JP6159833B2 - Resist composition and method for producing resist pattern - Google Patents

Description

The present invention relates to a resist composition and a method for producing a resist pattern using the resist composition.

In recent years, as a semiconductor microfabrication technique, an optical lithography technique using short-wavelength light such as an ArF excimer laser (wavelength: 193 nm) as an exposure source has been actively studied. Examples of the resist composition used in such a photolithography technique include a resin composed of a structural unit represented by the formula (u-A) and a structural unit represented by the formula (u-B), and a formula (u A resin comprising a structural unit represented by -B), a structural unit represented by formula (u-C), and a structural unit represented by formula (u-D), an acid generator, and a solvent. A resist composition is known (Patent Document 1).
.

JP 2010-197413 A

In some cases, a resist pattern manufactured from the above-described resist composition known in the related art does not necessarily satisfy the mask error factor (MEF).

As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention.
That is, the present invention includes the following inventions.
[1] A structural unit represented by formula (aa), a structural unit represented by formula (a1-1), and a formula (
at least one structural unit (ab) selected from the group consisting of structural units represented by a1-2)
And a resin (A1) having
It has no structural unit represented by the formula (aa), has a structural unit (ab) having the same structure as the structural unit (ab) of the resin (A1), is insoluble or hardly soluble in an alkaline aqueous solution, Resin composition that is soluble in an alkaline aqueous solution by the action of (A2); and a resist composition that contains an acid generator and satisfies the relationship represented by formula (X1).
0.8 <α / β <1.2 (X1)
[In formula (X1), α represents the content ratio [mol%] of the structural unit (ab) of the resin (A1) to the total structural unit of the resin (A1).
β is the structural unit (ab) of the resin (A2) with respect to all the structural units of the resin (A2).
) And the content ratio [mol%] of the structural unit having the same structure. ]
[In the formula (aa)
R ^aa1 represents a hydrogen atom or a methyl group.
A ^aa1 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-1
) Represents a group represented by
(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
R ^aa2 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent. ]

[In the formula (a1-1),
L ^a1 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7). * Is a bond to a carbonyl group.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms. m1 represents the integer of 0-14.
In formula (a1-2),
L ^a2 is an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
) Represents a group represented by * Is a bond to a carbonyl group.
R ^a5 represents a hydrogen atom or a methyl group.
R ^a7 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]
[2] The above [1], wherein A ^{aa1 in the} formula (aa) is an alkanediyl group having 1 to 6 carbon atoms.
The resist composition as described.
[3] The resist composition according to [1], wherein A ^{aa1 in the} formula (aa) is an ethylene group.
[4] Said [1]-[beta] where the above-mentioned alpha and beta satisfy the relation expressed by the following formulas (X2).
[3] The resist composition according to any one of [3].
0.9 <α / β <1.1 (X2)
[5] The structural unit (ab) is a structural unit represented by the formula (a1-1).
1]-[4] The resist composition in any one of.
[6] The resist composition according to any one of [1] to [5], wherein the acid generator is an acid generator represented by the formula (B1).
[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ]
[7] The resist composition according to [6], wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent.
[8] The resist composition according to any one of [1] to [7], further containing a solvent. [9] (1) The resist composition according to any one of [1] to [8] is applied on a substrate. The process of
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

According to the resist composition of the present invention, a resist pattern having an excellent mask error factor (MEF) can be produced. In addition, a resist pattern with a small number of defects can be manufactured.

A common group is defined in various compounds shown in the present specification. In this definition, the numerical value attached to “C” indicates the number of carbon atoms of each group.

In the present specification, the “hydrocarbon group” refers to an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group is further classified into a chain type and an alicyclic type. Unless otherwise defined, the term “aliphatic hydrocarbon group” in the present specification includes an aliphatic hydrocarbon group in which a chain and alicyclic aliphatic hydrocarbon group are combined.

Of the chain aliphatic hydrocarbon groups (chain hydrocarbon groups), the monovalent one is typically an alkyl group. Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), Propyl group (C ₃ ), butyl group (C ₄ ), pentyl group (C ₅ ), hexyl group (C ₆ ), heptyl group (
C ₇ ), octyl group (C ₈ ), decyl group (C ₁₀ ), dodecyl group (C ₁₂ ), hexadecyl group (C ₁₄ ), pentadecyl group (C ₁₅ ), hexyldecyl group (C ₁₆ ), heptadecyl group ( C ₁₇
) And octadecyl group (C ₁₈ ), etc., and these may be linear or branched.
Unless particularly limited, this chain hydrocarbon group may contain a carbon-carbon double bond in a part of the alkyl groups exemplified herein, but does not have such a carbon-carbon double bond, etc. Of these, a chain hydrocarbon group, particularly a saturated alkyl group, is preferred. The divalent chain hydrocarbon group corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

Monovalent alicyclic aliphatic hydrocarbon groups (hereinafter sometimes referred to as “alicyclic hydrocarbon groups”) typically remove one hydrogen atom from an alicyclic hydrocarbon. It is a group. The alicyclic hydrocarbon group may be an unsaturated alicyclic hydrocarbon group containing about one carbon-carbon unsaturated bond, or may be a saturated alicyclic hydrocarbon group containing no such carbon-carbon unsaturated bond. The alicyclic hydrocarbon group referred to in the present specification is preferably saturated. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Here, an alicyclic hydrocarbon group will be illustrated by illustrating an alicyclic hydrocarbon before removing a hydrogen atom. The monocyclic alicyclic hydrocarbon is typically a cycloalkane, and cyclopropane (C ₃ ) represented by the following formula (KA-1), cyclobutane represented by the formula (KA-2) ( C ₄ ), formula (KA−
3) Cyclopentane (C ₅ ) represented by Formula (KA-4) and Cyclohexane (C
₆ ), cycloheptane (C ₇ ) represented by formula (KA-5), cyclooctane (C ₈ ) represented by formula (KA-6) and cyclododecane represented by formula (KA-7) ( C ₁₂ ) and the like.
Examples of polycyclic alicyclic hydrocarbons include:
The polycyclic alicyclic hydrocarbon is, for example, a bicyclo [2.2 represented by the following formula (KA-8).
. 1] Heptane (hereinafter sometimes referred to as “norbornane”) norbornene (C ₇ ), formula (
Examples thereof include adamantane (C ₁₀ ) represented by KA-9) and alicyclic hydrocarbons represented by formula (KA-10) to formula (KA-22).
The divalent alicyclic hydrocarbon group corresponds to a group in which two hydrogen atoms are removed from the alicyclic hydrocarbon of the formula (KA-1) to the formula (KA-22).

In the present specification, the aromatic hydrocarbon group is a monovalent aromatic hydrocarbon group, typically an aryl group. Specifically, a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an anthryl group (C ₁₄ ), a biphenyl group (C ₁₂ ), a phenanthryl group (C ₁₄ ), and a fluorenyl group (C ₁₃
) Etc.

The aliphatic hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group.

The halogen atom is a fluorine atom, a chlorine atom, a bromine atom and an iodine atom unless otherwise specified.
As an alkoxy group, a methoxy group (C ₁ ), an ethoxy group (C ₂ ), a propoxy group (C
_3), butoxy _(C 4), a pentyloxy group _(C 5), a hexyloxy group _(C 6), heptyloxy group (C _7), octyloxy group (C _8), decyloxy group (C ₁₀₎ and dodecyl An oxy group (C ₁₂ ) and the like, and these alkoxy groups may be linear or branched.
Examples of the acyl group include an acetyl group (C ₂ ), a propionyl group (C ₃ ), and a butyryl group (C ₄
), Valeryl group (C ₅ ), hexylcarbonyl group (C ₆ ), heptylcarbonyl group (C ₇₎
), Octylcarbonyl group (C ₈ ), decylcarbonyl group (C ₁₀ ), dodecylcarbonyl group (C ₁₂ ) and other alkyl groups and carbonyl groups bonded to each other, benzoyl group (
And those in which an aryl group and a carbonyl group are bonded, such as C ₇ ). Among these acyl groups, an alkyl group and a carbonyl group bonded to each other may be linear or branched.
The aryl group is the same as that exemplified as the aryl group of the aromatic hydrocarbon group described above, and specific examples of the aryloxy group are those in which the aryl group and an oxygen atom are bonded.
Examples of the aralkyl group include a benzyl group (C ₇ ), a phenethyl group (C ₈ ), a phenylpropyl group (C ₉ ), a naphthylmethyl group (C ₁₁ ), and a naphthylethyl group (C ₁₂ ).

The aromatic hydrocarbon group may also have a substituent. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group. Among these, the alkyl group is the same as those exemplified as the chain aliphatic hydrocarbon group, and among the substituents optionally present in the aromatic hydrocarbon group, those other than the alkyl group are aliphatic hydrocarbon groups. The same thing as what was illustrated as a substituent of is mentioned.

Further, “(meth) acrylic monomer” means “CH ₂ ═CH—CO—” or “CH ₂ ═
It means at least one monomer having a structure of “C (CH ₃ ) —CO—”. Similarly "
“(Meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

<Resist composition>
The resist composition of the present invention comprises a resin (hereinafter referred to as “resin (A)”) and an acid generator (hereinafter referred to as “resin (A)”).
Acid generator (B) ”).
Resin (A) contains resin (A1) and resin (A2).
Moreover, it is preferable that the resist composition of this invention contains the solvent (D) and / or a basic compound (C) further.
The resist composition exhibits an effect that a resist pattern having an excellent mask error factor can be produced by containing the resin (A1) and the resin (A2) in combination.

<Resin (A1)>
Resin (A1) consists of structural unit (aa) and structural unit (a1-1) represented by formula (a1-1).
And at least one structural unit (ab) selected from the group consisting of structural units (a1-2) represented by formula (a1-2).

<Structural unit (aa)>
The structural unit (aa) is represented by the following formula (aa).
[In the formula (aa)
R ^aa1 represents a hydrogen atom or a methyl group.
A ^aa1 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-1
) Represents a group represented by
(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represent an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
R ^aa2 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent. ]

Alkanediyl group A ^aa1, for example, the alkanediyl group A ^aa1, methylene group, ethylene group, propane-1,3-diyl, propane-1,2-diyl group, butane -
Linear alkanediyl groups such as 1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane- 1
, 3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-
Examples thereof include branched alkanediyl groups such as diyl group and 2-methylbutane-1,4-diyl group.
The hydrogen atom contained in the alkanediyl group may be substituted with a substituent (a monovalent group other than a hydrogen atom), and examples of the substituent include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. It is done.

The group (a-1) of A ^aa1 includes an atom or an atomic group such as an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, like X ¹⁰ and X ¹¹ .
Examples of the aliphatic hydrocarbon group for A ¹⁰ , A ¹¹ and A ¹² include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, 1-
Examples thereof include a methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.
Examples of the substituent in A ¹⁰ , A ^11, and A ¹² include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.

As the group (a-1) having an oxygen atom,
(* Represents a bond).

As the group (a-1) having a carbonyl group,
(* Represents a bond).

As the group (a-1) having a carbonyloxy group,
(* Represents a bond).

As the group (a-1) having an oxycarbonyl group,
(* Represents a bond).

A ^{aa1 in the} structural unit (aa) is preferably an alkanediyl group having 1 to 6 carbon atoms,
4 alkanediyl groups are more preferred, and methylene groups are even more preferred.

The aliphatic hydrocarbon group for R ^aa2 may partially have a carbon-carbon unsaturated bond,
A saturated aliphatic hydrocarbon group (aliphatic saturated hydrocarbon group) having no carbon-carbon unsaturated bond is preferred. Preferred aliphatic hydrocarbon groups include alkyl groups (the alkyl groups may be straight or branched) and alicyclic hydrocarbon groups.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group.
Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, and the groups shown below.
R ^aa2 may be an aliphatic hydrocarbon group in which two or more of these alkyl groups and alicyclic hydrocarbon groups are combined.

