JP2008274049A - Method of producing resin, resin using the same, positive resist composition and pattern forming method, compound used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing a resin having a narrow constituent distribution with high reproducibility, a resin obtained by the same, a compound used for the same, a resist composition having enhanced performance with regard to sensitivity, LER and pattern collapse, and a method of forming a pattern using the resist composition. <P>SOLUTION: The method of producing the resin having two prescribed repeating units and increasing dissolving rate to an alkali developing liquid by acid action comprises the steps of polymerizing a monomer having a prescribed functional group, and de-protecting the prescribed functional group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a resin. More specifically, a resin suitable for a positive photosensitive composition used in semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystals and thermal heads, and other photofabrication processes, and the use thereof The present invention relates to a pattern forming method and a compound optimal for the resin. More specifically, the present invention relates to a positive photosensitive composition suitable for use as an exposure light source such as far ultraviolet rays of 250 nm or less, preferably 220 nm or less, and an irradiation source using an electron beam, a compound used therefor, and a pattern forming method using the same. Is.

  The chemically amplified photosensitive composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and the acid-catalyzed reaction causes the solubility of the active radiation irradiated area and non-irradiated area in the developer. This is a pattern forming material for changing the pattern to form a pattern on the substrate.

  When a KrF excimer laser is used as an exposure light source, a resin having a basic skeleton of poly (hydroxystyrene) having a small absorption mainly in the 248 nm region is used as a main component. A pattern is formed, which is a better system than the conventional naphthoquinone diazide / novolak resin system.

On the other hand, when a further short wavelength light source, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group exhibits a large absorption in the 193 nm region. It wasn't.
For this reason, a resist for ArF excimer laser containing a resin having an alicyclic hydrocarbon structure has been developed (see, for example, Patent Documents 1 and 2). This resin generally has an acid dissociable group and a lactone group. In order to further increase the functionality, a polar group (such as a hydroxyl group or a carboxyl group) having hydrogen bonding properties such as a hydroxyl group or a carboxyl group may be introduced. However, when monomer species having a polar group having hydrogen bonding properties are copolymerized, the consumption rate of each monomer during polymerization is different, resulting in a large resin composition distribution. When a pattern is formed using this resin, there are problems such as variations in resist pattern width (line edge roughness, LER) and poor sensitivity. As a method for solving this problem, a method in which an acid catalyst is added at the time of polymerization and polymerization is performed while decomposing an acid dissociation group to obtain a carboxyl group-containing resin has been reported (see Patent Document 3 and Patent Document 4). However, since it is difficult to control the decomposition of the acid-dissociable group in this method, it has been very difficult to produce the resin with good reproducibility. Furthermore, since the monomer and the polymer coexist during the polymerization, deprotection under these conditions causes the decomposition of the acid dissociable group of the monomer as well as the acid dissociable group of the polymer, thereby broadening the polymer composition distribution. There was a problem that it was.
JP-A-9-73173 US Pat. No. 6,388,101 JP 2006-316108 A JP 2006-317553 A

  The present invention has been made to solve the problems of the prior art, and is to provide a highly reproducible production method for resins having a narrow composition distribution. Furthermore, it aims at providing the resist composition which improves a sensitivity, LER, and pattern collapse performance drastically with resin manufactured by the method of this invention.

  As a result of intensive studies to achieve the above object, the present inventor has found that the variation in the consumption rate of each monomer during polymerization is reduced by protecting the polar group with a protecting group. Furthermore, by selecting a protecting group, the deprotection step proceeds with high selectivity, and the present invention has been found out that the target resin can be produced with good reproducibility. Furthermore, by performing a deprotection reaction after the polymerization, the progress of deprotection of the acid-decomposable group of the monomer was suppressed, and the composition distribution was succeeded. Further, it has been found that by using the resin produced in the present invention, a resist having particularly improved sensitivity, LER (line edge roughness) and pattern collapse performance can be provided.

  That is, the present invention has the following configuration.

一般式（Ｉ）中、
Ｘａ₁は、水素原子、メチル基、トリフルオロメチル基又はヒドロキシメチル基を表す。
Ｔは単結合又は二価の連結基を表す。
Ｒｘ₁〜Ｒｘ₃は、それぞれ独立にアルキル基またはシクロアルキル基を表す。Ｒｘ₁〜Ｒｘ₃の少なくとも２つが結合して、シクロアルキル基を形成してもよい。
−Ａ−Ｗ （ＩＩ）
一般式（ＩＩ）中、
Ａは酸素原子、−Ｎ（Ｒｗ）−で表される基、又は、硫黄原子を表す。−Ｎ（Ｒｗ）−で表される基においてＮは窒素原子であり、Ｒｗは水素原子、アルキル基又はシクロアルキル基を表す。
ＷはＲｘ₁〜Ｒｘ₃が炭素原子と共に形成する三級アルキル基以外の保護基を表す。
−Ａ−Ｈ （ＩＩＩ）
一般式（ＩＩＩ）中、Ａは一般式（ＩＩ）中のＡと同義である。 <1>
A resin containing a repeating unit represented by the general formula (I) and a repeating unit containing a functional group represented by the general formula (III) and having an increased dissolution rate in an alkaline developer by the action of an acid. A method of manufacturing comprising:
Polymerizing a monomer containing a functional group represented by the general formula (II), and
A deprotection step of converting the functional group represented by the general formula (II) into the functional group represented by the general formula (III) by a deprotection reaction;
Manufacturing method.

In general formula (I),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group. At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group.
-A-W (II)
In general formula (II),
A represents an oxygen atom, a group represented by -N (Rw)-, or a sulfur atom. In the group represented by —N (Rw) —, N is a nitrogen atom, and Rw represents a hydrogen atom, an alkyl group or a cycloalkyl group.
W represents a protecting group other than the tertiary alkyl group formed by Rx ₁ to Rx ₃ together with the carbon atom.
-A-H (III)
In general formula (III), A is synonymous with A in general formula (II).

<2>
The method for producing a resin as described in <1> above, wherein the deprotection step is carried out after completion of the polymerization.

<3>
In the deprotection step, the decomposition rate of the tertiary alkyl group formed by Rx ₁ to Rx ₃ in the general formula (I) together with the carbon atom is 5 mol% or less <1> or <2> The manufacturing method of resin as described in 1 ..

一般式（ＩＶ−１）中、
Ｒ_１及びＲ_２はそれぞれ独立に水素原子、アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基又はアルコキシ基を表す。
Ｒ_３はアルキル基、シクロアルキル基、アルケニル基又はシクロアルケニル基を表す。Ｒ₂とＲ₃とが連結して環を作っても良い。

一般式（ＩＶ−２）中、
Ｒ_４、Ｒ_５及びＲ_６はそれぞれ独立に水素原子、アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基又はアルコキシ基を表す。 <4>
W in general formula (II) is group represented by general formula (IV-1) or general formula (IV-2), The resin in any one of said <1>-<3> characterized by the above-mentioned. Manufacturing method.

In general formula (IV-1),
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group. R ₂ and R ₃ may be linked to form a ring.

In general formula (IV-2),
R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.

