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is 3,000 or more.   The difference between the weight average molecular weight of the resin (A1) and the weight average molecular weight of the resin (A2) is less than 1,000, and the difference between the degree of dispersion of the resin (A1) and the degree of dispersion of the resin (A2) is 0.1. The chemically amplified photoresist composition according to claim 4, which is as described above. The chemically amplified photoresist composition according to claim ¹ , wherein S ¹ / T ¹ , S ² / T ² and S ³ / T ³ are 1. The chemically amplified photoresist composition according to claim 1, wherein (a1) is a monomer represented by formula (a1-1) or a monomer represented by formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and ^* represents a bond to —CO—. Represents a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10. ]   The monomer represented by the formula (a1-1) is 2-methyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl methacrylate, 2 The chemically amplified photoresist composition according to claim 9, which is -isopropyl-2-adamantyl acrylate or 2-isopropyl-2-adamantyl methacrylate.   The chemically amplified photoresist composition according to claim 9, wherein the monomer represented by the formula (a1-2) is 1-ethyl-1-cyclohexyl acrylate or 1-ethyl-1-cyclohexyl methacrylate.   (A2) is 3-hydroxy-1-adamantyl acrylate, 3-hydroxy-1-adamantyl methacrylate, 3,5-dihydroxy-1-adamantyl acrylate, or 3,5-dihydroxy-1-adamantyl methacrylate. 11. The chemically amplified photoresist composition according to any one of 11 above.   The chemically amplified photoresist composition according to any one of claims 1 to 12, wherein (a2) is 3,5-dihydroxy-1-adamantyl acrylate or 3,5-dihydroxy-1-adamantyl methacrylate. 14. (a3) is a monomer represented by the formula (a3-1), a monomer represented by the formula (a3-2), or a monomer represented by the formula (a3-3). The chemically amplified photoresist composition described.

[In Formula (a3-1)-Formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or ^* —O— (CH ₂ ) _k3 —CO—O—, k3 represents an integer of 1 to 7, and ^* represents a bond to —CO—. Represents a hand.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents a C _{1 to} C ₄ aliphatic hydrocarbon group.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or a C ₁ -C ₄ aliphatic hydrocarbon group.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 may be the same as or different from each other. ] The chemically amplified photoresist composition according to claim 3, comprising an acid generator in which Z ⁺ is an arylsulfonium cation. The chemically amplified photoresist composition according to claim 3, wherein Y ¹ is a group having an adamantane group or an oxo-adamantane group.   The chemically amplified photoresist composition according to any one of claims 1 to 16, wherein the content of the acid generator is 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the resin.   Furthermore, the chemical amplification type photoresist composition in any one of Claims 1-17 containing a nitrogen-containing basic compound.   The chemically amplified photoresist composition according to claim 18, wherein the nitrogen-containing basic compound is diisopropylaniline. Applying the chemically amplified photoresist composition according to claim 1 on a substrate;
Removing the solvent from the composition after coating to form a composition layer;
Exposing the composition layer using an exposure machine;
Heating the composition layer after exposure,
The pattern formation method characterized by including the process of developing the composition layer after a heating using a image development apparatus.