Examples of the substituent for the aliphatic hydrocarbon group of R ^aa2 include a halogen atom, an alkoxy group, an acyl group, and an alkoxycarbonyl group. When R ^aa2 is an aliphatic hydrocarbon group having a substituent, the total number of carbon atoms including the carbon atoms in the substituent is preferably 18 or less. In light of such an upper limit on the number of carbon atoms, specific examples of the halogen atom, alkoxy group, and acyl group can be selected from those already exemplified. The alkoxycarbonyl group is a combination of the exemplified alkoxy group and carbonyl group. Among these substituents, a fluorine atom is preferable, that is, the aliphatic hydrocarbon group of R ^aa2 preferably has a fluorine atom. Examples of the aliphatic hydrocarbon group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, 1,1,
1-trifluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1 , 2,2-tetrafluorobutyl group, 1,1,1,2,2,
3,3-peptafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group,
1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1
, 1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoro Pentyl group, 1,1-
Bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4
, 4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6
, 6-dodecafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group.
Among them, the aliphatic hydrocarbon group having a fluorine atom is preferably a triperfluoromethyl group, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1,1.
, 2,2-pentafluoropropyl group, perfluoropropyl group, 1,1,1,2,2,
3,3-heptafluorobutyl group, perfluorobutyl group, 1,1,1,2,2,3,3
, 4,4-nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group, perfluorooctyl group, and the like, more preferably a C 1-6 perfluoroalkyl group, still more preferably, It is a C1-C3 perfluoroalkyl group.

Here, a specific example of the structural unit (aa) is shown.

In the specific example of the structural unit (aa) represented by any one of the formulas (aa-1) to (aa-14), a structure in which the partial structure M shown below is replaced with the partial structure A shown below unit(
Specific examples of aa) can be mentioned.

The structural unit (aa) is a compound represented by the formula (aa ′) (hereinafter, “compound (a
a ′) ”. )
(All symbols in formula (aa ′) have the same meanings as described above.)

Compound (aa ′) can be produced, for example, by the method represented by the following reaction formula.
The compound represented by the formula (aas-1) and the compound represented by the formula (aas-2) are preferably reacted in a solvent in the presence of a catalyst. As such a solvent, dimethylformamide or the like is used. As the catalyst, potassium carbonate, potassium iodide, or the like may be used.

The compound represented by the formula (aas-1) is preferably one that can be easily obtained from the market (commercial product). Such commercial products include methacrylic acid.
The compound represented by the formula (aas-2) can be produced, for example, by reacting a compound represented by the formula (aas-3) with a compound represented by the formula (aas-4). This reaction is carried out in a solvent in the presence of a base catalyst. The solvent used in this reaction is tetrahydrofuran or the like. As the base catalyst, pyridine or the like is used.
Examples of the compound represented by the formula (aas-3) include chloroacetyl chloride. This chloroacetyl chloride is readily available from the market.
Examples of the compound represented by the formula (aas-4) include 2,2,3,3,4,4,4-
Heptafluoro-1-butanol or the like may be used. This 2,2,3,3,4,4,4
-Heptafluoro-1-butanol is readily available from the market.

<Structural unit (ab)>
The structural unit (ab) is at least one selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). The structural unit (a1-1) and the structural unit (a1-2) are It is represented by the following formula (a1-1) and formula (a1-2).
[In the formula (a1-1),
L ^a1 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7). * Is a bond to a carbonyl group.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
In formula (a1-2),
L ^a2 is an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
) Represents a group represented by * Is a bond to a carbonyl group.
R ^a5 represents a hydrogen atom or a methyl group.
R ^a7 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably an oxygen atom or —O— (CH wherein k1 is an integer of 1 to 4.
₂ ) a group represented by _k1 —CO—O—, more preferably an oxygen atom or —O—CH ₂ —CO
-O-, more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.

The aliphatic hydrocarbon group represented by R ^a6 and R ^a7 is preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms. Includes examples. The aliphatic hydrocarbon groups for R ^a6 and R ^a7 are each independently preferably an alkyl group having 8 or less carbon atoms or an alicyclic hydrocarbon group having 8 or less carbon atoms, more preferably an alkyl group having 6 or less carbon atoms. Or it is an alicyclic hydrocarbon group having 6 or less carbon atoms.
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.
n1 ′ is preferably 0 or 1.

Examples of the structural unit (a1-1) include the following structural units.

A structural unit (a1-1) represented by any one of formula (a1-1-1) to formula (a1-1-38)
In the specific example of the structural unit (aa), as in the specific example of the structural unit (aa), the partial structure M can be replaced with the partial structure A as a specific example of the structural unit (a1-1).

Among these, the structural unit (a1-1) represented by any one of the formula (a1-1-1), the formula (a1-1-2) and the formula (a1-1-3) and the structural unit (a1) -1) in which the partial structure M is replaced by the partial structure A is preferable, and is represented by formulas (a1-1-1) and (a1-1-2).
And the structural unit (a1-1) represented by any one of the formulas (a1-1-3) is more preferred and represented by any one of the formulas (a1-1-1) and (a1-1-2). The structural unit (a1-1) is more preferable. In addition, when the resin (A) having these preferred structural units (a1-1) is produced, when the resin (A) is produced, 2-methyladamantan-2-yl (meth) acrylate,
2-ethyladamantan-2-yl (meth) acrylate, 2-isopropyladamantan-2-yl (meth) acrylate, or the like may be used as a raw material (monomer) for production.

Next, specific examples of the structural unit (a1-2) are shown.
A structural unit (a1-2) represented by any one of formula (a1-2-1) to formula (a1-2-12)
In the specific example of the structural unit (aa), as in the specific example of the structural unit (aa), the partial structure M may be replaced with the partial structure A as a specific example of the structural unit (a1-2).

Among them, the formula (a1-2-1), the formula (a1-2-2), the formula (a1-2-4), and the formula (a
1-2-5) structural unit (a1-2) represented by any one of these structural units (a1)
-2) in which the partial structure M is replaced by the partial structure A, and is preferably represented by the formula (a1-2-4)
And a structural unit represented by any one of formula (a1-2-5) and these structural units (a1
It is more preferable that the partial structure M-2 is replaced with the partial structure A. In order to produce the resin (A) having such a structural unit (a1-2), 1-methyl-2-cyclohexane-1-yl (meth) acrylate or the like may be used as a monomer.

In the resin (A1), the structural unit (aa) and the structural unit (ab) may each be one kind, one may be plural, and the other may be one. Among these, those having one each of the structural unit (aa) and the structural unit (ab) are preferable in that the resin (A1) can be easily produced. Examples of combinations of the structural unit (aa) and the structural unit (ab) are shown in Tables 1 and 2 below. In Table 1, the structural unit (aa) represented by the formula (aa-1) is represented as “(aa-1)” according to the formula number, and the formula (a1-1-1) ), The structural unit (a1-2) represented by the formula (a1-2-1), etc., according to the formula number “(a1-1-1) "," (A1-
2-1) ". For example, the notation “(aa-1) / (aa-3)” is represented by the structural unit (aa), the structural unit represented by the formula (aa-1), and the formula (aa-3). Together with a structural unit.

Structural units (aa) and structural units (100 mol%) relative to all structural units (100 mol%) of the resin (A1)
ab) The content of each is preferably in the range of 5 to 95 mol%, more preferably in the range of 10 to 90 mol%. That is, the content ratio α of the structural unit (ab) to the total structural unit of the resin (A1) [hereinafter referred to as “content ratio α in the resin (A1)” in some cases. ] (Mol%) is preferably in the range of 5 to 95 mol%, more preferably in the range of 10 to 90 mol%. However, the content ratio α in the resin (A1) is the structural unit (a
Content ratio β of b) [hereinafter referred to as “content ratio β in resin (A2)” in some cases. ] (Mol%), it is necessary to satisfy the relationship represented by the formula (X1), and the resin (A2)
It is necessary to determine the content ratio α in the resin (A1) in consideration of the content ratio β in the resin. In addition, such a resin (A1) includes the compound (aa ′) and the monomer for deriving the structural unit (ab) [the structural unit (a1-1) with respect to the total molar amount of all monomers used in the production of the resin (A1). The monomer to be derived and / or the monomer to derive the structural unit (a1-2)] can be produced by adjusting the molar amount used.
In order to obtain the content ratio α in the resin (A1), the following may be performed.
From the amount of each monomer used in producing the resin (A) and the amount of each monomer remaining in the polymerization reaction mixture after the production of the resin (A1), the amount of each monomer consumed in the production of the resin (A1) From the amount of substances of all structural units in the resin (A1) (total amount of monomers consumed for the production of the resin (A1)) and the total amount of monomers consumed for the formation of the structural units (ab),
The content ratio α in the resin (A1) is calculated.
Alternatively, when obtaining the content α of a resin from the resins produced (A1) (A1) ^measures the ratio of the respective structural units by ^{NMR (1 H-NMR, 13} C-NMR) analysis, resin ( The content ratio α in A1) is calculated.

The resin (A1) may have other structural units in addition to the structural unit (aa) and the structural unit (ab). Here, as structural units other than the structural unit (aa), the structural unit (a1-1), and the structural unit (a1-2), which may be contained in the resin (A1), a monomer described later, a known monomer, and the like Examples of the structural unit are derived. Of these, a structural unit derived from an acid stable monomer is preferable, and a structural unit derived from an acid stable monomer (a4) is particularly preferable. When the resin (A1) has an acid stable structural unit, the resist composition containing the resin (A1) is formed on the substrate when the resist composition is applied to the substrate in the production of a resist pattern described later. There is a tendency that the coating film or the composition layer obtained from the coating film is likely to exhibit excellent adhesion with the substrate.
However, when the resin (A1) has other structural units, the content ratio is preferably in the range of 50 mol% or less, more preferably in the range of 30 mol% or less. More preferably, it is not present.

<Resin (A2)>
As described above, the resin (A2) satisfies the following requirements.
(1) having no structural unit (aa);
(2) Insoluble or hardly soluble in alkaline aqueous solution;
(3) Be soluble in an alkaline aqueous solution by the action of an acid;
(4) having the same structural unit (ab) as the resin (A1);
(5) Between the content ratio β (mol%) in the resin (A2) and the content ratio α in the resin (A1),
0.8 <α / β <1.2 (X1)
Satisfy the relationship.

The requirement (1) “having no structural unit (aa)” means that the resin (A2) does not have the structural unit (aa) already shown in the description of the resin (A1). The structural unit (aa) is represented by the formula (aa), and specific examples thereof are as described above.

Requirements (2) and (3) are “insoluble or hardly soluble in an alkaline aqueous solution and soluble in an alkaline aqueous solution by the action of an acid”. A developer used in a method for producing a resist pattern, which will be described later.) Is insoluble or hardly soluble, but becomes soluble in the aqueous alkali solution after being subjected to the action of an acid (hereinafter referred to as “resin” in some cases). (A2) Characteristic ”). Due to the synergistic effect of the resin (A2) characteristics and the effect of the acid generator, this resist composition can produce a resist pattern.
Such a resin (A2) has an acid labile group in the molecule. "Acid labile group" here
The term “means” means a hydrophilic group protected by a protecting group that can be removed by contact with an acid. Examples of the hydrophilic group include a hydroxy group or a carboxy group, and a carboxy group is more preferable. In order to have an acid labile group in the molecule, it is preferable to have a structural unit containing an acid labile group in the molecule (hereinafter sometimes referred to as “structural unit (a1)”).
The structural unit (a1-1) and the structural unit (a1-2) are also structural units containing an acid labile group. That is, the resin (A1) has the same characteristics as the resin (A2) characteristics.

The requirement (4) is that the resin (A2) has the same structural unit (ab) as the resin (A1) used together with the resin (A2). For example, when both the resin (A1) and the resin (A2) have a structural unit represented by the formula (a1-1-3), the formula (a1-1-3)
) Corresponds to the structural unit (ab), and depending on the content ratio of the structural unit represented by the formula (a1-1-3) in the resin (A1) and the resin (A2), α And β,
α / β is calculated. Further, for example, both the resin (A1) and the resin (A2) are represented by the formula (a1-
When the structural unit represented by 1-3) and the structural unit represented by the formula (a1-2-5) are included, the structural unit represented by the formula (a1-1-3) and the formula (a1 -2-5) corresponds to the structural unit (ab), and the structural unit represented by the formula (a1-1-3) and the formula (a
Α and β are determined based on the total content of the resin (A1) and the resin (A2) of the structural unit represented by 1-2-5), and α / β is calculated. The method for obtaining the content ratio α in the resin (A1) is as described above. To obtain the content ratio β in the resin (A2), the resin (A
A method can be similarly used for the content ratio α in 1). That is, the content ratio α in the resin (A1)
The “resin (A1)” may be read as “resin (A2)” and the “content ratio α in the resin (A1)” may be read as “content ratio β in the resin (A2)”.