<5>
A resin whose dissolution rate in an alkali developer increases by the action of an acid contains a repeating unit having a lactone structure, and the alkali developer by the action of an acid according to any one of the above <1> to <4> For producing a resin in which the dissolution rate with respect to the resin increases.

<6>
A resin whose dissolution rate in an alkaline developer is increased by the action of an acid produced by the method according to any one of <1> to <5> above.

<7>
(A) a compound that generates an acid upon irradiation with an actinic ray or radiation, and
(B) a resin whose dissolution rate in an alkaline developer is increased by the action of the acid described in <6> above,
A positive photosensitive composition comprising:

<8>
A pattern forming method comprising: forming a film from the resist composition according to <7> above, and exposing and developing the film.

一般式（Ｖ）中、
Ｒｖは水素原子、メチル基、トリフルオロメチル基又はヒドロキシメチル基を表す。
Ｒ_４、Ｒ_５及びＲ_６はそれぞれ独立に水素原子、アルキル基、シクロアルキル基、アルケニル基、シクロアルケニル基又はアルコキシ基を表す。
ｎは１〜３の整数を表す。 <9>
A compound represented by formula (V).

In general formula (V),
Rv represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.
n represents an integer of 1 to 3.

  By the production method of the present invention, a resin having a narrow composition distribution can be produced with good reproducibility. Furthermore, sensitivity, line edge roughness, and pattern collapse performance can be improved by a photosensitive composition containing the resin and a pattern forming method using the same.

Hereinafter, the best mode for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

  The present invention contains a repeating unit represented by the general formula (I) and a repeating unit containing a functional group represented by the general formula (III), and has a dissolution rate in an alkaline developer by the action of an acid. A method for producing an increasing resin, a step of polymerizing a monomer containing a functional group represented by the general formula (II), and a deprotection reaction of the functional group represented by the general formula (II) And a deprotection step for converting into a functional group represented by III).

一般式（Ｉ）中、
Ｘａ₁は、水素原子、メチル基、トリフルオロメチル基又はヒドロキシメチル基を表す。
Ｔは単結合又は二価の連結基を表す。
Ｒｘ₁〜Ｒｘ₃は、それぞれ独立にアルキル基、シクロアルキル基を表す。Ｒｘ₁〜Ｒｘ₃の少なくとも２つが結合して、シクロアルキル基を形成してもよい。
−Ａ−Ｗ （ＩＩ）
一般式（ＩＩ）中、
Ａは酸素原子、−Ｎ（Ｒｗ）−で表される基、又は、硫黄原子を表す。−Ｎ（Ｒｗ）−で表される基においてＮは窒素原子であり、Ｒｗは水素原子、アルキル基又はシクロアルキル基を表す。
ＷはＲｘ₁〜Ｒｘ₃が炭素原子と共に形成する三級アルキル基以外の保護基を表す。
−Ａ−Ｈ （ＩＩＩ）
一般式（ＩＩＩ）中、Ａは一般式（ＩＩ）中のＡと同義である。

In general formula (I),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group. At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group.
-A-W (II)
In general formula (II),
A represents an oxygen atom, a group represented by -N (Rw)-, or a sulfur atom. In the group represented by —N (Rw) —, N is a nitrogen atom, and Rw represents a hydrogen atom, an alkyl group or a cycloalkyl group.
W represents a protecting group other than the tertiary alkyl group formed by Rx ₁ to Rx ₃ together with the carbon atom.
-A-H (III)
In general formula (III), A is synonymous with A in general formula (II).

The alkyl group for Rw is preferably an alkyl group having 1 to 10 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, etc.). Can be mentioned.
The cycloalkyl group for Rw is preferably a cycloalkyl group having 3 to 10 carbon atoms (eg, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, etc.). Rw is particularly preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cyclopentyl group, or a cyclohexyl group.
A is particularly preferably an oxygen atom.

The protecting group in W can convert a group having hydrogen bonding properties (group represented by general formula (III)) into a group having no hydrogen bonding properties (group represented by general formula (II)), And it is a protecting group which can be easily deprotected by a deprotecting reaction, and represents a protecting group other than the tertiary alkyl group formed by Rx ₁ to Rx ₃ in the general formula (I) together with the carbon atom. The “protecting group other than the tertiary alkyl group formed by Rx ₁ to Rx ₃ in general formula (I) together with a carbon atom” as used herein means that Rx ₁ to Rx ₃ in general formula (I) are together with a carbon atom. It is a protecting group that does not have the same structure as the tertiary alkyl group to be formed and can be deprotected under the condition that this group does not substantially decompose. The “substantially no decomposition” here refers to the deprotection conditions of the protecting group W, and the decomposition rate of the tertiary alkyl group formed by Rx ₁ to Rx ₃ in the general formula (I) together with the carbon atom (decomposition) The number of moles of tertiary alkyl group / number of moles of tertiary alkyl group before deprotection × 100 (%)) is 10 mol% or less. In particular, it is preferable to use a protecting group that can be deprotected under the condition that the decomposition rate of the tertiary alkyl group is 5 mol% or less. As a method of suppressing the decomposition rate of the tertiary alkyl group to 5 mol% or less, (1) a protective group that can be easily hydrolyzed under acidic conditions at a reaction temperature of 20 ° C. is used for W, and acidic conditions at a reaction temperature of 20 ° C. And a method of selectively hydrolyzing W using (2) a method of using a protective group that can be deprotected by a reaction using a metal for W and deprotecting using a metal. Under these deprotection conditions, the tertiary alkyl group formed by Rx ₁ to Rx ₃ in the general formula (I) together with the carbon atom is not substantially decomposed, so that the decomposition rate can be suppressed to 5 mol% or less. Become.
Such protecting groups include, for example, alkoxymethyl (a group represented by general formula (IV-1)), silyl (a group represented by general formula (IV-2)), triphenylmethyl, methylthiomethyl, and the like. Examples include groups that can be deprotected under relatively mild acidic conditions and groups that can be deprotected under non-acidic conditions such as benzyl and allyl (for example, conditions that can be deprotected by a reaction using a metal). Of these, alkoxymethyl (a group represented by general formula (IV-1)) and silyl (a group represented by general formula (IV-2)) are most preferable.

In general formula (IV-1),
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group. R ₂ and R ₃ may be linked to form a ring.

In general formula (IV-2),
R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.

Although the typical example of the protecting group as W is given to the following, this invention is not limited to this.
In the structural formula, A represents an oxygen atom, NRw (N is a nitrogen atom) and a sulfur atom. R _1w and R _2w each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.

  As an example of the monomer having a protecting group of the general formula (IV-2), a compound represented by the general formula (V) can be given. In addition to the production method of the present invention, this monomer is useful as a raw material for other functional materials (for example, moisture-proof materials, waterproof materials, electrical insulating materials, etc.).

In general formula (V),
Rv represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R _{4, R 5} and _{R 6} have the same meanings as defined in formula (IV-2) _R 4, _{R 5} and _{R 6} in, and particularly preferably an alkyl group having 1 to 5 carbon atoms.
n represents an integer of 1 to 3.