The requirement (5) is that α and β obtained as described above satisfy the relationship of the formula (X1). The present resist composition containing the resin (A1) and the resin (A2) satisfying this relationship exhibits an effect that a resist pattern having an excellent mask error factor can be produced. When α / β is small, the mask error factor becomes worse due to the difference in dissolution contrast between the resin (A1) and the resin (A2) in the developer after exposure. Similarly, α / β
When is large, the mask error factor is deteriorated as in the case where α / β is small. From this point, α / β more preferably satisfies the relationship represented by the following formula (X2), and more preferably satisfies the relationship represented by the following formula (X3).
0.9 <α / β <1.1 (X2)
0.95 <α / β <1.05 (X3)

<Acid labile group>
In the case where the hydrophilic group is a carboxy group, the acid labile group is such that the hydrogen atom of the carboxy group is replaced with an organic residue, and the atom of the organic residue bonded to —O— of the carboxy group is a tertiary carbon. Examples include groups that are atoms (ie, esters of tertiary alcohols). Among such acid labile groups, preferred acid labile groups are, for example, those represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).
In formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or R ^a1 and R ^a2 are bonded to each other, and the carbon to which they are bonded. 3 to 2 carbon atoms with atoms
A 0 ring is formed. The ring formed by combining R ^a1 and R ^a2 and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group. *
Represents a bond.

The aliphatic hydrocarbon group for R ^{a1 to} R ^a3 is an alkyl group or an alicyclic hydrocarbon group. The specific example of this alkyl group is a C1-C8 range among the already exemplified alkyl groups,
Includes those already exemplified. The alicyclic hydrocarbon group also includes those already exemplified in the range of 8 or less carbon atoms.

The combination of R ^a1 and R ^a2 to form a ring means that the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is any of the followings. The number of carbon atoms in such a ring is preferably in the range of 3-12.

As the acid labile group (1), a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are all alkyl groups, one of these alkyl groups is tert-butyl Group), a 2-alkyladamantan-2-yloxycarbonyl group (
In the formula (1), R ^a1 and R ^a2 are bonded to each other to form an adamantane ring together with the carbon atom to which they are bonded, and R ^a3 is an alkyl group) and 1- (adamantan-1-yl) -1- And alkylalkoxycarbonyl groups (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

On the other hand, examples of the acid labile group in the case where the hydrophilic group is a hydroxy group include those in which a hydrogen atom of the hydroxy group is replaced with an organic residue to become a group containing an acetal structure or a ketal structure. Among such acid labile groups, preferred acid labile groups include, for example, the following formula (2):
(Hereinafter, referred to as “acid-labile group (2)” in some cases).
In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms. R ^b2 and R ^b3 are combined to form a ring having 3 to 20 carbon atoms together with the carbon atom and the oxygen atom to which they are bonded. When the hydrocarbon group includes a methylene group, the methylene group may be replaced by an oxygen atom, a sulfur atom or a carbonyl group, and a methylene group constituting a ring formed by combining R ^b2 and R ^b3 is also , Oxygen atom, sulfur atom or carbonyl group may be substituted. * Represents a bond.

The hydrocarbon group of R ^{b1 to} R ^b3 may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and specific examples thereof include those already exemplified as long as the upper limit of the carbon number is 20 or less. , R ^b1 and R ^b2 are preferably at least one hydrogen atom.
^Examples of the ring formed by combining R ^b2 and R ^b3 include those in which one carbon atom of the ring formed by combining R ^a1 and R ^a2 described above is replaced with one oxygen atom.

Specific examples of the acid labile group (2) include the following groups.

The structural unit (a1) that the resin (A2) has other than the structural unit (ab) is preferably derived from a monomer having an acid labile group and a carbon-carbon double bond, and has an acid labile group. Those derived from (meth) acrylic monomers are more preferred.

As for the structural unit (a1) of the resin (A2), it is preferable that the acid labile group (1) itself has a partial structure of an aliphatic ring having 5 to 20 carbon atoms, like the structural unit (ab). Resin (A1) and resin (A) having a structural unit (ab) containing a sterically bulky acid labile group (1)
By using 2), the present resist composition containing them can produce a resist pattern with better resolution.

The content ratio β of the structural unit (ab) to the total structural unit (100 mol%) of the resin (A2) is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%.
A range of 85 mol% is more preferable. However, the content ratio β in the resin (A2) needs to be determined in consideration of the content ratio α in the resin (A1) already described. In addition, the content ratio β in the resin (A2) needs to be determined in consideration that the resin (A2) satisfies the requirements (2) and (3). Resin having a structural unit (ab) at a content ratio β in the resin (A2) (
A2) adjusts the amount of the structural unit (ab), that is, the monomer that induces the structural unit (a1-1) and / or the structural unit (a1-2), with respect to the total amount of monomers used in producing the resin (A2) Can be manufactured.

Resin (A2) is structural unit (a) which is not the same as structural unit (ab) which resin (A1) has
1-1) and structural units (a1-2) that are not identical to the structural units (ab) of the resin (A1)
) [Structural unit (a1-1) not identical to structural unit (ab) contained in resin (A1) and / or
Or a structural unit (a1-2)]. Structural unit (a1) of resin (A2)
-1) and structural units (a1-2) that the resin (A1) does not have are structural units (a
It does not fall under b). The resin (A2) includes a structural unit (a1-1) and a structural unit (a
In addition to 1-2), it may have a structural unit (a1) [another structural unit (a1)] having an acid labile group. Hereinafter, specific examples of the other structural unit (a1) will be shown by listing monomers that derive the other structural unit (a1).

Examples of the other structural unit (a1) include those derived from a monomer having a norbornene ring represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). Can be mentioned. From the monomer (a1-3), a structural unit (a1) having an acid labile group (1) is derived.
In formula (a1-3),
R ^a9 is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms that may have a hydroxy group, a carboxyl group, a cyano group, or —COOR ^a13 (R ^a13 is an aliphatic hydrocarbon group having 1 to 20 carbon atoms. And the hydrogen atom constituting the aliphatic hydrocarbon group may be substituted with a hydroxy group, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. .)
R ^a10 , R ^a11 and R ^a12 each independently represent an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or R ^a10 and R ^a11 are bonded together with the carbon atom to which they are bonded. To form a ring having 3 to 20 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. .

Examples of the alkyl group having a hydroxyl group for R ^a9 include a hydroxymethyl group and a 2-hydroxyethyl group.
The aliphatic hydrocarbon group for R ^{a10 to} R ^a12 may be either a chain hydrocarbon group (for example, an alkyl group) or an alicyclic hydrocarbon group, and specific examples thereof are already in the range of 20 or less carbon atoms. Includes examples.
The ring formed by combining R ^a10 and R ^a11 is preferably an aliphatic ring, and more specifically, a cyclohexane ring and an adamantane ring are more preferable.

Examples of the alkoxycarbonyl group for R ^a9 include groups in which a carbonyl group is further bonded to the already exemplified alkoxy group such as a methoxycarbonyl group (C ₂ ) and an ethoxycarbonyl group (C ₃ ).

As the monomer (a1-3), 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl Cyclohexyl, 2-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2
-Adamantyl, 5-norbornene-2-carboxylic acid 1- (4-methylcyclohexyl)
-1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4
-Oxocyclohexyl) ethyl and 1- (1-adamantyl) -1-methylethyl 5-norbornene-2-carboxylate and the like.

When the resin (A2) is produced using the monomer (a1-3), the resin (A2) includes a sterically bulky structural unit derived from the monomer (a1-3). Thus, if a resist pattern is manufactured with this resist composition containing resin (A2) which has a three-dimensionally bulky structural unit, a resist pattern can be obtained with a better resolution. Furthermore, since a rigid norbornane ring can be introduced into the main chain of the resin (A2) by using the monomer (a1-3), this resist composition containing the resin (A2) is a resist having excellent dry etching resistance. There is a tendency that a pattern is easily obtained.

As described above, from the viewpoint that a resist pattern can be produced with good resolution and a resist pattern excellent in dry etching resistance can be easily obtained, all structural units of the resin (A2) (
100 mol%), the content of the structural unit derived from the monomer (a1-3) is 10 to 10%.
The range is preferably 95 mol%, more preferably 15 to 90 mol%, and still more preferably 20 to 85 mol%.

Examples of the monomer having an acid labile group (2) include a monomer represented by the following formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”).
In formula (a1-4),
R ^a32 is an alkyl group having 1 to 6 carbon atoms (haloalkyl group) which may have a halogen atom.
Represents a hydrogen atom or a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents a single bond or an aliphatic hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group is a halogen atom, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, carbon It may be substituted with an acyl group having 2 to 4 carbon atoms and an acyloxy group having 2 to 4 carbon atoms. Specific examples of the substituents shown here include those already exemplified in the range where the carbon number is the upper limit of each. The aliphatic hydrocarbon group for X ^a2 is preferably a chain hydrocarbon group, and more preferably an alkyl group. The methylene group constituting the aliphatic hydrocarbon group is an oxygen atom, a sulfur atom,
A carbonyl group, a sulfonyl group, or a group represented by —N (R ^c ) — may be substituted. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 is a hydrocarbon group having 1 to 18 carbon atoms, preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and these hydrocarbons The group may have a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms. Good.

Of the “alkyl group ^optionally having a halogen atom” for R ^a32 , specific examples of the alkyl group include those already exemplified in the range of 1 to 6 carbon atoms. As the haloalkyl group, a part or all of the hydrogen atoms constituting the alkyl group are substituted with halogen atoms. Specific examples of the haloalkyl group include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group, perfluoropentyl group, perfluorohexyl. Group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like.
Specific examples of the halogen atom, alkoxy group and acyl group for R ^a32 and R ^a33 include those already exemplified.
Hydrocarbon group R ^a34 and R ^a35 are chain hydrocarbon groups may be either an alicyclic hydrocarbon group and aromatic hydrocarbon group. Specific examples thereof include those already exemplified in each carbon number range. Among these, as the chain hydrocarbon group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group are preferable. As the formula hydrocarbon group, a cyclohexyl group,
An adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group and an isobornyl group are preferred. The aromatic hydrocarbon group is phenyl group, naphthyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, anthryl. Group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-
Ethylphenyl is preferred.

When R ^a32 and R ^a33 are alkyl groups, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is particularly preferable.
As the alkoxy group for R ^a33 , a methoxy group and an ethoxy group are more preferable, and a methoxy group is particularly preferable.

As described above, X ^a2 and Y ^a3 may have a hydrogen atom contained therein substituted by a substituent such as a halogen atom or a hydroxy group, but when a hydrogen atom is substituted in this way, The substituent is preferably a hydroxy group.

Examples of the monomer (a1-4) include the following monomers.

In the monomer (a1-4) shown here, a partial structure V ′ shown below can be replaced by a partial structure P ′ shown below as a specific example of the monomer (a1-4).

When the resin (A2) has a structural unit derived from the monomer (a1-4), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A2). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

As the monomer having an acid labile group (2), for example, a monomer represented by the formula (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) can also be used.
In formula (a1-5),
R ³¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
L ^{1 to} L ³ represent an oxygen atom, a sulfur atom, or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—. Here, k1 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group contained in the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

R ³¹ is preferably a hydrogen atom or a methyl group.
L ¹ is preferably an oxygen atom.
L ² and L ³ are each independently an oxygen atom or a sulfur atom. One of L ² and L ³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group. Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

Examples of the monomer (a1-5) include the following monomers. Here, specific examples in which R ³¹ is a methyl group will be shown, but those in which this methyl group is replaced with a hydrogen atom are also specific examples of the monomer (a1-5).

When the resin (A2) has a structural unit derived from the monomer (a1-5), the content ratio is in the range of 10 to 95 mol% with respect to the total structural unit (100 mol%) of the resin (A2). Is preferable, the range of 15-90 mol% is more preferable, and the range of 20-85 mol% is further more preferable.

Since the resin (A2) has the structural unit (ab), if the resin (A2) sufficiently satisfies the requirements (2) and (3) by the action of the structural unit (ab), Structural unit (A
2) may not have such other structural unit (a1). Further, the resin (A1) may have another structural unit (a1) shown here. In this case, the resin (A1) may also have the same characteristics as the resin (A2) characteristics.

<Acid stable structural unit>
The resin (A2) contained in the resist composition preferably has a structural unit having no acid labile group (hereinafter sometimes referred to as “acid-stable structural unit”). As described above, the resin (A1) may have an acid stable structural unit in addition to the structural unit (aa) and the structural unit (ab).

When the resin (A2) has an acid stable structural unit, based on the content ratio of the structural unit (a1) [the total of the structural unit (ab) and the structural unit (a1) other than the structural unit (ab)], The content ratio of the acid stable structural unit may be determined. The ratio of the content ratio of the structural unit (a1) and the content ratio of the acid-stable structural unit is represented by [structural unit (a1)] / [acid-stable structural unit], and preferably 10 to 80 mol% / 90 to 20 mol%, more preferably 20-60 mol% / 80-
40 mol%. In addition, the structural unit (ab) and the structural unit (ab) included in the resin (A2)
Any of the structural units other than (a1) is preferably a structural unit having an adamantane ring, in particular, the structural unit (a1-1). In this case, the total amount of structural units (a1) of the resin (A2) (100 The proportion of the structural unit (a1-1) is preferably 15 mol% or more with respect to (mol%). If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from this resist composition containing this resin (A2) to become more favorable.

The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. An acid stable structural unit having a hydroxy group (hereinafter, referred to as “acid stable structural unit (a2)”).
) And / or the acid-stable structural unit having a lactone ring (hereinafter sometimes referred to as “acid-stable structural unit (a3)”), the resin (A) is as described above for the resin (A1). The coating film or the composition layer easily exhibits excellent adhesion with the substrate. Therefore, this resist composition can produce a resist pattern with good resolution. In addition, the manufacturing method of the resist pattern using this resist composition here is mentioned later. First, an acid stable structural unit (a2) and an acid stable structural unit (a3) suitable as an acid stable structural unit
Will be described with specific examples. In the following description, resin (A1) and resin (A
2) may be collectively referred to as “resin (A)”.

<Acid stable structural unit (a2)>
This resist composition was mixed with KrF excimer laser (wavelength: 248 nm), electron beam or E
When using high energy rays such as UV light for exposure, as the acid stable structural unit (a2),
It is preferable to introduce an acid stable structural unit (a2-0) having a phenolic hydroxy group into the resin (A). When using exposure using a short wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, an acid stable structural unit represented by the formula (a2-1) described later is used as a resin ( It is preferable to introduce into A). Thus, each of the acid stable structural units (a2) possessed by the resin (A) can be selected according to the exposure source used for producing the resist pattern, but the acid stable structural units possessed by the resin (A) ( a2) may have only one type of acid stable structural unit (a2) suitable for the type of exposure source, and two or more types of acid stable structural unit (a2) suitable for the type of exposure source. Or an acid stable structural unit (a2) suitable for the type of exposure source and a combination of other acid stable structural units (a2).

<Acid stable structural unit (a2-1)>
The acid stable structural unit (a2-1) is a structural unit represented by the following formula (a2-1) (hereinafter referred to as “
It may be referred to as “acid stable structural unit (a2-1)”. ).
In formula (a2-1),
L ^a3 represents an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7), and * represents a bond with a carbonyl group (—CO—). Represent.
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.

L ^a3 is preferably an oxygen atom or —O— (CH ₂ ) _k2 — in which k2 is an integer of 1 to 4.
A group represented by CO—O—, and more preferably an oxygen atom or —O—CH ₂ —CO—.
O-, more preferably an oxygen atom.
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 structural unit (a2-1), the following are mentioned, for example.

An acid stable structural unit represented by any one of formula (a2-1-1) to formula (a2-1-17) (a
In the specific example of 2-1), in the same manner as the specific example of the structural unit (aa), those in which the partial structure M is replaced with the partial structure A can also be given as specific examples of the acid stable structural unit (a2-1). .

Among the exemplified acid stable structural units (a2-1), the formula (a2-1-1) and the formula (a2-1-1-
2) Acid stable structural unit (a2-1) represented by any one of formula (a2-1-13) and formula (a2-1-15), and a portion of these acid stable structural units (a2-1) Structure M is partial structure A
In which the formula (a2-1-1), the formula (a2-1-2), the formula (a2-
1-13) and an acid stable structural unit (a2-1) represented by any one of formulas (a2-1-15)
Is more preferable. Resin (A) which has these acid stable structural units (a2-1) is 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate or (meth) Acrylic acid 1- (3,5-dihydroxyadamantan-1-yloxycarbonyl) methyl or the like may be used as a monomer.

When resin (A2) has an acid stable structural unit (a2-1), the content rate is resin (
A2) is selected from a range of 3 to 40 mol% with respect to all structural units (100 mol%),
The range of 35 mol% is more preferable, and the range of 5 to 30 mol% is more preferable.
When the resin (A1) has an acid stable structural unit (a2-1), the total of the structural unit and the structural unit (aa) selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2) The content ratio of the acid stable structural unit (a2-1) may be appropriately adjusted in consideration of the content ratio.

<Acid stable structural unit (a2-0)>
Examples of the acid stable structural unit (a2) include a structural unit represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).
In formula (a2-0),
R ^a30 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same or different.

Specific examples of the alkyl group and a halogen atom having 1 to 6 halogen atoms carbon atoms which may have a R ^a30 are the same as those exemplified in R ^a32 of formula (a1-4). Of these, R ^a30 is
An alkyl group having 1 to 4 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.
Examples of the alkoxy group for R ^a31 include those already exemplified. Of these, R ^a31 is
An alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is particularly preferable.
As the alkyl group for R ^a31 , an alkyl group having 1 to 4 carbon atoms is preferable.
Are more preferable, and a methyl group is particularly preferable.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

Monomer deriving acid stable structural unit (a2-0) (hereinafter referred to as “acid stable monomer (a2-0)
) ". Examples of () include the following.
In the specific example illustrated here, a methyl group or an ethyl group bonded to the benzene ring is represented by R
What substituted by the other substituent illustrated as ^a31 is also a specific example of an acid stable monomer (a2-0).

When the resin (A) is produced using the acid stable monomer (a2-0), the acid stable monomer (
A monomer in which the phenolic hydroxy group in a2-0) is protected with a protecting group can also be used. As the protecting group, for example, a protecting group capable of leaving with an acid or a base is preferable.
A phenolic hydroxy group protected with a protecting group capable of leaving with an acid or a base can be deprotected by contact with an acid or a base. However, since the resin (A) has a structural unit (a1) containing an acid labile group, when the phenolic hydroxy group protected with a protecting group is deprotected, the structural unit (a1) Deprotection by contact with a base is preferred so that the acid labile group is not significantly impaired. As the protecting group, for example, an acetyl group, a benzoyl group and the like are preferable. Examples of the base include 4-dimethylaminopyridine, triethylamine and the like.

Of these, 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is preferable as the acid-stable monomer (a2-0).

When resin (A2) has an acid stable structural unit (a2-0), the content rate is resin (
A) is selected from a range of 5 to 95 mol% with respect to all structural units (100 mol%), 10 to 10
The range of 80 mol% is more preferable, and the range of 15 to 80 mol% is more preferable.
When the resin (A1) has an acid stable structural unit (a2-0), the content ratio may be determined as described for the acid stable structural unit (a2-1).

<Acid stable structural unit (a3)>
The lactone ring contained in the acid stable structural unit (a3) is, for example, a β-propiolactone ring, γ-
A monocyclic ring such as a butyrolactone ring and a δ-valerolactone ring may be used, or a condensed ring of a monocyclic lactone ring and another ring may be used. Among these lactone rings, γ-butyrolactone ring and γ
-A condensed ring of a butyrolactone ring and another ring is preferable.

The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) is referred to as“ acid-stable structural unit (a3-3) ”.
[In the formula (a3-1),
L ^a4 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
p1 represents an integer of 0 to 5.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when p1 is 2 or more, a plurality of R ^a21 may be the same or different.
In formula (a3-2),
L ^a5 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
q1 represents an integer of 0 to 3.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, q1
Is 2 or more, the plurality of R ^a22 may be the same or different.
In formula (a3-3),
L ^a6 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
r1 represents an integer of 0 to 3.
R ^a23 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms;
Is 2 or more, the plurality of R ^a23 may be the same or different. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 each independently represent an oxygen atom or * —O— (CH ₂ ) _k3 —CO in which k3 is an integer of 1 to 4. A group represented by —O— is preferable, an oxygen atom or * —O—CH ₂ —CO—O— is more preferable, and an oxygen atom is more preferable.
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, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1.

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

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

Acid stable structural unit having a condensed ring of γ-butyrolactone ring and cyclohexane ring (a3-
Examples of 3) include the following.
Acid stable structural unit (a) represented by any of formula (a3-1-1) to formula (a3-1-11)
3-1), an acid stable structural unit (a3-2) represented by any one of formulas (a3-2-1) to (a3-2-11) and formulas (a3-3-1) to ( In the acid stable structural unit (a3-3) represented by any one of a3-3-6), as in the case of the structural unit (aa), the partial structure M may be replaced with the partial structure A. Stable structural unit (a3-1), acid stable structural unit (a3
-2) and specific examples of the acid stable structural unit (a3-3). Moreover, in this illustration, those having a methyl group as an example of the substituent (R ^{a21 to} R ^a23 ) of the lactone ring are also exemplified, but those in which this methyl group is replaced with the above-described groups are also acid stable structural units ( a
It is mentioned as a specific example of 3).

Among the acid stable structural units (a3), α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α -(Meth) acryloyloxy-α-methyl-γ-butyrolactone, β- (meth) acryloyloxy-α-methyl-γ-butyrolactone, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1 .0 ^3,7]
Nonan-2-yl, tetrahydro-2-oxo-3-furyl (meth) acrylate and 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] (meth) acrylic acid An acid stable structural unit (a3) derived from nonan-2-yloxy) -2-oxoethyl or the like is preferable.

The resin (A2) has an acid stable structural unit (a3) selected from the group consisting of an acid stable structural unit (a3-1), an acid stable structural unit (a3-2), and an acid stable structural unit (a3-3). If
The total content is preferably in the range of 5 to 70 mol%, more preferably in the range of 10 to 65 mol%, and more preferably 10 to 60 mol% with respect to all the structural units (100 mol%) of the resin (A). A range is further preferred. The content of each of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) is the total structural unit (100
The range of 5 to 60 mol% is preferable, the range of 10 to 55 mol% is more preferable, the range of 20 to 50 mol% is more preferable, and the range of 20 to 45 mol% is more preferable.
When the resin (A1) has an acid stable structural unit (a3) selected from the above group, the content ratio may be determined as described for the acid stable structural unit (a2-1).

<Acid stable monomer (a4)>
Other acid stable structural units will be shown by listing monomers (acid stable monomers) from which other acid stable structural units are derived. In the following description, a monomer for deriving another acid stable structural unit is referred to as “acid stable monomer (a4)”.

As the acid stable monomer (a4), maleic anhydride represented by the following formula (a4-1), itaconic anhydride represented by the formula (a4-2), and formula (a4-3) An acid-stable monomer having a norbornene ring (hereinafter, referred to as “acid-stable monomer (a4-3)”).
) And the like.
[In the formula (a4-3),
Each of R ^a25 and R ^a26 independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms which may have a hydroxy group, a cyano group, a carboxy group, or —COOR ^a27 [R ^a27 has 1 carbon atom;
The methylene group which represents the aliphatic hydrocarbon group of -18, and comprises this aliphatic hydrocarbon group may be replaced by the oxygen atom or the carbonyl group. However, those in which —COOR ^a27 is an acid labile group are excluded (that is, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—).]
Or R ^a25 and R ^a26 combine to form —CO—O—CO—. ]

In R ^a25 and R ^a26 in formula (a4-3), the alkyl group which may have a hydroxy group is preferably a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, a 2-hydroxyethyl group, or the like.
The aliphatic hydrocarbon group for R ^a27 is preferably an alkyl group having 1 to 8 carbon atoms and 4 to 1 carbon atoms.
8 is an alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms and 4 to 4 carbon atoms.
12 alicyclic hydrocarbon groups, and a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, a 2-oxo-oxolan-4-yl group, and the like are more preferable.

Examples of the acid stable monomer (a4-3) include 2-norbornene and 2-hydroxy-
5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, 2-hydroxy-1-ethyl 5-norbornene-2-carboxylate, 5-norbornene-2-methanol and 5-norbornene Examples include -2,3-dicarboxylic acid anhydride.