Although the typical example of the monomer which has a protecting group is given, this invention is not limited to this. In the formula, R _3W and R _v represent a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

  The compound represented by the general formula (V) of the present invention can be obtained by a reaction between the compound represented by the general formula (Va) and the compound represented by the general formula (Vb). The reaction is preferably performed at 0 to 80 ° C, and most preferably at 10 to 50 ° C. The compound represented by the general formula (Vb) is preferably used in an amount of 1.0 to 5.0 molar equivalents relative to the hydroxyl group contained in the compound represented by the general formula (Va). Most preferably, molar equivalents are used. The reaction is preferably performed in the presence of a basic substance. Here, the basic substance means a compound having a pKa greater than 7 at 25 ° C. in water. Basic substances include amines (eg, triethylamine, tributylamine, N-methylpiperidine, etc.), nitrogen-containing telocyclic compounds (eg, pyridine, quinoline, picoline, pyrazole, imidazole, 1,2,3-triazole, 1,2 , 4-triazole, tetrazole, etc.) and carbonates (for example, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, etc.), and tertiary amines and nitrogen-containing heterocyclic compounds are particularly preferred. The basic substance is preferably used in an amount of 1.0 to 5.0 molar equivalents, most preferably 1.1 to 2.5 molar equivalents, based on the hydroxyl group contained in the compound represented by the general formula (Va). .

The deprotection process of the present invention will be described. The deprotection step of the present invention may be performed either during polymerization or after polymerization, but it is particularly preferable to perform it after polymerization. This is because when the deprotection reaction is performed during the polymerization, the protective group of the unreacted monomer having the protective group is deprotected, and the effect of the present invention (the monomer consumption rate is uniformized by protecting the monomer having hydrogen bonding properties). This is because (effect) becomes small.
The deprotection reaction is carried out by selecting an optimum deprotection reaction (for example, a deprotection reaction described in Protection Groups 3rd Edition (Time)) according to the protecting group. When the protecting group is an alkoxymethyl group (a group represented by the general formula (III-1)) and a silyl group (a group represented by the general formula (III-2)), an acidic substance and a protic solvent are used. It is preferable to perform a deprotection reaction. The acidic substance here means a compound having a pKa of 4 or less at 25 ° C. in water.

Specific examples of the acidic substance used for the deprotection reaction include sulfonic acid (for example, sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc.), hydrogen halide (hydrogen fluoride, hydrogen chloride, (Hydrogen bromide, hydrogen iodide), perfluorocarboxylic acid (for example, trifluoroacetic acid, perfluorobutanecarboxylic acid, etc.), nitric acid and the like. These acids may be used alone or in combination. Further, it may be a salt of a base such as pyridine (for example, p-toluenesulfonic acid pyridinium salt).
The use amount of the acidic substance is preferably 0.1 to 10 molar equivalents, and most preferably 0.5 to 5 molar equivalents with respect to the protecting group W.
The protic solvent used together with the acidic substance is a solvent having a hydroxyl group, and examples thereof include water and alcohol solvents (for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, etc.).
The deprotection reaction may be performed in a homogeneous solvent system or a heterogeneous solvent system (a two-phase system of an organic solvent containing a resin and a protic solvent). When deprotection is performed in a homogeneous solvent system, it is preferable to add a protic solvent so that the resin does not precipitate. When the deprotection reaction is carried out in a homogeneous solvent system, the protic solvent is preferably used in an amount of 1.0 to 10,000 molar equivalents, and most preferably 10 to 1000 molar equivalents relative to the protective group W. When deprotection is performed in a heterogeneous solvent system, the weight concentration of the acidic substance contained in the protic solvent (the ratio of the acidic substance (g) contained in the acidic aqueous solution (g)) is preferably 20% by weight or less. Most preferred is% by weight or less. Thereby, deprotection reaction can be advanced effectively without decomposing | disassembling the repeating unit which has an acid-decomposable group represented by general formula (I).

The deprotection reaction can be usually carried out at 0 to 100 ° C, preferably 10 to 50 ° C, most preferably 10 to 35 ° C.
The reaction time is preferably within 5 hours, and most preferably within 2 hours.

Examples of the polymerization method of the present invention include addition polymerization such as radical polymerization, cationic polymerization, and ionic polymerization, polycondensation, and the like, and radical polymerization is particularly preferable.
As a radical polymerization method, monomer species and an initiator are dissolved in a solvent, and the polymerization is performed by heating, a polymerization method in which polymerization is performed, or a heating solvent (which may contain a monomer species or an initiator in some cases) And a polymerization method in which the initiator solution is added dropwise over 1 to 10 hours, and the polymerization method is preferred.
Examples of the reaction solvent include ether solvents such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate, dimethylformamide, dimethylacetamide. Examples thereof include amide solvents such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone described below. These solvents may be used alone or in combination. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The polymerization may be performed by adding a chain transfer agent. As the chain transfer agent, a compound containing sulfur is preferable, and a thiol having 1 to 10 carbon atoms and a disulfide having 2 to 20 carbon atoms are most preferable. Examples of the thiol include 1-butanethiol, 1-pentanethiol, cyclohexanethiol, 1-octanethiol and the like. Examples of the disulfide include dibutyl disulfide, dioctyl disulfide, dicyclohexyl disulfide and the like. The addition amount of these chain transfer agents depends on the molecular weight of the target polymer and cannot be determined uniquely, but is generally 0.01 to 10 mol% with respect to the total number of monomer moles. The total monomer concentration in the polymerization reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60 ° C to 100 ° C.

  The resin of the present invention is a resin that decomposes by the action of an acid and increases the solubility in an alkali developer, and decomposes by the action of an acid on the main chain or side chain of the resin, or both the main chain and side chain. A resin having a group that generates an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”) (also referred to as “acid-decomposable resin”, “acid-decomposable resin (B)”, or “resin (B)”) is there.

Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
A preferred group as an acid-decomposable group (acid-decomposable group) is a group obtained by substituting the hydrogen atom of these alkali-soluble groups with a group capable of leaving with an acid.
Examples of the group leaving with an acid include -C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ). ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 and} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The resin (B) of the present invention contains a repeating unit represented by the above formula (I) as an acid-decomposable repeating unit having an acid-decomposable group, but also has an acid-decomposable group having an acid-decomposable group. You may contain a unit.

In formula (I),
Examples of the divalent linking group for T include an alkylene group, -COO-Rt- (Rt is an alkylene group or a cycloalkylene group), -ORt-, and the like. T is particularly preferably a single bond or —COO—Rt—. Rt is preferably an alkylene group having 1 to 5 carbon atoms (—CH ₂ —, — (CH ₂ ) ₃ — and the like).
The alkyl group of Rx _{1 to} Rx ₃ may be linear or branched and has 1 carbon atom such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. ~ 4 are preferred.
The cycloalkyl group represented by Rx _{1 to} Rx ₃ may be monocyclic or polycyclic, and may be a monocyclic cyclic alkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group. A polycyclic cyclic alkyl group such as
Examples of the cycloalkyl group formed by combining at least two of Rx _{1 to} Rx ₃ include a monocyclic cyclic alkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group A polycyclic cyclic alkyl group such as
It is preferable that Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are bonded to bond the above-described cycloalkyl group.

  As for content of an acid-decomposable repeating unit, 20-50 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 25-45 mol%.