The resin (A2) is a structural unit derived from maleic anhydride represented by the formula (a4-1):
When it has a structural unit selected from the group consisting of a structural unit derived from itaconic anhydride represented by a4-2) and a structural unit derived from the monomer (a4-3), the total content thereof is the resin (A2). A range of 2 to 40 mol% is preferable with respect to all structural units (100 mol%) of
The range of 3-30 mol% is more preferable, and the range of 5-20 mol% is more preferable.
Resin (A1) is a structural unit derived from maleic anhydride represented by the formula (a4-1):
When it has a structural unit selected from the group consisting of the structural unit derived from itaconic anhydride represented by a4-2) and the structural unit derived from the monomer (a4-3), its content is determined by the acid stable structural unit ( Although it may be determined as described in a2-1), preferably the resin (A1)
The range of 5-20 mol% is preferable with respect to all the structural units (100 mol%).

Furthermore, examples of the acid stable monomer (a4) include those having a sultone ring represented by the formula (a4-4) (hereinafter may be referred to as “acid stable monomer (a4-4)”). .
[In the formula (a4-4),
L ^a7 represents an oxygen atom or ^* -T— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7. T is an oxygen atom or NH), and * represents a carbonyl group Represents the bond hand.
R ^a28 represents a hydrogen atom or a methyl group.
W ¹⁰ represents a sultone ring group which may have a substituent. ]

The sultone ring contained in the sultone ring group is one in which one of two adjacent methylene groups in the methylene group constituting the alicyclic hydrocarbon is replaced by an oxygen atom and the other is a sulfonyl group. Things. A typical example of the sultone ring group is one in which one of the hydrogen atoms in the sultone ring shown below is replaced with a bond, and in the formula (a4-4), the bond with L ^a7 corresponds.
The sultone ring group which may have a substituent is a group in which a hydrogen atom other than a hydrogen atom replaced with the above-described bond is further substituted with a substituent (a monovalent group other than a hydrogen atom). As the substituent, a hydroxy group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, A C1-C7 alkoxycarbonyl group, a C1-C7 acyl group, or a C1-C8 acyloxy group is mentioned.

Specific examples of the acid stable monomer (a4-4) are shown below.

In the above monomer, a structural unit in which a methyl group corresponding to R ^a28 is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-4).

When the resin (A2) has a structural unit derived from the acid-stable monomer (a4-4), the content is 2 to 40 mol% with respect to the total structural unit (100 mol%) of the resin (A2). The range is preferably 3 to 35 mol%, more preferably 5 to 30 mol%.
When the resin (A1) has a structural unit derived from the acid stable monomer (a4-4), the content ratio may be determined as described for the acid stable structural unit (a2-1), but preferably Is preferably in the range of 5 to 30 mol% with respect to all the structural units of the resin (A1).

In addition, as the acid stable monomer (a4), for example, a monomer having a fluorine atom as shown below [hereinafter referred to as “acid stable monomer (a4-5)” may be used. ] Can also be used.

Among such acid stable monomers (a4-5), 5- (3,3,3-trifluoro-2-hydroxy-2- (meth) acrylic acid having a monocyclic or polycyclic aliphatic ring [Trifluoromethyl] propyl) bicyclo [2.2.1] hept-2-yl, 6- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl (meth) acrylate ) Bicyclo [2.2.1] hept-2-yl, 4,4-bis (trifluoromethyl) -3-oxatricyclo [4.2.1.0 ^2,5 ] nonyl (meth) acrylate preferable.

When the resin (A2) has a structural unit derived from the acid-stable monomer (a4-5), the total content is 1 to 20 mol relative to the total structural unit (100 mol%) of the resin (A2). %
The range is preferably 2 to 15 mol%, more preferably 3 to 10 mol%.
When the resin (A1) has a structural unit derived from the acid stable monomer (a4-5), the content ratio may be determined as described for the acid stable structural unit (a2-1). Is preferably in the range of 5 to 40 mol% with respect to all structural units of the resin (A1).

For the production of the resin (A), an acid-stable monomer having a group represented by the following formula (3) (a
The structural unit derived from 4) can also be contained.

First, an acid-stable monomer (a4) having a group represented by the formula (3) [hereinafter, an acid-stable monomer (a4) having a group represented by the formula (3) is sometimes referred to as “acid-stable monomer (a4- 6) "
That's it. ] Is shown. The groups represented by formula (3) are as follows.
[In Formula (3), R ¹⁰ represents a fluorinated alkyl group having 1 to 6 carbon atoms. * Represents a bond. ]

Examples of the fluorinated alkyl group for R ¹⁰ include a difluoromethyl group, a trifluoromethyl group, 1,
1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2
, 2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group,
1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group Perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2-
(Perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5 5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1, 1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2
, 3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group, and perfluorohexyl group.

The fluorinated alkyl group for R ¹⁰ preferably has 1 to 4 carbon atoms, more preferably a trifluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group, and particularly preferably a trifluoromethyl group.

As an acid stable monomer (a4-6), what is represented by the following is mentioned, for example.
In the specific examples of the acid-stable monomer (a4-6) shown here, those in which the following partial structure M ′ is replaced with the partial structure A ′ can also be given as specific examples of the acid-stable monomer (a4-6). .

Moreover, the following can also be mentioned as an acid stable monomer (a4-6).

When the resin (A2) has a structural unit derived from the acid-stable monomer (a4-6), the content ratio is preferably in the range of 5 to 90 mol% with respect to all the structural units of the resin (A2). 1
The range of 0-80 mol% is more preferable, and the range of 20-70 mol% is more preferable.
When the resin (A1) has a structural unit derived from the acid stable monomer (a4-6), the content ratio may be determined as described in the acid stable structural unit (a2-1). Is preferably in the range of 20 to 70 mol% with respect to all the structural units of the resin (A1).

The resin (A) can contain a structural unit derived from the acid stable monomer (a4) having a group represented by the following formula (4).
[In Formula (4),
R ¹¹ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent.
R ¹² represents an optionally substituted hydrocarbon group having 1 to 12 carbon atoms, and the hydrocarbon group is
Hetero atoms may be included.
A ³ is a single bond, — (CH ₂ ) _{m 10} —SO ₂ —O— * or — (CH ₂ ) _{m 10} —CO—O.
Methylene group which represents-* and constitutes the alkylene chain [— (CH ₂ ) _m10 —] shown here is
An oxygen atom, a carbonyl group or a sulfonyl group may be substituted, and a hydrogen atom contained in the alkylene chain may be substituted with a fluorine atom.
m10 represents an integer of 1 to 12. ]

Specific examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms in R ¹¹ include those already exemplified in this range. When these aromatic hydrocarbon groups have a substituent, the substituent is an alkyl group having 1 to 4 carbon atoms, a halogen atom, a phenyl group, a nitro group, a cyano group,
A hydroxy group, a phenyloxy group, a tert-butylphenyl group, and the like.

Examples of R ¹¹ include the following groups. Note that * is a bond with a carbon atom.

The hydrocarbon group having 1 to ¹² carbon atoms in R ¹² may be any of a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
The aliphatic hydrocarbon group is typically an alkyl group, and specific examples thereof have 1 to 1 carbon atoms.
In the range of 12, includes those already exemplified. Examples of the alicyclic hydrocarbon group include those already exemplified in the range of 12 or less carbon atoms.
In addition, when R < ¹² > is an aliphatic hydrocarbon group, this aliphatic hydrocarbon group may contain the hetero atom. The hetero atom is a halogen atom, a sulfur atom, an oxygen atom, a nitrogen atom or the like [a sulfonyl group or a carbonyl group may be included as a linking group].
Examples of R ¹² containing such a heteroatom include the following groups.

When R ¹² is an aromatic hydrocarbon group, specific examples thereof are the same as those for R ¹¹ .

Examples of A ³ include the following groups.

As the acid stable monomer (a4) containing a group represented by the formula (4), for example, the formula (a4-7)
] [Hereinafter referred to as “acid-stable monomer (a4-7)” in some cases. ].

[In the formula (a4-7),
R ¹³ represents a hydrogen atom or a methyl group.
R ¹¹ , R ¹² and A ³ are as defined above. ]

Examples of the acid stable monomer (a4-7) include the following.
In the specific examples of the acid-stable monomer (a4-7) shown here, those obtained by replacing the partial structure M ′ with the partial structure A ′ can also be given as specific examples of the acid-stable monomer (a4-7). .

When the resin (A2) has a structural unit derived from the acid-stable monomer (a4-7), the content is preferably in the range of 5 to 90 mol% with respect to the total structural unit of the resin (A2). 1
The range of 0-80 mol% is preferable, and the range of 20-70 mol% is more preferable.
When the resin (A1) has a structural unit derived from the acid stable monomer (a4-7), the content ratio may be determined as described for the acid stable structural unit (a2-1), but preferably Is preferably in the range of 20 to 70 mol% with respect to all the structural units of the resin (A1).

As the acid stable monomer (a4), a monomer represented by the following formula (a4-8) [hereinafter,
In some cases, it is referred to as “acid-stable monomer (a4-8)”. ] Can also be mentioned.
[In the formula (a4-8),
W ² represents an alicyclic of 3 to 36 carbon atoms.
A ⁴ represents a single bond or an aliphatic hydrocarbon group having 1 to 17 carbon atoms. The methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group, but among A ³ , the atom bonded to the oxygen atom is a carbon atom.
R ¹⁴ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms.
R ¹⁵ and R ¹⁶ each independently represents an alkyl group having 1 to 6 carbon atoms or a haloalkyl group having 1 to 6 carbon atoms. ]

W ² is a monocyclic or polycyclic aliphatic ring having 3 to 36 carbon atoms, and the carbon number thereof is 5 to 18
Is preferable, and the range of 6 to 12 is more preferable. That is, in formula (a4-8)
In the partial structure represented by the formula (KA-1) to (KA-22), one of the hydrogen atoms contained in the alicyclic hydrocarbon in the formula (KA-22) is bonded to A ⁴ and the ring of the alicyclic hydrocarbon is Can be mentioned in which two hydrogen atoms bonded to one of the carbon atoms constituting is replaced with a bond to —O—CO—R ¹⁵ and —O—CO—R ¹⁶ .
The aliphatic ring for W ² is particularly preferably a cyclohexane ring, an adamantane ring, a norbornane ring or a norbornene ring.

Examples of the aliphatic hydrocarbon group for A ⁴ include the alkanediyl groups and divalent alicyclic hydrocarbon groups exemplified above in the range of 17 or less carbon atoms, and those having a carbon number of 17 or less. For example, it may be an aliphatic hydrocarbon group in which an alkanediyl group and an alicyclic hydrocarbon group are combined. Further, the aliphatic hydrocarbon group of A ⁴ may have a substituent.
For example, as an aliphatic hydrocarbon group in which an alkanediyl group and an alicyclic hydrocarbon group are combined, the following formula (X ^x -A), formula (X ^x -B), and formula (X ^x -C) are used. And the group represented.
Where
X ^X1 and X ^X2 each independently have 1 carbon atom which may have a single bond or a substituent.
Represents an alkylene group of ˜6, and X ^X1 and X ^X2 are not single bonds, and the formula (X
^x -A), the total number of carbon atoms of the group represented by the formula ^(X x -B) and formula ^(X x -C) is 17 or less.

Examples of the group in which the methylene group constituting the aliphatic hydrocarbon group for A ⁴ is replaced with an oxygen atom or a carbonyl group include those exemplified for the group (a-1) in the formula (aa).

A ⁴ represents a single bond or * — (CH ₂ ) _s1 —CO—O— (* represents a bond with —O—,
s1 represents the integer of 1-6. Is preferably a group represented by a single bond or * —CH ₂ —.
More preferably, it is CO—O— (* represents a bond with —O—).

Examples of the alkyl group of R ¹⁴ , R ¹⁵ and R ¹⁶ (R ^{14 to} R ¹⁶ ) include those already exemplified in the range of 1 to 6 carbon atoms. As the halogenated alkyl group, an alkyl group having a fluorine atom is particularly preferable. Of the halogenated alkyl groups represented by R ¹⁵ and R ¹⁶ , preferred are a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, etc., among which a perfluoromethyl group,
A perfluoroethyl group and a perfluoropropyl group are mentioned.
R ¹⁴ is preferably a hydrogen atom or a methyl group.