Specific examples of the repeating unit having a preferred acid-decomposable group are shown below. In the formula, Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The component (B) preferably contains a repeating unit having a lactone group.
As the lactone group, any group can be used as long as it contains a lactone structure, but a group containing a 5- to 7-membered ring lactone structure is preferred, and a bicyclo structure is added to the 5- to 7-membered ring lactone structure, Those in which other ring structures are condensed to form a spiro structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1) (LC1-4) (LC1-5) (LC1-6) (LC1-13) (LC1-14). By using a specific lactone structure, line edge roughness, Development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. A halogen atom, a hydroxyl group, a cyano group, an acid-decomposable group, etc., more preferably an alkyl group having 1 to 4 carbon atoms, a cyano group, and an acid-decomposable functional group.
n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of Rb ₂ may be the same or different, and a plurality of Rb ₂ may be bonded to form a ring.

  Examples of the repeating unit having a group having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AII). .

In general formula (AII), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.

Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom or a methyl group.

A _b is an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, a single bond, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group obtained by combining these. Represents. Preferably a single bond, -Ab1-CO ₂ - is a linking group represented by.
Ab1 is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexyl group, an adamantyl group, or a norbornyl group.

  V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  The content of the repeating unit having a lactone structure is preferably from 15 to 60 mol%, more preferably from 20 to 50 mol%, still more preferably from 30 to 50 mol%, based on all repeating units in the polymer.

Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto. In the formula, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

  Most preferably, the repeating unit having a lactone group includes the following repeating units. By selecting the optimum lactone structure, the pattern profile and the density dependence become good.

  Component (B) is preferably a repeating unit having a polar group. Examples of the polar group include a hydroxyl group, a cyano group, an amide group, a sulfonamide group, a carbonyl group, an ester group, and a sulfo group, and a hydroxyl group or a cyano group is particularly preferable. This improves the substrate adhesion and developer compatibility. A repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferred. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a preferred hydroxyl group or cyano group, partial structures represented by (VIIa) to (VIId) are preferred.

In general formulas (VIIa) to (VIId), R _{2c to} R _4c each independently represent a hydrogen atom, a hydroxyl group, or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the rest are hydrogen atoms. In (VIIa), more preferably, two of R _{2c to} R _4c are hydroxyl groups and the rest are hydrogen atoms.

  Examples of the repeating unit having a group represented by general formulas (VIIa) to (VIId) include a repeating unit represented by the following general formula (AIII).

In general formulas (AIIIa) to (AIIId), R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
The content of the repeating unit having an alicyclic hydrocarbon structure substituted with a polar group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 mol based on all repeating units in the polymer. %.

  Although the specific example of the repeating unit which has a structure represented by general formula (AIIIa)-(AIIId) is given to the following, this invention is not limited to these.

The resin (B) of the present invention preferably has a repeating unit having an alkali-soluble group. Examples of the alkali-soluble group include a carboxyl group, a sulfonamide group, a sulfonylimide group, a bisulsulfonylimide group, and an aliphatic alcohol in which the α-position is substituted with an electron withdrawing group, and has a repeating unit having a carboxyl group. More preferred. By containing the repeating unit having an alkali-soluble group, the resolution in contact hole applications is increased. The repeating unit having an alkali-soluble group includes a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or an alkali in the main chain of the resin through a linking group. Either a repeating unit to which a soluble group is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is used at the time of polymerization and introduced at the end of the polymer chain, and the linking group is monocyclic or polycyclic. It may have a cyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.
As for content of the repeating unit which has an alkali-soluble group, 1-20 mol% is preferable with respect to all the repeating units in a polymer, More preferably, it is 3-15 mol%, More preferably, it is 5-10 mol%.

  Specific examples of the repeating unit having an alkali-soluble group are shown below.

  The resin (B) of the present invention has, in addition to the above repeating structural units, dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required characteristics of resist, resolving power, heat resistance, sensitivity. Various repeating structural units can be contained for the purpose of adjusting the above.

  Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.

Thereby, the performance required for the resin (B), in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In the resin (B), the content molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and the general required performance of the resist, resolving power, heat resistance, sensitivity. It is set appropriately in order to adjust etc.

When the resin of the present invention is a photosensitive composition and it is a resist composition for ArF exposure, it is preferable that the resin does not have an aromatic group from the viewpoint of transparency to ArF light.
The resin (B) used in the present invention is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units may be methacrylate, all of the repeating units may be acrylate, or a mixture of methacrylate / acrylate, but the acrylate repeating unit is preferably 50 mol% or less of the entire repeating unit.
More preferably, the (meth) acrylate repeating unit having an acid-decomposable group represented by the general formula (I) is 20 to 50%, the (meth) acrylate repeating unit having a lactone structure is 20 to 50%, the general formula (II) A copolymer having 0 to 10% of repeating units having a functional group represented by formula (0) and 0 to 20% of repeating units including a group represented by formula (III). Furthermore, 0 to 20% of (meth) acrylate repeating units having an alicyclic hydrocarbon structure substituted with a polar group other than the repeating unit containing a group represented by formula (III), 0 to 20% of other repeating units. May be included.

  The weight average molecular weight of the resin according to the present invention is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and most preferably 5,000 to 15 in terms of polystyrene by GPC method. , 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented. The molecular weight distribution is usually 1 to 5, preferably 1 to 3, more preferably 1 to 2. The smaller the molecular weight distribution, the better the resolution and the resist shape, and the smoother the side wall of the resist pattern, the better the roughness.

  The resin obtained in the present invention can be suitably used for photosensitive composition applications such as resists. When used as a photosensitive composition, it contains (A) a compound that generates an acid upon irradiation with actinic rays or radiation, and (B) a resin that increases the dissolution rate in the alkaline developer obtained in the present invention. It is preferable to use it as a positive photosensitive composition.

In the photosensitive composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 50 to 99.99% by mass, more preferably 60 to 99.0% by mass in the total solid content. It is.
Moreover, in the photosensitive composition of this invention, resin may be used by 1 type and may be used together two or more.
Hereinafter, each component other than the resin contained in the positive photosensitive composition will be described.

(A) Compound that generates acid upon irradiation with actinic ray or radiation The photosensitive composition of the present invention is a compound (A) that generates acid upon irradiation with actinic ray or radiation (also referred to as an acid generator or a photoacid generator). Containing.
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that may be used in combination and decomposed by irradiation with actinic rays or radiation, preferred compounds include compounds represented by the following general formulas (ZI), (ZII), and (ZIII). it can.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ⁴⁻ , PF ⁶⁻ , SbF ^{6− and the} like. Preferably, it is an organic anion containing a carbon atom.

  Preferable organic anions include organic anions represented by the following formulas AN1 to AN4.

In formulas AN1-AN4,
Rc ₁ represents an organic group.
The organic group for Rc ₁ is preferably an organic group having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality of these is a single bond, —O—, —CO ₂ —, —S—. , —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like.
Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with the bonded alkyl group or aryl group.
The organic group of Rc ₁ is more preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved.
When Rc ₁ has 5 or more carbon atoms, at least one carbon atom is preferably substituted with a hydrogen atom, and more preferably, the number of hydrogen atoms is larger than that of fluorine atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.

The most preferred embodiment of Rc ₁ is a group represented by the following general formula.