Examples of the acid stable monomer (a4-8) include those shown below. R ^{14 to} R
¹⁶ and A ⁴ are the same as defined above.
Among these,
The acid-stable monomer (a4-8) shown by these is more preferable.

Specific examples of the acid-stable monomer (a4-8) include those represented below.
In the specific examples of the acid-stable monomer (a4-8) shown here, those in which the partial structure M ′ is replaced with the partial structure A ′ as described above are also given as specific examples of the acid-stable monomer (a4-8). .

A preferable acid-stable monomer (a4-8) can be produced, for example, by reacting a compound represented by the formula (a4-8-a) with a compound represented by the formula (a4-8-b). it can. Examples of the compound represented by the formula (a4-8-a) include 1-methacryloyloxy-4-oxoadamantane described in JP-A-2002-226436. Examples of the compound represented by the formula (a4-8-b) include pentafluoropropionic anhydride, heptafluorobutyric anhydride, and trifluoroacetic anhydride.
This reaction is preferably carried out by heating near the boiling point of the compound represented by the formula (a4-8-b) to be used.
[The symbols in formula (a4-8-a) and formula (a4-8-b) all have the same meaning as described above. ]

When the resin (A2) has a structural unit derived from the acid-stable monomer (a4-8), the content ratio is preferably in the range of 5 to 90 mol% with respect to all the structural units of the resin (A2). 1
The range of 0-80 mol% is more preferable, and the range of 20-70 mol% is more preferable.
When the resin (A1) has a structural unit derived from the acid stable monomer (a4-8), the content ratio may be determined as described for the acid stable structural unit (a2-1). Is preferably in the range of 20 to 70 mol% with respect to all the structural units of the resin (A1).

When the resin (A1) has a structural unit derived from the acid stable monomer (a4), the structural unit derived from the acid stable monomer (a4-6) and / or the acid stable monomer (a4-7) is preferable, and the acid stable monomer The structural unit derived from (a4-6) is more preferable.

<Production method of resin>
The resin (A1) can be obtained by polymerizing the compound (aa ′) and a monomer that induces the structural unit (ab). Alternatively, it can be obtained by polymerizing the compound (aa ′), a monomer that induces the structural unit (ab), and a monomer that induces another structural unit (preferably, an acid stable monomer (a4)).
When the resin (A1) is produced, the acid stable monomer (a4) is used as the acid stable monomer (a4).
It is preferable to use 4-6) and / or an acid stable monomer (a4-7). In any case, among the monomers for deriving the structural unit (a1-1) and / or the structural unit (a1-2), those capable of deriving other than the structural unit (ab) may be used. Resin (A1) is
By subjecting such a monomer to a known polymerization method (for example, radical polymerization method), polymerization (
(Copolymerization).

The weight average molecular weight of the resin (A1) is preferably from 6,000 to 80,000,
More preferably from 10,000 to 80,000, even more preferably from 10,000 to 60,000, particularly preferably from 10,000 to 30,000, particularly preferably from 10,000 to 15,000. In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

The resin (A2) can be obtained by polymerizing a monomer that derives the structural unit (ab). Preferably, a monomer derived from the structural unit (ab) is copolymerized with a monomer derived from the acid stable structural unit, and more preferably, the monomer derived from the structural unit (ab) and the acid stable structure. It is obtained by copolymerizing a unit (a2) and / or a monomer that derives an acid stable structural unit (a3).
The resin (A2) includes a structural unit (a1-1) having an adamantyl group and a structural unit (a1-) having a cyclohexyl group as the structural unit (ab) or a structural unit (a1) other than the structural unit (ab). It is preferable to have at least 1 type among 2), and it is more preferable to have the structural unit (a1-1) which has an adamantyl group. As the acid stable structural unit (a2), it is preferable to use a structural unit (a2-1) having a hydroxyadamantyl group.
The acid stable structural unit (a3) includes an acid stable structural unit having a γ-butyrolactone ring (a3).
-1) and an acid stable structural unit having a condensed ring of γ-butyrolactone ring and norbornane ring (
It is preferable to have at least one of a3-2). The resin (A2) can be produced by polymerization (copolymerization) by subjecting the above-described monomer to a known polymerization method (for example, radical polymerization method).

The weight average molecular weight of the resin (A2) is preferably from 2,500 to 50,000,
000 or more and 30,000 or less are more preferable, and 3,000 or more and 10,000 or less are more preferable. In addition, the definition of the weight average molecular weight here and its measuring means are the same as in the case of the resin (A1).

<Acid generator>
The acid generator is classified into a nonionic type and an ionic type. The acid generator (B) contained in the present resist composition may be a nonionic acid generator, an ionic acid generator, or a combination thereof. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 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, a diazonium salt, a phosphonium salt, a sulfonium salt, or an 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 include JP-A 63-26653, JP-A 55-164824,
JP-A-62-269263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,
No. 778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, and the like can be used.
Moreover, what was manufactured by the well-known method can be utilized for an acid generator.

The acid generator contained in the resist composition is preferably an acid generator represented by the following formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). In the following description, among the acid generators (B1), Z ⁺ having a positive charge is referred to as “organic cation”, and a negative charge obtained by removing the organic cation is referred to as “sulfonate anion”. There is.
In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a C 1-17 divalent aliphatic hydrocarbon group which may have a substituent.
The methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced by an oxygen atom, a carbonyl group or a sulfonyl group. May be.
Z ⁺ represents an organic cation.

Specific examples of the perfluoroalkyl group of Q ¹ and Q ² are the alkyl groups already exemplified,
In the alkyl group having 1 to 6 carbon atoms, one in which all of the hydrogen atoms constituting the alkyl group are replaced with fluorine atoms is applicable.
As the acid generator (B1) contained in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1). Q ¹ and Q ²
An acid generator (B1) in which both are fluorine atoms is more preferred.

Specific examples of the aliphatic hydrocarbon group represented by L ^b1 include the removal of two hydrogen atoms from the alkanediyl group already exemplified and the alicyclic hydrocarbons of the above formulas (KA-1) to (KA-22). Group.

Examples of those in which the methylene group constituting the aliphatic hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group include the following formulas (b1-1), (b1-2), and (b1-3) )
, Formula (b1-4), Formula (b1-5) and Formula (b1-6) [Formula (b1-1) to Formula (b1-6)
)] Is exemplified. In addition, Formula (b1-1)-Formula (b1-6) are as follows.
The left and right sides are described in accordance with the formula (B1), and the left bond * is bonded to C (Q ¹ ) (Q ² ), and the right bond * is bonded to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).
In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C 1-15 divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents a divalent aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent a divalent aliphatic hydrocarbon group having 1 to 15 carbon atoms,
These aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent aliphatic hydrocarbon group having 1 to 14 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent a divalent aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
Among these, as the acid generator used in the present resist composition, an acid generator (B1) having a divalent group represented by the formula (b1-1) as L ^b1 is preferable, and L ^b2 is a single bond or The acid generator (B1) having a divalent group represented by the formula (b1-1) which is a methylene group as L ^b1 is more preferable.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4),
More preferably, it is a group represented by any one of formulas (b1-1) to (b1-3).

Here, the specific example of group represented by either of preferable formula (b1-1)-a formula (b1-3) is given. The definition of * is as described above.

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.

Examples of the substituent in the aliphatic hydrocarbon group represented by L ^b1 include a halogen atom, a hydroxy group, a carboxy group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms,
Examples thereof include an acyl group having 2 to 4 carbon atoms and a glycidyloxy group. Specific examples of the halogen atom, aromatic hydrocarbon group, aralkyl group and acyl group are as described above.

Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent. Among the aliphatic hydrocarbon groups, Y is preferably an alkyl group and an alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a carbon number. More preferred are 3-12 alicyclic hydrocarbon groups.
Examples of the substituent in the aliphatic hydrocarbon group of Y include a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, carbon An aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or a group represented by — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 is a carbon number of 1; Represents a hydrocarbon group of ˜16. J2 represents an integer of 0 to 4). The aromatic hydrocarbon group and aralkyl group referred to here may further have, for example, an alkyl group, a halogen atom or a hydroxy group.

The methylene group constituting the aliphatic hydrocarbon group for Y may be replaced with a group (divalent group) selected from the group consisting of an oxygen atom, a sulfonyl group and a carbonyl group. Examples of the group in which the methylene group constituting the alicyclic hydrocarbon group is replaced by an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups constituting the alicyclic hydrocarbon group).
A group in which one is replaced by an oxygen atom), a cyclic ketone group (a group in which one or two methylene groups constituting the alicyclic hydrocarbon group are replaced by a carbonyl group), a sultone ring group (already an acid-stable monomer (a4-4)) ), The two adjacent methylene groups of the methylene groups constituting the alicyclic hydrocarbon group are replaced with oxygen atoms and sulfonyl groups, respectively, and the lactone ring group (alicyclic carbonization). A group in which two adjacent methylene groups in the methylene group constituting the hydrogen group are replaced with an oxygen atom and a carbonyl group, respectively).

Preferred groups of the alicyclic hydrocarbon group of Y are the following formula (Y1), formula (Y2), and formula (Y3
), The formula (Y4) and the formula (Y5), and among these, the formula (Y1), the formula (Y2), the formula (Y3) and the formula (Y5 ) Is more preferable, and an alicyclic hydrocarbon group represented by any one of the formulas (Y1) and (Y2) is particularly preferable. The hydrogen atom constituting these alicyclic hydrocarbon groups may be substituted with a substituent.

Specific examples of the alicyclic hydrocarbon group having a substituent are as follows.

The alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in the formulas (Y1) and (Y2), and when these have a substituent, the substituent is preferably a hydroxy group . That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group is preferable as Y.

Specific examples of the sulfonate anion are specifically shown by the formula (b1-1-1) and the formula (b1-1-1-
2), Formula (b1-1-3), Formula (b1-1-4), Formula (b1-1-5), Formula (b1-1-1)
6), Formula (b1-1-7), Formula (b1-1-8), and Formula (b1-1-9) [hereinafter, “Formula (
b1-1-1) to formula (b1-1-1-9) ". The sulfonate anion represented by this can be mentioned. In the sulfonate anion represented by any one of formulas (b1-1-1) to (b1-1-1-9), L ^b1 is preferably a group represented by formula (b1-1). R ^b2 and R ^b3 are each independently defined as a substituent that may optionally be present in the aliphatic hydrocarbon group of Y, an aliphatic hydrocarbon group having 1 to 4 carbon atoms and a hydroxy group Are preferable, and a methyl group and a hydroxy group are more preferable.

Specific examples of the sulfonate anion represented by any one of the formulas (b1-1-1) to (b1-1-9) include sulfonate anions described in JP 2010-204646 A, for example. be able to.

Hereinafter, as a preferable sulfonate anion, L ^b1 is a group represented by the formula (b1-1), and Y is an alicyclic hydrocarbon group represented by the formula (Y1) or the formula (Y2). A specific example is given.
As the sulfonate anion in which Y is an unsubstituted alicyclic hydrocarbon group, the following formula (b1-s
-1) to any one of formulas (b1-s-9).

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group include those represented by any of the following formulas (b1-s-10) to (b1-s-18). .

As the sulfonate anion in which Y is a cyclic ketone group, the following formula (b1-s-19) to
What is represented by either of formula (b1-s-29) is mentioned.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic group include those represented by any of the following formulas (b1-s-30) to (b1-s-35). It is done.

As the sulfonate anion in which Y is the lactone ring group or the sulfonate ring group,
What is represented by either of the following formula | equation (b1-s-36)-a formula (b1-s-41) is mentioned.

Y may be an alkyl group. Examples of such a sulfonate anion include those represented by the following formula (b1-s-42).

Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include organic onium cations such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, an organic benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and more preferable are the following formulas (b2-1), (b2-2), (b2-3), and (b2-4) [hereinafter, It describes like "Formula (b2-1)-Formula (b2-4)." ] Is an organic cation represented by any of the above. The organic iodonium cation is preferably an organic cation represented by the formula (b2-2).

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group is an alkyl group having 1 to 30 carbon atoms or an alicyclic group having 3 to 18 carbon atoms. A hydrocarbon group and an aromatic hydrocarbon group having 6 to 18 carbon atoms are preferred. The alkyl group is a hydroxy group having 1 to 1 carbon atoms.
May have an alkoxy group having 2 or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group has a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The aromatic hydrocarbon group may be a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. You may have.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
R ^b9 and R ^b10 are each independently an alkyl group having 1 to 18 carbon atoms or 3 to 18 carbon atoms.
Represents an alicyclic hydrocarbon group.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b9 , R ^b10 and R ^b11 are each independently an aliphatic hydrocarbon group, and when the aliphatic hydrocarbon group is an alkyl group, the number of carbon atoms is preferably 1 to 12, and this aliphatic group When the hydrocarbon group is an alicyclic hydrocarbon group, the carbon number is preferably 3 to 18, and 4 to 1
2 is more preferable.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. Among these hydrocarbon groups, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 3 to 18 carbon atoms.
May have an alicyclic hydrocarbon group or an alkylcarbonyloxy group having 1 to 12 carbon atoms.

The combination of R ^b9 and R ^b10 and / or the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3-membered ring to 12-membered ring (preferably a 3-membered ring to 7-membered ring). These 3-membered ring to 12-membered ring (preferably 3-membered ring to 7-membered ring) are an aliphatic ring or a methylene group constituting the aliphatic ring is an oxygen atom, sulfur atom or carbonyl It is a ring that replaces the group.

^{R b13, R b14, R b15} , R b16, R b17 and R ^b18 each independently represent a hydroxy group, an alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
L ^b11 represents an oxygen atom or a sulfur atom.
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 o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 may be the same or different. When s2 is 2 or more, The plurality of R ^b15 may be the same or different, and when t2 is 2 or more, the plurality of R ^b15 may be the same or different.

The alkylcarbonyloxy group for R ^b12 is a group in which the acyl group already exemplified and an oxygen atom are bonded.

^Examples of the alkyl group ^{represented by} R ^{b9 to} R ^b12 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 -An ethylhexyl group etc. are mentioned.
Examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- (adamantane- 1-yl) alkane-1-yl and isobornyl groups.
^As the aromatic hydrocarbon group for R ^b12 , phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group And a naphthyl group.
A group in which an aromatic hydrocarbon group of R ^b12 and an alkyl group are bonded is typically an aralkyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Specific examples of the organic cation represented by the formula (b2-1) to the formula (b2-4) are disclosed in JP 2010-
The thing described in 204646 gazette can be mentioned.

Among the exemplified organic cations, the cation (b2-1) is preferable, and the following formula (b2-
1-1) an organic cation [hereinafter referred to as “cation (b2-1-1)”. ], More preferably, a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 =
x2 = 0. Or tolylsulfonium cation (in formula (b2-1-1), v2
= W2 = x2 = 1, and R ¹⁹ , R ²⁰ and R ²¹ are all methyl groups. Is more preferable.
In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
As this aliphatic hydrocarbon group, a C1-C12 alkyl group and a C4-C18 alicyclic hydrocarbon group are preferable. The aliphatic hydrocarbon group includes, as a substituent, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and 2 carbon atoms.
It may have ˜4 acyl groups or glycidyloxy groups.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, a plurality of R ^b19 may be the same or different. When w2 is 2 or more, a plurality of R ^b20 may be the same or different. When x2 is 2 or more, a plurality of R ^{b19 b21} may be the same or different.
Among these, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (
More preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or 1 carbon atom.
˜12 alkoxy groups.

Here, the specific example of the cation (b2-1-1) which is a suitable organic cation is shown.

Moreover, as an organic cation, the following organic cations can also be mentioned as a suitable thing among the organic cations represented by Formula (b2-3).

The acid generator (B1) has been described for each of the sulfonate anion and the organic cation constituting the acid generator (B1). The acid generator (B1) is a combination of the sulfonate anion and the organic cation. The sulfonate anion and the organic cation can be arbitrarily combined. Table 3 shows combinations of the sulfonate anion and the organic cation. In Table 2, the sulfonate anion represented by the formula (b1-s-1) is represented by the formula number,
An organic cation represented by the formula (b2-c-1), such as “(b1-s-1)”,
According to the formula number, it is expressed as “(b2-c-1)” or the like.

As more preferred acid generator (B1), the following formula (B1-1), formula (B1-2),
Formula (B1-3), Formula (B1-4), Formula (B1-5), Formula (B1-6), Formula (B1-7),
Formula (B1-8), Formula (B1-9), Formula (B1-10), Formula (B1-11), Formula (B1-1)
2), a formula (B1-13), a formula (B1-14), a formula (B1-15), a formula (B1-16), and a formula (B1-17). Among them, the formula (B1-2) and the formula (B1
-3), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula (
What is represented by either B1-13) or (B1-14) is more preferable. In addition, as already described, Y is preferably an alicyclic hydrocarbon group which may have a substituent. Therefore, in this respect, the formula (B1-2), formula (B1-3), (B1- 6), formula (B1-7) and formula (B1)
Those represented by any of -11) are more preferred.

As described above, the acid generator (B) may contain an acid generator different from the acid generator (B1). In this case, the acid generator (B1) in the total amount of the acid generator (B). ) Content is
70 mass% or more is preferable and 90 mass% or more is more preferable. However, it is more preferable that the acid generator (B) in the resist composition of the present invention is substantially only the acid generator (B1).

<Basic compound>
The resist composition may contain a basic compound. The “basic compound” as used herein means a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from the acid generator described above.

The basic compound is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. As the amine, either an aliphatic amine or an aromatic amine may be used. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1).
[In the formula (C1),
R ^c1 , R ^c2 and R ^c3 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. The hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms, and the aromatic hydrocarbon group The hydrogen atom contained is substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It may be. ]

[In the formula (C1-1),
R ^c2 and R ^c3 are as defined above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 may be the same or different. ]

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 is an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or 2 to 2 carbon atoms.
Represents an alkanoyl group of 6;
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 may be the same or different. ]
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

[In Formula (C5) and Formula (C6),
R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3. When o3 is 2 or more, a plurality of R ^c14 is independent, and when p3 is 2 or more, a plurality of R ^c15 are the same or different. It may be.
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

[In Formula (C7) and Formula (C8),
R ^c18, R ^c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represents an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 are independent, and when r3 is 2 or more, the plurality of R ^c19 are the same. However, they may be different, and when s3 is 2 or more, the plurality of R ^c20 may be the same or different.
L ^c2 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —,
-S- or a divalent group in which these are combined is represented. ]

Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine,
Trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine Ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, Ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4 ′
-Diamino-3,3'-dimethyldiphenylmethane and 4,4'-diamino-3,3'-
Diethyldiphenylmethane, etc.
Among these, diisopropylaniline is preferable and 2,6-diisopropylaniline is more preferable.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-
Di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 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′-dipycolylamine, bipyridine, and the like Is mentioned.

As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Examples include ammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

<Solvent>
The resist composition preferably contains a solvent (D). The solvent (D) is applied to the resist composition on the substrate in the production of a resist pattern, which will be described later, according to the type and amount of the resin (A1) to be used and the type and amount of the acid generator. From the viewpoint that the applicability at the time becomes good, an optimum one can be selected as appropriate.

Examples of suitable solvents 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 ethyl pyruvate And esters such as acetone; methyl isobutyl ketone; ketones such as 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. In this resist composition, the solvent may contain only 1 type, and may contain 2 or more types.

<Other ingredients>
The present resist composition may contain other components other than the above-described constituents as necessary. Examples of other components include additives widely used in this technical field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<This resist composition and its preparation method>
This resist composition is a mixture of resin (A) [a combination of resin (A1) and resin (A2)], an acid generator, and a basic compound, a solvent, and other components used as necessary. Can be prepared. In mixing, the order of mixing is arbitrary and is not particularly limited. The temperature at the time of mixing can select a suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to types, such as resin (A1), and resin (A1). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.01 to 0.2 μm.

The content ratio of the resin to the resist composition is preferably 80% by mass to 99% by mass with respect to the total mass of the solid content of the resist composition.
In this specification, what remove | excluded content of the solvent from the mass of this resist composition may be called "solid content" of this resist composition. The content ratio of the solid content to the total mass of the resist composition can be measured by a known analysis means such as liquid chromatography and gas chromatography.

The content of the acid generator is preferably 1 part by mass or more, more preferably 3 parts by mass or more, preferably 30 parts with respect to 100 parts by mass of the resin (A) contained in the resist composition.
The amount is at most 25 parts by mass, more preferably at most 25 parts by mass.

When using a basic compound for this resist composition, the content rate is preferable in it being about 0.01-1 mass% with respect to the total mass of solid content.

As described above, the content of the solvent can be appropriately adjusted according to the type of the resin (A1), but is preferably 90% by mass or more, more preferably 92% by mass or more, based on the total mass of the resist composition. Yes, more preferably 94% by mass or more, preferably 99% by mass or less, more preferably 99.9% by mass or less. In the present resist composition having a solvent content of 90% by mass, the solid content of the present resist composition corresponds to 10% by mass. The present resist composition containing the solvent in such a content ratio is suitable as a thin film resist capable of forming a composition layer having a thickness of about 30 to 300 nm, for example, in a resist pattern manufacturing method described later.

The respective content ratios of these resin (A), acid generator, solvent and basic compound used as necessary can be controlled by the respective amounts used in preparing the resist composition. These content ratios can be obtained by subjecting the prepared resist composition to a known analysis means such as gas chromatography or liquid chromatography.

In addition, when using another component for this resist composition, an appropriate content rate can also be adjusted according to the kind of the said other component.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) a step of applying the resist composition on a substrate;
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used for applying a resist material for semiconductor microfabrication, such as a spin coater. Thus, a coating film made of the present resist composition is formed on the substrate. The film thickness of the coating film can be adjusted by variously adjusting the conditions of the coating apparatus, and by performing appropriate preliminary experiments, the coating conditions are selected so that the coating film has a desired film thickness. Can do. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. The substrate can be washed or an antireflection film can be formed before applying the resist composition. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

In the step (2), the drying is performed by, for example, a heating means using a heating device such as a hot plate (so-called pre-bake), a decompression means using a decompression device, or a combination of these means. The drying conditions are adjusted according to the type of solvent contained in the resist composition. For example, in a heating means using a hot plate, the surface temperature of the hot plate is preferably in the range of about 50 to 200 ° C. . Further, in the decompression means, after enclosing the substrate on which the coating film is formed in an appropriate decompressor, the internal pressure of the decompressor is set to 1 to 1.0 × 10.
^What is necessary is just to make it about ⁵ Pa. Thus, the composition layer is formed on the substrate by removing the solvent from the coating film.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. As an exposure light source for the exposure machine, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (
Those that emit laser light in the ultraviolet region (wavelength of 157 nm), laser light from a solid-state laser light source (such as YAG or semiconductor laser) is wavelength-converted, and harmonic laser light in the far ultraviolet region or vacuum ultraviolet region is emitted. Various things, such as a thing which irradiates a thing, an electron beam, and an ultra-ultraviolet light (EUV), can be used. The exposure machine may be an immersion exposure machine.
As described above, by exposing through a mask, the composition layer has an exposed portion (
An exposed portion) and an unexposed portion (unexposed portion) are generated. In the composition layer of the exposed part, the acid generator contained in the composition layer receives exposure energy to generate an acid, and further, the acid generated by the action of the generated acid [resin (A1) ) And the acid labile group in the structural unit (ab) of the resin (A2) and the acid labile group in the structural unit (a1) of the resin (A2) other than the structural unit (ab)] By doing so, a hydrophilic group is generated, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in the aqueous alkali solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are:
The solubility with respect to aqueous alkali solution will differ remarkably.

In the step (4), a heat treatment (so-called post-exposure baking) for further promoting the progress of the deprotection reaction that may occur in the exposed portion is performed. Such heat treatment is preferably a heating means using a hot plate shown in the step (2). In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. Development here refers to dissolving the composition layer in the exposed area in the aqueous alkaline solution by bringing the heated composition layer into contact with the aqueous alkaline solution,
By leaving the composition layer of the unexposed portion on the substrate, a resist pattern is manufactured on the substrate.
As the alkaline aqueous solution used here, one used in this technical field called “alkaline developer” can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

The resist pattern manufactured on the substrate as described above is preferably rinsed with ultrapure water or the like to further remove moisture remaining on the substrate and the resist pattern.

According to the resist pattern manufacturing method including the steps (1) to (5) as described above, the present resist composition can manufacture a resist pattern having an excellent mask error factor (MEF).