Rc ₆ is substituted with a perfluoroalkylene group having 4 or less carbon atoms, more preferably 2 to 4 carbon atoms, more preferably 2 to 3 carbon atoms, or 3 to 5 fluorine atoms and / or 1 to 3 fluoroalkyl groups. Represents a phenylene group.
Ax represents a linking group (preferably a single bond, —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) —). Rd ₁ represents a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.
Rc ₇ represents a hydrogen atom, a fluorine atom, an alkyl group (straight or branched), a cycloalkyl group (monocyclic or polycyclic), an aryl group. The alkyl group, cycloalkyl group and aryl group preferably do not contain a fluorine atom as a substituent.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ and Rc ₅ include the same organic groups as those for Rc ₁ .
Rc ₃ and Rc ₄ may combine to form a ring.
Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group. By combining Rc ₃ and Rc ₄ to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved, which is preferable.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (Z1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  Further preferred examples of the component (Z1) include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group with the remaining being an alkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, and an aryldialkylsulfonium compound.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group and cycloalkyl group that the arylsulfonium compound has as necessary are preferably straight-chain or branched alkyl groups having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and an n-butyl group. , Sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like.
Aryl group R ₂₀₁ to R _203, an alkyl group, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group And may have a phenylthio group as a substituent. Preferred substituents are linear, branched alkyl or cycloalkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, and most preferably alkyl having 1 to 4 carbon atoms. Group, an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, most preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

The 2-oxoalkyl group may be either linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable.
The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c represent a hydrogen atom or an alkyl group.
Rx and Ry each independently represents an alkyl group, an allyl group, or a vinyl group.
Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

The alkyl group and cycloalkyl group as R _{1c to} R _{5c may} be linear, branched, or cyclic, for example, an alkyl group having 1 to 20 carbon atoms, preferably a straight chain having 1 to 12 carbon atoms. Chain and branched alkyl groups (for example, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group), cyclic alkyl groups having 3 to 8 carbon atoms (for example, cyclopentyl) Group, cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably, any one of R _{1c to} R _5c is a linear, branched alkyl group, cycloalkyl group, or a linear, branched, or cyclic alkoxy group, and more preferably the sum of the carbon number of R _1c to R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _5c .
Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an alkyl group which may have an optionally substituted aryl group or a substituent.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
Alkyl group and cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon A cyclic alkyl group (cyclopentyl group, cyclohexyl group, norbornyl group) of several 3 to 10 can be exemplified.
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g. having 6 to 15 carbon atoms), an alkoxy group (for example, 1 to 15 carbon atoms ), Halogen atoms, hydroxyl groups, phenylthio groups, and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (I).

  Of the compounds that decompose upon irradiation with actinic rays or radiation that may be used in combination, preferred compounds further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI). be able to.

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
Alkyl group or a substituted or unsubstituted aryl group of R ₂₀₇ and R ₂₀₈ substituted or unsubstituted, represents an electron-withdrawing group. R ₂₀₇ is preferably a substituted or unsubstituted aryl group.
R ₂₀₈ is preferably an electron withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

Of the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, more preferred are compounds represented by general formulas (ZI) to (ZIII), and even more preferred are compounds represented by (ZI). Most preferred are compounds represented by (ZI-1) to (ZI-3).
Furthermore, a compound that generates an acid corresponding to the above general formula AN1, AN3, AN4, that is, an acid represented by the following formulas AC1, AC3, AC4 by irradiation with actinic rays or radiation is preferable. In the formula, each substituent represents the same meaning as in the general formulas AN1, AN3, and AN4.

That is, the most preferred embodiment of the component (A) is a compound in which X ⁻ is an anion selected from AN1, AN3 and AN4 in the structure of the general formula (ZI).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, examples of particularly preferable compounds are listed below.

  An acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.

  The content of the acid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7% by mass, based on the total solid content of the resist composition. %.

The photosensitive composition of this invention may contain (B2) resin which does not have the group decomposed | disassembled by the effect | action of an acid other than the said acid-decomposable resin.
“No acid-decomposable group” means that there is no or very little decomposability due to the action of acid in an image forming process in which the photosensitive composition of the present application is usually used, and the image is substantially decomposed by acid decomposition. It has no group that contributes to formation. Examples of such a resin include a resin having an alkali-soluble group and a resin having a group that is decomposed by the action of an alkali and improves the solubility in an alkali developer.

The resin (B2) is preferably a resin having at least one repeating unit derived from a (meth) acrylic acid derivative and / or an alicyclic olefin derivative.
As the alkali-soluble group contained in the component (B2), a carboxyl group, a phenolic hydroxyl group, an aliphatic hydroxyl group substituted at the 1- or 2-position with an electron-withdrawing group, or an amino group substituted with an electron-withdrawing group (For example, a sulfonamide group, a sulfonimide group, a bissulfonylimide group), a methylene group substituted with an electron withdrawing group or a methine group (for example, a methylene group substituted with at least two selected from a ketone group and an ester group, Methine group) is preferred.

  The group (b) contained in the component (B2) that decomposes by the action of alkali and increases the solubility in an alkali developer is preferably a lactone group or an acid anhydride group, more preferably a lactone group. (B) Specific examples of the repeating unit having a group that decomposes by the action of an alkali and increases the solubility in an alkali developer include the following repeating units.

  The component (B2) may have a repeating unit having a functional group other than the above. As the repeating unit having another functional group, an appropriate functional group can be introduced in consideration of dry etching resistance, hydrophilicity / hydrophobicity, interaction property and the like.

  Other repeating units include a repeating unit having a polar functional group such as a hydroxyl group, a cyano group, a carbonyl group, and an ester group, a repeating unit having a monocyclic or polycyclic hydrocarbon structure, a silicon atom, a halogen atom, and a fluoroalkyl group. Or a repeating unit having a plurality of these functional groups.

  Specific examples of the preferred component (B2) are shown below.

  The addition amount of the component (B2) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and still more preferably 0 to 15% by mass with respect to the component (B).

(C) A dissolution control compound having a molecular weight of 3000 or less, having at least one selected from an alkali-soluble group, a hydrophilic group and an acid-decomposable group. The photosensitive composition of the present invention comprises an alkali-soluble group, a hydrophilic group and an acid-decomposable group. A dissolution control compound having a molecular weight of 3000 or less (hereinafter also referred to as “component (C)”, “solution control compound”, or “dissolution inhibitor”) having at least one selected from
Examples of the dissolution control compound include a carboxyl group, a sulfonylimide group, a compound having an alkali-soluble group such as a hydroxyl group substituted at the α-position with a fluoroalkyl group, a hydroxyl group, a lactone group, a cyano group, an amide group, a pyrrolidone group, a sulfone group. A compound having a hydrophilic group such as an amide group or a compound containing a group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferable. The group capable of decomposing by the action of an acid to release an alkali-soluble group or a hydrophilic group is preferably a group in which a carboxyl group or a hydroxyl group is protected with an acid-decomposable group. In order not to lower the permeability of 220 nm or less as the dissolution control compound, it is preferable to use a compound that does not contain an aromatic ring, or to use a compound having an aromatic ring in an amount of 20 wt% or less based on the solid content of the composition.
Preferred dissolution control compounds include carboxylic acid compounds having an alicyclic hydrocarbon structure such as adamantane (di) carboxylic acid, norbornane carboxylic acid, and cholic acid, or compounds in which the carboxylic acid is protected with an acid-decomposable group, and polyols such as saccharides. Or a compound having its hydroxyl group protected with an acid-decomposable group is preferred.

  The molecular weight of the dissolution controlling compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution control compound is preferably 3 to 40% by mass, more preferably 5 to 20% by mass, based on the solid content of the photosensitive composition.

  Specific examples of the dissolution control compound are shown below, but the present invention is not limited thereto.

(D) Basic compound The positive photosensitive composition of the present invention comprises (D) a base in order to reduce the change in performance over time from exposure to heating or to control the diffusibility of the acid generated by exposure in the film. It is preferable to contain a functional compound.

  Examples of basic compounds include nitrogen-containing basic compounds and onium salt compounds. Preferable nitrogen-containing basic compound structures include compounds having partial structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbons, a cycloalkyl group having 3 to 20 carbons or an aryl group having 6 to 20 carbons, R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferred compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, hydroxyl groups and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undec-7-ene. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  These basic compounds are used alone or in combination of two or more. The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of a positive photosensitive composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

(E) Fluorine and / or Silicone Surfactant The positive photosensitive composition of the present invention further comprises a fluorine and / or silicon surfactant (fluorine surfactant and silicon surfactant, fluorine atom). Or a surfactant containing both silicon atoms), or preferably two or more.

  When the positive photosensitive composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. A resist pattern with few defects can be provided.

  Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.

  Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of fluorine and / or silicon-based surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive photosensitive composition (excluding the solvent). %.

(H) Organic solvent The photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent.

  Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent containing two or more solvents having different functional groups. As a result, the solubility of the material is increased, and not only the generation of particles over time can be suppressed, but also a good pattern profile can be obtained. Preferable functional groups contained in the solvent include ester groups, lactone groups, hydroxyl groups, ketone groups, and carbonate groups. As the mixed solvent having different functional groups, the following mixed solvents (S1) to (S5) are preferable.
(S1) a mixed solvent obtained by mixing a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group,
(S2) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a ketone structure;
(S3) a mixed solvent obtained by mixing a solvent having an ester structure and a solvent having a lactone structure;
(S4) a mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group;
(S5) A mixed solvent obtained by mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent containing a hydroxyl group.
As a result, the generation of particles during storage of the resist solution can be reduced, and the generation of defects during application can be suppressed.

  Examples of the solvent containing a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Particularly preferred are propylene glycol monomethyl ether and ethyl lactate.

  Examples of the solvent not containing a hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide and the like. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are particularly preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate. 2-heptanone and cyclohexanone are most preferred.

Examples of the solvent having a ketone structure include cyclohexanone and 2-heptanone, and cyclohexanone is preferable.
Examples of the solvent having an ester structure include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, and butyl acetate, and propylene glycol monomethyl ether acetate is preferable.
Examples of the solvent having a lactone structure include γ-butyrolactone.
Examples of the solvent having a carbonate structure include propylene carbonate and ethylene carbonate, with propylene carbonate being preferred.

The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a ketone structure is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 40/60 to 80/20. . A mixed solvent containing 50% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of coating uniformity.
The mixing ratio (mass) of the solvent having an ester structure and the solvent having a lactone structure is 70/30 to 99/1, preferably 80/20 to 99/1, and more preferably 90/10 to 99/1. . A mixed solvent containing 70% by mass or more of a solvent having an ester structure is particularly preferable from the viewpoint of stability over time.
When mixing a solvent having an ester structure, a solvent having a lactone structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a lactone structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.
When mixing a solvent having an ester structure, a solvent having a carbonate structure, and a solvent containing a hydroxyl group, the solvent having an ester structure is 30 to 80% by mass, the solvent having a carbonate structure is 1 to 20% by mass, and the hydroxyl group is contained. It is preferable to contain 10-60 mass% of solvent to do.

A preferable embodiment of these solvents is a solvent containing an alkylene glycol monoalkyl ether carboxylate (preferably propylene glycol monomethyl ether acetate), more preferably a mixed solvent of an alkylene glycol monoalkyl ether carboxylate and another solvent, The other solvent is at least one selected from a functional group selected from a hydroxyl group, a ketone group, a lactone group, an ester group, an ether group and a carbonate group, or a solvent having a plurality of these functional groups. The most preferred mixed solvent is a mixed solvent of propylene glycol monomethyl ether acetate and at least one selected from ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether, butyl acetate, and cyclohexanone.
The development defect performance can be improved by selecting an optimum solvent.

<Other additives>
The positive photosensitive composition of the present invention may further contain a dye, a plasticizer, a surfactant other than the component (E), a photosensitizer, a compound that promotes solubility in a developer, and the like as necessary. It can be included.

  The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.

  A preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the acid-decomposable resin. The amount is preferably 50% by mass or less from the viewpoint of suppressing development residue and preventing pattern deformation during development.

  Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to methods described in, for example, JP-A-4-1222938, JP-A-2-28531, U.S. Pat. No. 4,916,210, European Patent 219294, and the like. Can be easily synthesized.

  Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

In the present invention, a surfactant other than the above (E) fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.
These surfactants may be added alone or in some combination.

(Pattern formation method)
The positive photosensitive composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows. The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

For example, a positive photosensitive composition is coated on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by a suitable coating method such as a spinner or coater, dried, and photosensitive. A film is formed.
The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred. Further, an overcoat layer may be further provided on the photosensitive film so that the immersion medium and the photosensitive film do not come into direct contact with each other during the immersion exposure. Thereby, the elution of the composition from the photosensitive film to the immersion medium is suppressed, and development defects are reduced.
Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ excimer laser, EUV (13 nm) An electron beam is preferred.

In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  EXAMPLES Next, although an Example is given and this invention is further demonstrated, this invention is not limited to these Examples.

(Synthesis Example 1) Synthesis of Resin (RA-1-1) Under a nitrogen stream, 12.3 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., and 8.17 g of the following compound (1-1) ( 48.0 mmol), compound (1-2) 5.67 g (24.0 mmol), compound (1-3) 9.84 g (42.0 mmol), compound (1-4) 0.87 g (6.0 mmol) and A solution prepared by dissolving 1.58 g (9.6 mmol) of a polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 110.5 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. 2 g of the obtained polymerization solution was taken out and added to a mixed solution of 18 mL of methanol and 2 mL of water to precipitate a resin (RA-1). When the sample was collected by filtration and subjected to NMR measurement after drying, it was found that the composition ratio was 41.0 / 21.9 / 33.9 / 3.2 from the left. After allowing to cool, 200 mL of ethyl acetate and 100 mL of 3N hydrochloric acid were added and mixed in a separatory funnel for 5 minutes. At this time, it was confirmed by NMR that the acetal part derived from (1-4) had completely disappeared. After separating the organic phase and the aqueous phase, 100 mL of water was added to the organic phase and mixed for 5 minutes. After separating the organic phase and the aqueous phase, the organic phase was concentrated with an evaporator to remove ethyl acetate, and the obtained organic phase was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 21.2 g of resin (RA-1-1).

(Synthesis Examples 2 and 3) Synthesis of Resin (RA-1-2) and Resin (RA-1-3) Exactly the same operation as in Synthesis Example 1 was repeated to obtain Resin (RA-1-2) and Resin (RA- 1-3) 21.5g and 21.1g were obtained, respectively.

(Synthesis Example 4 (Comparative Example)) Synthesis of Resin (RA-1′-1) 8.17 g (48.0 mmol) of the following Compound (1-1), 5.67 g (24.0 mmol) of Compound (1-2) Compound (1-3) 11.3 g (48.0 mmol) and polymerization initiator V-60 (Wako Pure Chemical Industries, Ltd.) 1.58 g (9.6 mmol) were dissolved in cyclohexanone 110.5 g. 1.0 mL of a sulfuric acid-cyclohexanone solution in which 15 g was dissolved in 100 g of cyclohexanone was added. Under a nitrogen stream, this solution was added dropwise to 12.2 g of cyclohexanone heated to 80 ° C. over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. After allowing to cool, the polymerization solution was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 21.2 g of resin (RA-1′-1).

(Synthesis Examples 5 and 6 (Comparative Example)) Synthesis of Resin (RA-1′-2) and Resin (RA-1′-3) Exactly the same operation as in Synthesis Example 4 was repeated, and the resin (RA-1′- 21.1 g and 22.1 g of the resin (RA-1′-3) were obtained, respectively.

  The weight average molecular weight, dispersion degree, and composition ratio of the resins obtained in Synthesis Examples 1 to 6 are shown in Table 1-1. From Table 1-1, it can be seen that the methods of Synthesis Examples 1 to 3 can produce the resin with higher reproducibility than the methods of Synthesis Examples 4 to 6. Further, by comparing the resin (RA-1) obtained in Synthesis Example 1 and the resin (RA-1-1), a tertiary alkyl group derived from the compound (1-3) (1- It can be seen that the deprotection reaction proceeds without decomposing the methyladamantyl group).

(Synthesis Example 7) Synthesis of Resin (RA-2b) Under a nitrogen stream, 14.8 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., and 10.7 g (48.) of the following compound (2-1) was added thereto. 0 mmol), compound (2-2) 10.1 g (24.0 mmol), compound (2-3) 8.75 g (48.0 mmol) and polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries) 1.58 g (9 .6 mmol) in 132.8 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. 2 g of the obtained polymerization solution was taken out and added to a mixed solution of 18 mL of methanol and 2 mL of water to precipitate a resin (RA-2a). When the sample was collected by filtration and subjected to NMR measurement after drying, it was found that the composition ratio was 40.0 / 20.9 / 39.1 from the left. After allowing to cool, 200 mL of ethyl acetate and 100 mL of 3N hydrochloric acid were added and mixed in a separatory funnel for 5 minutes. After separating the organic phase and the aqueous phase, 100 mL of water was added to the organic phase and mixed for 5 minutes. After separating the organic phase and the aqueous phase, the organic phase was concentrated with an evaporator to remove ethyl acetate, and the obtained organic phase was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 20.1 g of resin (RA-2b) (composition ratio 39.5 / 20.0 / 39.6 from the left).

(Monomer synthesis example) Synthesis of monomer (3-2) 30.3 g (120 mmol) of the following compound (2′-2) and 24.5 g (360 mmol) of imidazole were dissolved in 150 mL of N, N-dimethylacetamide, and tert was added thereto. -45.2 g (300 mmol) of butyldimethylchlorosilane was added and stirred at 25 ° C for 10 hours. Then, ethyl acetate 1000mL and water 500mL were added and liquid separation operation was performed. The organic phase was concentrated with an evaporator and then isolated and purified by column chromatography (filler silica gel (manufactured by Wako Pure Chemical Industries, Ltd.), eluent hexane / ethyl acetate = 10/1). The compound was identified by NMR, and from the results shown below, it was confirmed that the compound had a structure represented by the formula (3-2).

¹ H NMR (solvent heavy dimethyl sulfoxide)
δ 0.08 (12H, s), 0.83 (18H, s), 1.57 (4H, d, J = 1.8 Hz), 1.71 (4H, dd, J = 23.1 Hz, 8.1 Hz) ), 1.83 (3H, s), 1.88 (d, J = 1.8 Hz), 2.02 (4H, dd, J = 8.1 Hz, 23.1 Hz), 2.28 (1 H, m) ), 5.61 (1H, t, J = 1.2 Hz), 5.95 (1H, s)

(Synthesis Example 8) Synthesis of Resin (RA-3b) Under a nitrogen stream, 14.8 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., to which 8.17 g (48. 01.6), Compound (3-2) 11.6 g (24.0 mmol), Compound (2-3) 9.42 g (48.0 mmol) and polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries) 1.58 g (9 .6 mmol) in 133.2 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. 2 g of the obtained polymerization solution was taken out and added to a mixed solution of 18 mL of methanol and 2 mL of water to precipitate a resin (RA-3a). When the sample was collected by filtration and subjected to NMR measurement after drying, it was found that the composition ratio was 40.5 / 20.2 / 39.3 from the left. After allowing to cool, 200 mL of ethyl acetate and 100 mL of 3N hydrochloric acid were added and mixed in a separatory funnel for 5 minutes. After separating the organic phase and the aqueous phase, 100 mL of water was added to the organic phase and mixed for 5 minutes. After separating the organic phase and the aqueous phase, the organic phase was concentrated with an evaporator to remove ethyl acetate, and the obtained organic phase was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 19.2 g of a resin (RA-3b) (composition ratio 39.9 / 20.0 / 40.1 from the left).

(Synthesis Example 9) Synthesis of Resin (RA-4b) Under a nitrogen stream, 16.3 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., and 10.7 g (48.) of the following compound (2-1) was added thereto. 0 mmol), 10.1 g (24.0 mmol) of compound (2-2), 11.0 g (42.0 mmol) of compound (4-3), 0.87 g (6.0 mmol) of compound (4-4) and polymerization initiation A solution prepared by dissolving 1.58 g (9.6 mmol) of Agent V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) in 146.9 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. 2 g was taken out from the obtained polymerization solution and added to a mixed solution of 18 mL of methanol and 2 mL of water to precipitate a resin (RA-4a). When the sample was collected by filtration and subjected to NMR measurement after drying, it was found that the composition ratio was 40.1 / 20.2 / 35.3 / 3.4 from the left. After allowing to cool, 200 mL of ethyl acetate and 100 mL of 3N hydrochloric acid were added and mixed in a separatory funnel for 5 minutes. After separating the organic phase and the aqueous phase, 100 mL of water was added to the organic phase and mixed for 5 minutes. After separating the organic phase and the aqueous phase, the organic phase was concentrated with an evaporator to remove ethyl acetate, and the obtained organic phase was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration, and dried under reduced pressure at 40 ° C. for 24 hours to obtain resin (RA-4b) (composition ratio 39.9 / 20.0 / 35.1 / 5.0 from the left) as 19. 8 g was obtained.

(Synthesis Example 10) Synthesis of Resin (RA-5b) Under a nitrogen stream, 16.3 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., and then 12.2 g (55.55) of the following compound (2-1). 0 mmol), compound (4-3) 14.4 g (55.0 mmol), compound (5-3) 0.88 g (5.0 mmol) and polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries) 1.58 g (9 .6 mmol) in 146.9 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. 2 g was taken out from the obtained polymerization solution and added to a mixed solution of 18 mL of methanol and 2 mL of water to precipitate a resin (RA-5a). The sample was collected by filtration and subjected to NMR measurement after drying, and it was found that the composition ratio was 48.0 / 47.9 / 4.1 from the left. After allowing to cool, the polymerization solution was transferred to an autoclave, 2.0 g of palladium carbon (containing 5% by weight of palladium metal) was added, the pressure was increased to 60 atm, and the mixture was heated at 50 ° C. for 8 hours. After allowing to cool, palladium carbon was removed by filtration. The obtained solution was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 22.5 g of resin (RA-5b) (composition ratio 48.1 / 48.0 / 3.9 from the left).

(Synthesis Example 11 (Comparative Example)) Synthesis of Resin (RA-2 ′) Under a nitrogen stream, 13.1 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C., and the following compound (2-1) 10 0.7 g (48.0 mmol), compound (10-2) 6.06 g (24.0 mmol), compound (2-3) 9.42 g (48.0 mmol) and polymerization initiator V-60 (manufactured by Wako Pure Chemical Industries, Ltd.) A solution prepared by dissolving 1.58 g (9.6 mmol) in 117.7 g of cyclohexanone was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The obtained polymerization solution was dropped into a mixed solution of 900 mL of methanol and 100 mL of water. The precipitated resin was collected by filtration and dried under reduced pressure at 40 ° C. for 24 hours to obtain 22.8 g of resin (RA-2 ′).

  The weight average molecular weight, dispersion degree, and composition ratio of the resins obtained in Synthesis Examples 7 to 10 are shown in Table 1-2.

Examples and Comparative Examples <Condition 1>
<Resist preparation>
The components shown in Table 2 below were dissolved in a solvent to prepare a solution having a solid content concentration of 8% by mass, and this was filtered through a 0.03 micron polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 2.

<Pattern formation method>
An anti-reflective coating DUV-42 manufactured by Brewer Science Co., Ltd. was uniformly applied to 600 angstroms on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, dried on a hot plate at 100 ° C. for 90 seconds, and then at 190 ° C. Heat drying was performed for 240 seconds. Thereafter, each positive resist solution was applied by a spin coater and dried at 120 ° C. for 60 seconds to form a 160 nm resist film.
The resist film was exposed with an ArF excimer laser stepper (NA = 0.75, dipole manufactured by ASML) through a mask, and heated on a hot plate at 120 ° C. for 60 seconds immediately after the exposure. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a line pattern.

<Condition 2>
<Registration adjustment>
The components shown in Table 2 below and the surface hydrophobized resin Polymer-A were dissolved so that the receding contact angle of pure water in the coating film was 70 to 75 ° to prepare a solution having a solid content concentration of 8% by mass. Was filtered through a 0.03 μm polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 2.

<Pattern formation method>
Using an ArF excimer laser immersion scanner (NA = 0.85), and using the same method as resist evaluation 1 except that immersion exposure was performed using ultrapure water as the immersion liquid, a line pattern was obtained. It was.
<Sensitivity>
The exposure amount for reproducing the 80 nm line and space 1/1 mask pattern was determined as the optimum exposure amount (Eopt). The smaller this value, the higher the sensitivity.
<Line edge roughness>
The line edge roughness (LER) is measured by using a length-measuring scanning electron microscope (SEM) to observe an isolated pattern of 80 nm and from the reference line where the edge in the longitudinal direction of the line pattern should be 5 μm. The distance was measured by 50 points with a length measuring SEM (Hitachi, Ltd. S-8840), the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance.
<Pattern collapse>
When the exposure amount that reproduces the 80 nm line and space 1: 1 mask pattern is the optimum exposure amount, the dense pattern of line and space 1: 1 and the isolated pattern of line and space 1:10 are exposed at the optimum exposure amount. Therefore, the line width that resolves the pattern without falling down in a fine mask size is defined as the limit pattern falling line width. The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur.

  The abbreviations in Table 2 are shown below.

[Basic compounds]
DIA: 2,6-diisopropylaniline TEA: triethanolamine PEA: N-phenyldiethanolamine [surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
〔solvent〕
S1: Propylene glycol methyl ether acetate S2: 2-heptanone S3: Cyclohexanone S4: Propylene glycol methyl ether

  From Table 2, it is clear that the positive resist composition of the present invention is excellent in sensitivity, LER (line edge roughness) and pattern collapse performance, and further, the difference between lots due to polymerization is small.

Claims (9)

A resin containing a repeating unit represented by the general formula (I) and a repeating unit containing a functional group represented by the general formula (III) and having an increased dissolution rate in an alkaline developer by the action of an acid. A method of manufacturing comprising:
Polymerizing a monomer containing a functional group represented by the general formula (II), and
A deprotection step of converting the functional group represented by the general formula (II) into the functional group represented by the general formula (III) by a deprotection reaction;
Manufacturing method.

In general formula (I),
Xa ₁ represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
T represents a single bond or a divalent linking group.
Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group. At least two of Rx _{1 to} Rx ₃ may be bonded to form a cycloalkyl group.
-A-W (II)
In general formula (II),
A represents an oxygen atom, a group represented by -N (Rw)-, or a sulfur atom. In the group represented by —N (Rw) —, N is a nitrogen atom, and Rw represents a hydrogen atom, an alkyl group or a cycloalkyl group.
W represents a protecting group other than the tertiary alkyl group formed by Rx ₁ to Rx ₃ together with the carbon atom.
-A-H (III)
In general formula (III), A is synonymous with A in general formula (II).   The method for producing a resin according to claim 1, wherein the deprotection step is performed after completion of the polymerization. _3. The decomposition rate of the tertiary alkyl group formed by Rx ₁ to Rx ₃ in the general formula (I) together with the carbon atom in the deprotection step is 5 mol% or less, according to claim 1 or 2. Manufacturing method of resin. The method for producing a resin according to any one of claims 1 to 3, wherein W in the general formula (II) is a group represented by the general formula (IV-1) or the general formula (IV-2). .

In general formula (IV-1),
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group or a cycloalkenyl group. R ₂ and R ₃ may be linked to form a ring.

In general formula (IV-2),
R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.   The resin that increases the dissolution rate in an alkaline developer by the action of an acid contains a repeating unit having a lactone structure, and the dissolution rate in an alkaline developer by the action of an acid according to any one of claims 1 to 4 Manufacturing method of resin.   A resin whose dissolution rate in an alkaline developer is increased by the action of the acid produced by the method according to claim 1. (A) a compound that generates an acid upon irradiation with an actinic ray or radiation, and
(B) a resin whose dissolution rate in an alkaline developer is increased by the action of the acid according to claim 6;
A positive photosensitive composition comprising:   A pattern forming method comprising: forming a film from the resist composition according to claim 7; and exposing and developing the film. A compound represented by formula (V).

In general formula (V),
Rv represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group or an alkoxy group.
n represents an integer of 1 to 3.