<Application>
The resist composition includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and further immersion exposure It is suitable as a resist composition.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The resin composition ratio (copolymerization ratio of the structural unit derived from each monomer used for resin production to the resin) is obtained by measuring the amount of unreacted monomer in the reaction solution after the completion of polymerization using liquid chromatography. It calculated by calculating | requiring the monomer amount used for superposition | polymerization from the result.
The weight average molecular weight is a value determined by gel permeation chromatography.
The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3 + 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)

Resin Synthesis The compounds (monomers) used in the resin synthesis are shown below.
Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (M-K)”.

Synthesis Example 1 [Synthesis of Resin A1-1]
Monomer (ME) and monomer (MF) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MF)) is 56:44. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, 0.9 mol% and 2.7 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), respectively, as initiators were added with respect to the total monomer amount, and about 5 at 75 ° C. Heated for hours. The resulting reaction mixture is poured into a large amount of n-heptane to precipitate the resin, which is filtered,
Resin A1-1 (copolymer) having a weight average molecular weight of 1.3 × 10 ⁴ was obtained in a yield of 75%. This resin A1-1 has the following structural units. The molar ratio of each structural unit is the structural unit (
u-E) [the structural unit derived from the monomer (ME), depending on the end symbol of its formula number,
It is called “structural unit (u-E)”. The same applies hereinafter. ]: Structural unit (u-F) = 64.9: 35
. 1

Synthesis Example 2 [Synthesis of Resin A1-2]
Monomer (ME) and monomer (MH) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MH)) is 46:54. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-2 (copolymer) having a weight average molecular weight of 1.3 × 10 ^{4 in} a yield of 62%. I got it. This resin A1-2 has the following structural units. The molar ratio of each structural unit was structural unit (u−E): structural unit (u−H) = 59.9: 40.1.

Synthesis Example 3 [Synthesis of Resin A1-3]
Monomer (ME) and monomer (MB) are used as monomers and mixed so that the molar ratio (monomer (ME): monomer (MB)) is 65:35. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-3 (copolymer) having a weight average molecular weight of 1.4 × 10 ^{4 in} a yield of 83%. I got it. This resin A1-3 has the following structural units. The molar ratio of each structural unit was structural unit (u−F): structural unit (u−B) = 65.1: 34.9.

Synthesis Example 4 [Synthesis of Resin A1-4]
Monomers (M-K) and monomers (M-H) are used as the monomers and mixed so that the molar ratio (monomer (ME): monomer (M-H)) is 45:55. An amount of 1.5 mass times dioxane was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.9 mol% and 2.7 mol%, respectively, based on the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of n-heptane to precipitate a resin, and this resin was filtered to obtain a resin A1-5 (copolymer) having a weight average molecular weight of 1.2 × 10 ^{4 in} a yield of 60%. Got in. This resin A1-4 has the following structural units. The molar ratio of each structural unit was structural unit (u-E): structural unit (u-H) = 60.0: 40.0.

Synthesis Example 5 [Synthesis of Resin A2-1]
As the monomer, the monomer (M−H), the monomer (M−I), the monomer (M−G), the monomer (M−J) and the monomer (M−C) are used, and the molar ratio (monomer (M−H)) : Monomer (M-I): monomer (M-J): monomer (MG): monomer (M-C)) were mixed so as to be 50: 5: 4: 33: 8. 1.2 mass times dioxane was added to make a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1.8 mol% and 5.4 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The resulting reaction mixture is
The resin was precipitated by pouring into a large amount of methanol / water mixed solvent, and the resin was filtered. The resin obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and the weight average molecular weight was 4.
7 × 10 ³ resin A2-1 (copolymer) was obtained with a yield of 71%. This resin A2-1 has the following structural units. The molar ratio of each structural unit is as follows: structural unit (uH): structural unit (u-I): structural unit (u-J): structural unit (u-G): structural unit (u-C) = 40. 6
: 5.1: 4.8: 39.7: 9.8.

Synthesis Example 6 [Synthesis of Resin A2-2]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (MG), a monomer (M-J), and a monomer (M-C) are used, and the molar ratio (monomer (MF)). : Monomer (M-I): monomer (M-J): monomer (MG): monomer (M-C)) were mixed so as to be 45: 5: 9: 33: 8. 1.2 mass times dioxane was added to make a solution. To the solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 2.0 mol% and 6.0 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The resulting reaction mixture is
The resin was precipitated by pouring into a large amount of methanol / water mixed solvent, and the resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated, and the resin was filtered twice. 2 × 10 ³ resin A2-2 (copolymer) was obtained with a yield of 80%. This resin A2-2
Has the following structural units. The molar ratio of each structural unit is the structural unit (u-F):
Structural unit (u−J): Structural unit (u−D): Structural unit (u−K): Structural unit (u−C) =
35.2: 5.4: 9.8: 39.8: 9.8.

Synthesis Example 7 [Synthesis of Resin A2-3]
As the monomer, monomer (MB), monomer (MC) and monomer (MD) are used, and the molar ratio (monomer (MB): monomer (MC): monomer (MD) ) Was 35:45:20, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. Into the solution, azobisisobutyronitrile and azobis (2
, 4-dimethylvaleronitrile) is 1.0 mol% and 3.
0 mol% was added and these were heated at 75 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7
. 0 × 10 ³ resin A2-3 (copolymer) was obtained with a yield of 75%. This resin A2-3 has the following structural units. Structural unit (uB): Structural unit (uC): Structural unit (uD) = 34.7: 45.4: 19.9.

Synthesis Example 8 [Synthesis of Resin A3-1]
Monomer (MA) and monomer (MB) are used as monomers, and mixed so that the molar ratio (monomer (MA): monomer (MB)) is 80:20. An amount of 1.5 mass times dioxane was added to prepare a solution. To the solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.5 mol% and 1.5 mol%, respectively, based on the total monomer amount, and these were added at 70 ° C. Heated for about 5 hours. The obtained reaction mixture is poured into a large amount of methanol / water mixed solvent to precipitate the resin,
The resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 8 × 10 ⁴ resin A3-1 (copolymer) was obtained in a yield of 7
Obtained at 0%. This resin A3-1 has the following structural units. Structural unit (u-
A): Structural unit (u−B) = 80.2: 19.8.

Examples 1 to 6 and Comparative Example 1
<Preparation of resist composition>
Resins obtained in Synthesis Examples 1 to 8;
Acid generators B1 to B3 shown below;
Basic compound C1 shown below;
Each was dissolved in a solvent shown below in parts by mass shown in Table 4 and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

Example 1: Structural unit (u-H) corresponds to structural unit (ab) Example 2: Structural unit (u-F) corresponds to structural unit (ab) Example 3: Structural unit (u-H) corresponds to Example 4: Structural unit (ab) corresponds to structural unit (u-H) corresponds to structural unit (ab) Example 5: Structural unit (u-F) corresponds to structural unit (ab) Example 6: Structure Unit (u-H) corresponds to structural unit (ab)

<Acid generator>
B1: Synthesis according to examples of JP 2010-152341 A
B2: synthesized according to examples of WO2008 / 99869
B3: Synthesis according to the example of JP2007-108581

<Basic compound: Quencher>
C1: 2,6-Diisopropylaniline (manufactured by Tokyo Chemical Industry)

<Solvent>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern and its evaluation>
The resist composition of Examples 1 to 6 and the resist composition of Comparative Example 1 were as follows:
Mask error factor (MEF) evaluation by liquid immersion exposure and defect evaluation were performed. Hereinafter, the resist composition and the resist composition of Comparative Example 1 may be collectively referred to as “resist composition”.

<Immersion exposure of resist composition>
The resist composition is subjected to immersion exposure as follows, and a mask error factor (ME
F) Evaluation was carried out.
An organic antireflection film having a thickness of 780 mm is formed by applying a composition for organic antireflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) to a silicon wafer and baking it at 205 ° C. for 60 seconds. Formed. Next, the above resist composition is dried on the organic antireflection film (
Spin coating was performed so that the film thickness after pre-baking was 85 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at the temperature described in the “PB” column of Table 3 for 60 seconds to form a resist film. An ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, on a silicon wafer on which a resist film is formed.
NA = 1.35, 3/4 Annular XY polarized light), contact hole pattern (
Using a mask for forming a hole pitch of 100 nm / hole diameter of 70 nm, exposure was performed while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was post-exposure baked on a hot plate for 60 seconds at the temperature described in the “PEB” column of Table 3. Next, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

In each resist film, the hole diameter of a pattern formed with a mask having a hole diameter of 70 nm is 5
The exposure amount at 5 nm was defined as effective sensitivity.

<Mask error factor (MEF) evaluation>
In effective sensitivity, the hole diameters are 72 nm, 71 nm, 70 nm, 69 nm, and 6 nm, respectively.
The slope of the straight line when the mask hole diameter of a pattern formed with an 8 nm mask was plotted on the horizontal axis and the hole diameter of each pattern on the vertical axis was calculated as MEF. The results are shown in Table 5.

<Defect evaluation>
A 12-inch silicon wafer (substrate) is coated with a resist composition having a dry film thickness of 0.1.
Application (spin coating) was performed to a thickness of 5 μm. After coating, the composition layer was formed on the wafer by pre-baking (PB) for 60 seconds at a temperature shown in the PB column of Table 3 on a direct hot plate.
The wafer on which the composition layer was formed in this manner was subjected to water rinsing for 60 seconds using a developing machine [ACT-12; manufactured by Tokyo Electron Ltd.].
Thereafter, the number of defects on the wafer was measured using a defect inspection apparatus [KLA-2360; manufactured by KLA Tencor]. The results are shown in Table 5.

The resist pattern obtained using this resist composition (Examples 1 to 6) was able to produce a resist pattern having an excellent mask error factor. On the other hand, Comparative Example 1
With this resist composition, the mask error factor of the resulting resist pattern was poor. Moreover, the resist pattern obtained by using this resist composition (Examples 1 to 6) was good in that the number of occurrences of defects was smaller than that of the resist composition of Comparative Example 1.

The resist composition of the present invention can be used for fine processing of semiconductors.

Claims (8)

Resin having a structural unit represented by the formula (aa), structural units of the formula (a1-1) and (ab) (A1),
Table formula (aa) and Formula (aa ') having no structural unit represented by the resin (A1) the same expression as the structure unit of the formula (a1-1) which has (a1-1) which has the structure unit of (ab) being, further comprising a structural unit having an acid labile group different from the acid labile group contained in the structural unit (ab), it is insoluble or poorly soluble in an alkaline aqueous solution, A resin composition (A2) that is soluble in an alkaline aqueous solution by the action of an acid, and a resist composition that contains an acid generator and satisfies the relationship represented by formula (X1).
0.8 <α / β <1.2 (X1)
[In the formula (X1),
α represents the content ratio [mol%] of the structural unit (ab) of the resin (A1) to the total structural unit of the resin (A1).
β represents the content [mol%] of the structural unit having the same structure as the structural unit (ab) of the resin (A2) with respect to all the structural units of the resin (A2). ]
[In the formulas (aa) and (aa ′) ,
R ^aa1 represents a hydrogen atom or a methyl group.
A ^aa1 represents a C1-C6 alkanediyl group which may have a substituent or a group represented by the formula (a-1).
(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. )
R ^aa2 may have a substituent and represents a C 1-18 aliphatic hydrocarbon group in which a fluorine atom is substituted for two or more carbon atoms.
R ^{aa2 ′} represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent. ]
[In the formula (a1-1),
L ^a1 represents an oxygen atom or ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7).
) Represents a group represented by * Is a bond to a carbonyl group.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms. m1 represents the integer of 0-14 . ] The resist composition according to claim 1, wherein A ^{aa1 in the} formula (aa) is an alkanediyl group having 1 to 6 carbon atoms. The resist composition according to claim 1, wherein A ^{aa1 in the} formula (aa) is a methylene group. The resist composition according to claim 1, wherein α and β satisfy a relationship represented by the following formula (X2).
0.9 <α / β <1.1 (X2) The acid generator, a resist composition according to any one of claims 1-4 which is an acid generator represented by the formula (B1).
[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents an ^optionally substituted divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms,
The methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the aliphatic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group. May be.
Z ⁺ represents an organic cation. ] The resist composition according to claim 5, wherein Y in the formula (B1) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. Furthermore, the resist composition in any one of Claims 1-6 containing a solvent. (1) applying the resist composition according to any one of claims 1 to 7 coated on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for producing a resist pattern including: