JP2010237334A - Active light sensitive or radiation sensitive resin composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active light sensitive or radiation sensitive resin composition which has high resolution, high sensitivity, and good line edge roughness and is hardly affected by variations of an exposure, and a pattern forming method using the same. <P>SOLUTION: The active light sensitive or radiation sensitive resin composition includes a resin (P) containing a recurring unit (a) having such a structure as to generate an acid anion in a side chain of the resin by irradiation of active light or radiation, a recurring unit (b) having a protected phenolic hydroxyl, and a recurring unit (x) having a group which is decomposed by action of an alkali developer to increase the dissolution rate in the alkali developer. The pattern forming method uses this resin composition. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photofabrication processes, and pattern formation using the same More particularly, the present invention relates to a positive resist composition for electron beam, X-ray or EUV light, a pattern forming method using the same, and a resin used for a radiation-sensitive composition.

Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Along with this, there is a tendency to shorten the exposure wavelength from g-line to i-line and further to KrF excimer laser light.
As a resist composition for KrF, those containing a resin mainly composed of polyhydroxystyrene have been developed. For example, a copolymer of hydroxystyrene and a monomer containing an adamantyl group has been known (Patent Document 1). ).
On the other hand, as a resist composition mainly using an ArF light source, a composition containing a resin not containing an aromatic ring has been developed. For example, a composition containing a resin having a specific lactone structure has been known (patents). Reference 2).

Furthermore, at present, in addition to excimer laser light, lithography using electron beams, X-rays, or EUV light is also being developed.
Lithography using an electron beam or EUV light is positioned as a next-generation or next-generation pattern forming technique, and a positive resist with high sensitivity is desired.
As a radiation sensitive composition for soft X-rays, for example, a composition containing a resin having a specific lactone structure and an acetal structure has been known (Patent Document 3).
In particular, high sensitivity is an important issue for shortening the wafer processing time. A chemically amplified positive resist generally contains a resin in which an alkali-soluble group is protected with an acid-decomposable group to make it insoluble in alkali and a photoacid generator. The photoacid generator is decomposed by exposure to generate an acid, the acid decomposes the acid-decomposable group while diffusing in the resist film, and the resin is alkali-solubilized.
On the other hand, process margins such as exposure latitude (EL) are also important requirements in terms of performance. It is known that EL deteriorates when acid diffuses.

In order to achieve high sensitivity, it is preferable to increase the amount of deprotection per number of generated acids, but at this time, acid diffusion is accompanied at the same time, so it is difficult to achieve both high sensitivity and high EL.
In order to achieve high sensitivity while suppressing acid diffusion, it is considered effective to increase acid generation efficiency. For that purpose, it is sufficient if the decomposition efficiency of the photoacid generator can be increased or the concentration thereof can be increased, but if the concentration of the photoacid generator is increased, the photoacid generator aggregates, deterioration of stability over time, precipitation There were harmful effects such as.

US Patent Application Publication No. 2007-0121390 JP 2008-031298 A JP 2003-345023 A

  An object of the present invention is to solve the problem of performance improvement technology in microfabrication of a semiconductor device using actinic rays or radiation, particularly electron beam, X-ray or EUV light, and has high resolution, high sensitivity, It is an object to provide an actinic ray-sensitive or radiation-sensitive resin composition that has good line edge roughness and is not easily affected by fluctuations in exposure amount, that is, high EL, and a pattern forming method using the same.

In the present invention, in order to realize high sensitivity while suppressing acid diffusion, a photoacid generator is supported on the resin to completely suppress acid diffusion. However, if acid diffusion is completely suppressed, the pattern shape is easily affected by fluctuations in the exposure dose. Therefore, by introducing a development auxiliary group, the effect of fluctuations in exposure is reduced, resulting in high resolution, high sensitivity, good line edge roughness, and low sensitivity to exposure fluctuations. A light-sensitive or radiation-sensitive resin composition was developed.
Specifically, it has the following configuration.

一般式（ＩＩＩ）〜（Ｖ）中、
Ａは、活性光線又は放射線の照射により分解して酸アニオンを生じる構造部位を表す。
Ｒ₀₄、Ｒ₀₅及びＲ₀₇〜Ｒ₀₉は、各々独立に、水素原子、アルキル基、シクロアルキル基、ハロゲン原子、シアノ基又はアルコキシカルボニル基を表す。
Ｒ₀₆は、シアノ基、カルボキシル基、−ＣＯ−ＯＲ₂₅又は−ＣＯ−Ｎ（Ｒ₂₆）（Ｒ₂₇）を表す。Ｒ₂₆とＲ₂₇が結合して窒素原子とともに環を形成してもよい。
Ｘ₁ 〜Ｘ₃ は、各々独立に、単結合、アリーレン基、アルキレン基、シクロアルキレン基、−Ｏ−、−ＳＯ₂ −、−ＣＯ−、−Ｎ（Ｒ₃₃）−又はこれらの複数を組み合わせた２価の連結基を表す。
Ｒ₂₅は、アルキル基、シクロアルキル基、アルケニル基、アリール基又はアラルキル基を表す。
Ｒ₂₆、Ｒ₂₇及びＲ₃₃は、各々独立に、水素原子、アルキル基、シクロアルキル基、アルケニル基、アリール基又はアラルキル基を表す。 1.
A repeating unit (a) having a structure in which an acid anion is generated by irradiation with an actinic ray or radiation on a side chain of the resin,
A repeating unit (b) having a protected phenolic hydroxyl group, and
A repeating unit (x) having a group that decomposes under the action of an alkali developer and increases the dissolution rate in the alkali developer,
Actinic ray-sensitive or radiation-sensitive resin composition comprising a resin (P) containing
2.
2. The actinic ray according to 1 above, wherein the resin (P) contains, as the repeating unit (a), at least one repeating unit selected from the following general formulas (III) to (V): Or radiation sensitive resin composition.

In general formulas (III) to (V),
A represents a structural site that decomposes upon irradiation with actinic rays or radiation to generate an acid anion.
R ₀₄ , R ₀₅ and R _{07 to} R ₀₉ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
R ₀₆ represents a cyano group, a carboxyl group, —CO—OR ₂₅ or —CO—N (R ₂₆ ) (R ₂₇ ). R ₂₆ and R ₂₇ may combine to form a ring with the nitrogen atom.
X _{1 to} X ₃ are each independently a single bond, an arylene group, an alkylene group, a cycloalkylene group, —O—, —SO ₂ —, —CO—, —N (R ₃₃ ) —, or a combination thereof. Represents a divalent linking group.
R ₂₅ represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.
R ₂₆ , R ₂₇ and R ₃₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.

一般式（Ｉ）中、
Ｒ₀₁、Ｒ₀₂及びＲ₀₃は、各々独立に、水素原子、アルキル基、シクロアルキル基、ハロゲン原子、シアノ基又はアルコキシカルボニル基を表す。Ｒ₀₃はＡｒ_１と結合して５員若しくは６員環を形成していても良い。
Ａｒ₁は、ｎ＋１価の芳香環基を表す。
ｎ個のＹは、各々独立に、水素原子又は酸の作用により脱離する基を表す。但し、Ｙの少なくとも１つは、酸の作用により脱離する基を表す。
ｎは、１〜４の整数を表す。 3.
3. The actinic ray-sensitive or radiation-sensitive resin composition as described in 2 above, wherein A in the general formulas (III) to (V) is a structural moiety containing a sulfonium salt structure or an iodonium salt structure.
4).
4. The actinic ray-sensitive or radiation-sensitive resin composition as described in any one of 1 to 3 above, wherein the repeating unit (b) is a repeating unit represented by the following general formula (I).

In general formula (I),
R ₀₁ , R ₀₂ and R ₀₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. R ₀₃ may be bonded to Ar ₁ to form a 5-membered or 6-membered ring.
Ar ₁ represents an n + 1 valent aromatic ring group.
n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of Y represents a group capable of leaving by the action of an acid.
n represents an integer of 1 to 4.

一般式（ＩＩ）中、
Ｌ₁及びＬ₂は、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基又はアラルキル基を表す。
Ｍは、単結合又は２価の連結基を表す。
Ｑは、アルキル基、シクロアルキル基、ヘテロ原子を含んでいてもよい脂環基、ヘテロ原子を含んでいてもよい芳香環基、アミノ基、アンモニウム基、メルカプト基、シアノ基又はアルデヒド基を表す。
Ｑ、Ｍ、Ｌ₁の少なくとも２つが結合して環を形成しても良い。 5).
5. The actinic ray-sensitive or radiation-sensitive resin composition as described in 4 above, wherein the group leaving by the action of an acid of Y in the general formula (I) is represented by the following general formula (II): object.

In general formula (II),
L ₁ and L ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alkyl group, a cycloalkyl group, an alicyclic group which may contain a hetero atom, an aromatic ring group which may contain a hetero atom, an amino group, an ammonium group, a mercapto group, a cyano group or an aldehyde group. .
At least two of Q, M, and L ₁ may combine to form a ring.

6).
The group in which the repeating unit (x) has a partial structure which is decomposed by the action of an alkali developer and increases the dissolution rate in the alkali developer has a lactone structure, a cyclic amide structure, or a cyclic acid anhydride structure. The actinic ray-sensitive or radiation-sensitive resin composition as described in any one of 1 to 5 above.
7).
7. The actinic ray-sensitive or radiation-sensitive resin composition as described in 6 above, wherein the group that decomposes under the action of an alkali developer and increases the dissolution rate in the alkali developer is a group having a lactone structure. .
8).
The actinic ray-sensitive or radiation-sensitive resin composition as described in any one of 1 to 7 above, which is for electron beam, X-ray or EUV light.
9.
A pattern forming method comprising: forming a resist film using the composition according to any one of 1 to 8 above, and exposing and developing the resist film.
10.
10. The pattern forming method as described in 9 above, wherein the exposure is performed using an electron beam, an X-ray or EUV light.

  According to the present invention, high resolution, high sensitivity, and good line edge roughness in an ultrafine region, particularly in electron beam, X-ray or EUV light lithography, and a feeling that is hardly affected by fluctuations in exposure amount. An actinic ray-sensitive or radiation-sensitive resin composition and a pattern forming method using the same can be provided.

Hereinafter, the present invention will be described in detail.
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).
In the present invention, “active light” or “radiation” means, for example, an emission line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays, X-rays, electron beams and the like. In the present invention, light means actinic rays or radiation.
In addition, “exposure” in the present specification is represented not only by exposure to deep ultraviolet rays, X-rays, EUV light and the like, but also by particle beams such as electron beams and ion beams, unless otherwise specified, such as mercury lamps and excimer lasers. Drawing is also included in the exposure.
The actinic ray-sensitive or radiation-sensitive resin composition in the present invention is preferably a positive chemically amplified resist composition.

  The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is suitably exposed to electron beam, X-ray or EUV light.

<Resin (P)>
The actinic ray-sensitive or radiation-sensitive resin composition is
A repeating unit (a) having a structure in which an acid anion is generated in the side chain of the resin by irradiation with actinic rays or radiation in the side chain;
A repeating unit (b) having a protected phenolic hydroxyl group, and
A repeating unit (x) having a group that decomposes under the action of an alkali developer and increases the dissolution rate in the alkali developer,
A resin (P) containing

・ Repeating unit (a)
As the repeating unit (a), any repeating unit capable of generating an acid anion by being decomposed by irradiation with actinic rays or radiation on the side chain can be used.

  As the repeating unit (a), for example, a repeating unit represented by any one of the following general formulas (III) to (V) is preferable.

In general formulas (III) to (V),
A represents a structural site that decomposes upon irradiation with actinic rays or radiation to generate an acid anion.
R ₀₄ , R ₀₅ and R _{07 to} R ₀₉ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
R ₀₆ represents a cyano group, a carboxyl group, —CO—OR ₂₅ or —CO—N (R ₂₆ ) (R ₂₇ ). R ₂₆ and R ₂₇ may combine to form a ring with the nitrogen atom.
X _{1 to} X ₃ are each independently a single bond, an arylene group, an alkylene group, a cycloalkylene group, —O—, —SO ₂ —, —CO—, —N (R ₃₃ ) —, or a combination thereof. Represents a divalent linking group.
R ₂₅ represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.
R ₂₆ , R ₂₇ and R ₃₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.

In R _{04 to} R ₀₅ , R _{07 to} R ₀₉ , R _{25 to} R ₂₇ , and R ₃₃ , the alkyl group may be linear or branched, preferably a methyl group that may have a substituent, Examples thereof include alkyl groups having 20 or less carbon atoms such as ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group and dodecyl group, and more preferably 8 carbon atoms. The following alkyl groups are mentioned.
The cycloalkyl group may be monocyclic or polycyclic, and may further have a substituent. Preferably, a monocyclic cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group is exemplified.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is more preferable.
As the alkyl group contained in the alkoxycarbonyl group, the same alkyl groups as those described above for R _{04 to} R ₀₅ and R _{07 to} R ₀₉ are preferable.

Preferred examples of the alkenyl group include those having 2 to 6 carbon atoms, such as a vinyl group, propenyl group, allyl group, butenyl group, pentenyl group, hexenyl group, and cyclohexenyl group which may have a substituent. It is done.
As the aryl group, a monocyclic or polycyclic aromatic group having 6 to 14 carbon atoms which may have a substituent is preferable. Specifically, a phenyl group, a tolyl group, a chlorophenyl group, a methoxyphenyl group, A naphthyl group etc. are mentioned. In addition, aryl groups may be bonded to form a multicycle.
Examples of the aralkyl group include those having 7 to 15 carbon atoms which may have a substituent such as a benzyl group, a phenethyl group, or a cumyl group.
The ring that can be formed by combining R ₂₆ and R ₂₇ together with the nitrogen atom is preferably a ring that forms a 5- to 8-membered ring. Specific examples include pyrrolidine, piperidine, and piperazine.

The arylene group of X _{1 to} X ₃ is preferably an arylene group having 6 to 14 carbon atoms which may have a substituent, and specific examples thereof include a phenylene group, a tolylene group and a naphthylene group.
The alkylene group is preferably an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group and an octylene group.
Preferred examples of the cycloalkylene group include those having 5 to 8 carbon atoms such as a cyclopentylene group and a cyclohexylene group which may have a substituent.

Preferred examples of the substituent that each of these groups may further have include a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, an amide group, a sulfonamide group, R _{04 to} R. ₀₉ , alkoxy groups such as alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups, hydroxypropoxy groups, butoxy groups, alkoxy groups such as methoxycarbonyl groups, ethoxycarbonyl groups, etc., mentioned in R _{25 to} R ₂₇ , R ₃₃ Examples thereof include acyl groups such as carbonyl group, formyl group, acetyl group and benzoyl group, acyloxy groups such as acetoxy group and butyryloxy group, and carboxy groups, and the number of carbon atoms of the substituent which may further be present is preferably 8 or less.

A represents a structural site that decomposes upon irradiation with actinic rays or radiation to generate an acid anion, specifically, photoinitiator for photocationic polymerization, photoinitiator for photoradical polymerization, photodecolorant for dyes, Examples thereof include a structural portion possessed by a compound that generates an acid anion by known light used in a photochromic agent or a microresist.
Examples of the structural site that generates an acid anion upon irradiation with actinic rays or radiation include onium structural sites such as diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, and arsonium salts.

  A is more preferably an ionic structural site containing a sulfonium salt or an iodonium salt. More specifically, A is preferably a group represented by the following general formula (ZI) or (ZII).

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
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).
Z ⁻ represents an acid anion generated by decomposition upon irradiation with actinic rays or radiation, and is preferably a non-nucleophilic anion. Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.
A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. As a result, the temporal stability of the resin is improved, and the temporal stability of the resist is also improved.

_Examples of the organic group for R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include an aryl group, an alkyl group, and a cycloalkyl group.
Of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ , at least one is preferably an aryl group, more preferably all three are aryl groups. As the aryl group, in addition to a phenyl group, a naphthyl group, and the like, a heteroaryl group such as an indole residue and a pyrrole residue can be used. These aryl groups may further have a substituent. Examples of the substituent include halogen atoms such as nitro groups and fluorine atoms, carboxyl groups, hydroxyl groups, amino groups, cyano groups, alkoxy groups (preferably having 1 to 15 carbon atoms), cycloalkyl groups (preferably having 3 to 15 carbon atoms). ), An aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 2 carbon atoms). 7) and the like, but are not limited thereto.

Preferred structures when at least one of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is not an aryl group include paragraphs 0047 and 0048 of JP-A-2004-233661, paragraphs 0040 to 0046 of JP-A-2003-35948, Compounds exemplified as formulas (I-1) to (I-70) in U.S. Patent Application Publication No. 2003/0224288, and Formulas (IA-1) to (U.S. Patent Application Publication No. 2003/0077540) Examples thereof include cation structures such as (IA-54) and compounds exemplified as formulas (IB-1) to (IB-24).

In the general formula (ZII), R ₂₀₄ ~R ₂₀₅ each independently represents an aryl group, an alkyl group or a cycloalkyl group. These aryl group, alkyl group, and cycloalkyl group are the same as the aryl group described as the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the aforementioned compound (ZI).
Aryl group, alkyl group of R ₂₀₄ to R _205, cycloalkyl groups may have a substituent. Examples of the substituent include those that the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the above-described compound (ZI) may have.

Z ⁻ represents an acid anion generated by decomposition upon irradiation with actinic rays or radiation, and is preferably a non-nucleophilic anion, and examples thereof include the same as Z ⁻ in the general formula (ZI).

Moreover, as a structural site | part which generate | occur | produces an acid anion by irradiation of actinic light or a radiation, the structural site | part used as the sulfonic acid precursor which the following photoacid generator has can also be mentioned, for example.
M.M. TUNOOKA et al, Polymer Preprints Japan, 35 (8), G.M. Berner et al. Rad. Curing, 13 (4), W.M. J. et al. Mijs et al, Coating Technol. , 55 (697), 45 (1983), Akzo, H .; Adachietal, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84515, 199,672, 044,115, 0101,122, US Pat. No. 618,564, Represented by the iminosulfonates described in JP-A-4,371,605, JP-A-4,431,774, JP-A-64-18143, JP-A-2-245756, and Japanese Patent Application 3-140109. Compounds that generate sulfonic acid by photolysis, disulfone compounds described in JP-A No. 61-166544, and the like; N. R. Pillai, Synthesis, (1), 1 (1980), A.M. Abad et al., Tetrahedron Lett. , (47) 4555 (1971), D.M. H. R. Barton et al. Chem. Soc. , (C), 329 (1970), US Pat. No. 3,779,778, European Patent 126,712, etc.

  The repeating unit (b) is more preferably a structure that generates an acid anion in the side chain of the resin upon irradiation with actinic rays or radiation. When such a structure is selected, diffusion of the generated acid anion is suppressed, which is effective from the viewpoint of improving the resolution and improving the line edge roughness.

  Although the preferable specific example of the partial structure represented by A is given below, it is not specifically limited to these.

  As the repeating unit represented by any one of the general formulas (III) to (V) effectively used in the present invention, more preferably, the following general formulas (III-1) to (III-6), What is represented by either (IV-1)-(IV-4) and general formula (V-1)-(V-2) can be mentioned.

In the general formula, Ar _1a represents an arylene group which may have a substituent, similar to the arylene groups represented by X _{1 to} X ₃ .
Ar _{2 a to} Ar _{4 a} may have a substituent similar to the aryl groups represented by R _{201 to} R ₂₀₃ and R _{204 to} R ₂₀₅ in the general formulas (ZI) and (ZII). Represents an aryl group.
R ₀₁ represents a hydrogen atom, a methyl group, a chloromethyl group, a trifluoromethyl group, or a cyano group.
R ₀₂ and R ₀₂₁ are the same as those represented by X _{1 to} X ₃ , such as a single bond, an arylene group, an alkylene group, a cycloalkylene group, —O—, —SO ₂ —, CO—, —N (R ₃₃ )-Or a divalent linking group in which a plurality of these are combined.

R ₀₃ and R ₀₁₉ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Examples of the alkyl group and cycloalkyl group include the same alkyl groups and cycloalkyl groups as R _{01 to} R ₀₃ in the general formula (I) described later. As an aryl group and an aralkyl group, the same thing as the aryl group and aralkyl group as L < ₁ > -L < ₂ > in postscript general formula (II) can be mentioned.

  Preferred examples of the repeating structural unit represented by the repeating unit represented by any one of the general formula (III) to general formula (V) include those represented by the following general formula.

In the general formula, Ar ₁ represents an arylene group which may have a substituent, similar to the arylene group represented by X _{1 to} X ₃ above. Ar ₆ and Ar ₇ represent an aryl group which may have a substituent, similar to the aryl group represented by R _{25 to} R ₂₇ described above. R ₀₁ represents a hydrogen atom, a methyl group, a chloromethyl group or a cyano group.

R ₀₂ represents the same arylene group, alkylene group or cycloalkylene group as that represented by X _{1 to} X ₃ .
R ₀₃ , R _{05 to} R ₀₁₀ , R ₀₁₃ , R _{015 to} R ₀₁₉ , and R ₀₂₂ represent the same alkyl group, haloalkyl group, cycloalkyl group, aryl group, and aralkyl group as those described above.
R ₀₄ represents an arylene group which may have a substituent, an alkylene group, and further an alkenylene group having 2 to 6 carbon atoms which may have a substituent, as described above. As the alkenyl group, an alkenylene group having 2 to 6 carbon atoms such as an ethylene group, a propenylene group, and a butenylene group which may have a substituent is preferable.

R ₀₁₁ and R ₀₁₄ represent a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), and an alkyl group, an alkoxy group, an alkoxycarbonyl group, and an acyloxy group shown as preferred further substituents as described above.
R ₀₁₂ represents a nitro group, a cyano group, or a perfluoroalkyl group such as a trifluoromethyl group or a pentafluoroethyl group.
X ⁻ represents an anion of aryl sulfonic acid, heteroaryl sulfonic acid, alkyl sulfonic acid, cycloalkyl sulfonic acid, or perfluoroalkyl sulfonic acid.

  Specific examples of the repeating unit represented by any one of the general formulas (III) to (V) are shown below, but the present invention is not limited thereto.

  In addition, as specific examples of the repeating unit represented by any one of the general formula (III) to the general formula (V), the resin side chain in the examples (a1) to (a196) in JP-A-10-221852 In addition, those having a structure generating an acid anion are also included.

The content of the repeating unit (a) in the resin of the present invention is preferably 0.5 to 80 mol%, preferably 1 to 60 mol%, based on all repeating units. Is more preferable, and it is especially preferable to contain in 3-40 mol%.
The method for synthesizing the monomer corresponding to the repeating unit (a) is not particularly limited. For example, the monomer is synthesized by exchanging an acid anion having a polymerizable unsaturated bond corresponding to the repeating unit and a known onium salt halide. A method is mentioned.
More specifically, a metal ion salt (for example, sodium ion, potassium ion, etc.) or an ammonium salt (ammonium, triethylammonium salt, etc.) of an acid having a polymerizable unsaturated bond corresponding to the repeating unit, and a halogen ion ( An onium salt having a chloride ion, bromide ion, iodide ion, etc.) is stirred in the presence of water or methanol to carry out an anion exchange reaction, such as dichloromethane, chloroform, ethyl acetate, methyl isobutyl ketone, tetrahydroxyfuran, etc. By performing a liquid separation / washing operation with an organic solvent and water, a monomer corresponding to the target repeating unit (a) can be synthesized.
After anion exchange reaction by stirring in the presence of an organic solvent that can be separated from water, such as dichloromethane, chloroform, ethyl acetate, methyl isobutyl ketone, and tetrahydroxyfuran, and water separation, washing with water It can also be synthesized by operating.

・ Repeating unit (b)
The repeating unit (b) having a protected phenolic hydroxyl group has at least one phenolic hydroxyl group and is protected by a group in which part or all of the hydrogen atoms of the hydroxyl group are eliminated by the action of an acid. It is a repeating unit.
Examples of the structure that is decomposed by the action of an acid and increases the solubility in an aqueous alkali solution include groups represented by -COOA ⁰ and -O-B ⁰ groups. Further Examples of the group containing these, include groups represented by -R ⁰ -COOA ^0, or -Ar-O-B ^0. Here, A ⁰ is -C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -Si (R ⁰¹ ) (R ⁰² ) (R ⁰³ ) or -C (R ⁰⁴ ) (R ⁰⁵ ) -O-R ⁰⁶ groups are shown. B ⁰ represents an A ⁰ or —CO—O—A ⁰ group. R ⁰¹ , R ⁰² , R ⁰³ , R ⁰⁴ and R ⁰⁵ are the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, and R ⁰⁶ represents an alkyl group or an aryl group. However, at least two of R ^{01 to} R ⁰³ are groups other than hydrogen atoms, and two groups of R ^{01 to} R ⁰³ and R ^{04 to} R ⁰⁶ may be bonded to form a ring. Good. R ⁰ represents a divalent aliphatic or aromatic hydrocarbon group which may have a substituent, and —Ar— represents a divalent aromatic which may have a monocyclic or polycyclic substituent. Indicates a group.

  As the repeating unit (b), for example, a repeating structural unit represented by the following general formula (I) is preferable.

Here, R ₀₁ , R ₀₂ and R ₀₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. R ₀₃ represents an alkylene group and may be bonded to Ar ₁ to form a 5-membered or 6-membered ring.
Ar ₁ represents an aromatic ring group.
n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of Y represents a group capable of leaving by the action of an acid.
n represents an integer of 1 to 4.

The alkyl group represented by R _{01 to} R ₀₃ in the general formula is preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, hexyl group, which may have a substituent, An alkyl group having 20 or less carbon atoms such as 2-ethylhexyl group, octyl group or dodecyl group is exemplified, and an alkyl group having 8 or less carbon atoms is more preferable.
The alkyl group contained in the alkoxycarbonyl group is preferably the same as the alkyl group in R _{01 to} R ₀₃ .
Examples of the cycloalkyl group include cycloalkyl groups that may be monocyclic or polycyclic. Preferable examples include a monocyclic cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group which may have a substituent.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is more preferable.
When R ₀₃ represents an alkylene group, the alkylene group is preferably an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octylene group.

The aromatic ring group of Ar ₁ preferably has 6 to 14 carbon atoms which may have a substituent, and specific examples thereof include a benzene ring, a toluene ring, a naphthalene ring and the like.

n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of n represents a group capable of leaving by the action of an acid.
Examples of the group Y leaving by the action of an acid include —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (═O) —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ). ), -C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ) -C (= O) -O-C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —CH (R ₃₆ ) (Ar) and the like can be mentioned.

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.
Ar represents an aryl group.
The alkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl. Group, octyl group and the like.
The cycloalkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclododecyl group. Group, androstanyl group and the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
The aryl group of R _{36 to} R ₃₉ , R ₀₁ , R ₀₂ and Ar is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.
The aralkyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.
The alkenyl group of R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.

The ring formed by combining R ₃₆ and R ₃₇ with each other may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkane structure having 3 to 8 carbon atoms, and examples thereof include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure. As the polycyclic type, a cycloalkane structure having 6 to 20 carbon atoms is preferable, and examples thereof include an adamantane structure, a norbornane structure, a dicyclopentane structure, a tricyclodecane structure, and a tetracyclododecane structure. A part of carbon atoms in the cycloalkane structure may be substituted with a hetero atom such as an oxygen atom.
Each of the above groups as R _{36 to} R ₃₉ , R ₀₁ , R ₀₂ , R _03, Ar and Ar ₁ may further have a substituent. , Alkyl group, cycloalkyl group, aryl group, amino group, amide group, ureido group, urethane group, hydroxyl group, carboxyl group, halogen atom, alkoxy group, thioether group, acyl group, acyloxy group, alkoxycarbonyl group, cyano group , A nitro group and the like, and the number of carbon atoms of the substituent which may be further included is preferably 8 or less.

  The group Y that is eliminated by the action of an acid is more preferably a structure represented by the following general formula (II).

Here, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alkyl group, a cycloalkyl group, an alicyclic group which may contain a hetero atom, an aromatic ring group which may contain a hetero atom, an amino group, an ammonium group, a mercapto group, a cyano group or an aldehyde group. .
At least two of Q, M, and L ₁ may combine to form a ring.

The alkyl group as L ₁ and L ₂ is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group. An octyl group can be preferably mentioned.
The cycloalkyl group as L ₁ and L ₂ is, for example, a cycloalkyl group having 3 to 15 carbon atoms, and specifically, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group can be preferably exemplified.
The aryl group as L ₁ and L ₂ is, for example, an aryl group having 6 to 15 carbon atoms, and specific examples thereof include a phenyl group, a tolyl group, a naphthyl group, and an anthryl group.
The aralkyl group as L ₁ and L ₂ has, for example, 6 to 20 carbon atoms, and examples thereof include a benzyl group and a phenethyl group.

The divalent linking group as M is, for example, an alkylene group (for example, methylene group, ethylene group, propylene group, butylene group, hexylene group, octylene group, etc.), cycloalkylene group (for example, cyclopentylene group, cyclohexylene group). Group), alkenylene group (for example, ethylene group, propenylene group, butenylene group, etc.), arylene group (for example, phenylene group, tolylene group, naphthylene group, etc.), -S-, -O-, -CO-, -SO _2- , -N (R ₀ )-, and a divalent linking group in which a plurality of these are combined. R ₀ represents a hydrogen atom or an alkyl group (for example, an alkyl group having 1 to 8 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group). Octyl group, etc.).
The alkyl group and cycloalkyl group as Q are the same as the above groups as L ₁ and L ₂ .
As the alicyclic group and the aromatic ring group in the alicyclic group which may contain a hetero atom as Q and the aromatic ring group which may contain a hetero atom, the cycloalkyl as L ₁ and L ₂ described above is used. Group, an aryl group, etc. are mentioned, Preferably it is C3-C15.
Examples of the alicyclic group containing a hetero atom and the aromatic ring group containing a hetero atom include thiirane, cyclothiolane, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole. And groups having a heterocyclic structure such as pyrrolidone, but are not limited to these as long as the structure is generally called a heterocyclic ring (a ring formed of carbon and a heteroatom, or a ring formed of a heteroatom). .

Q, M, as a ring which may be formed by combining at least two L _1, Q, M, by combining at least two L _1, for example, a propylene group, to form a butylene group, an oxygen atom In the case of forming a ring containing, a 5-membered or 6-membered ring is preferable.
Each group represented by L ₁ , L ₂ , M, and Q in the general formula (II) may have a substituent. For example, R _{36 to} R ₃₉ , R ₀₁ , R ₀₂ , _{Examples of the} substituent that may be possessed by R _03, Ar and Ar ₁ are mentioned, and the substituent preferably has 8 or less carbon atoms.

  The group represented by -MQ is preferably a group composed of 1 to 30 carbon atoms, more preferably a group composed of 5 to 20 carbon atoms.

  Specific examples of the repeating unit represented by the general formula (I) are shown below, but are not limited thereto.

The content of the repeating unit (b) in the resin of the present invention is preferably 3 to 90 mol%, more preferably 5 to 80 mol%, based on all repeating units. Preferably, it is contained in the range of 7 to 70 mol%.
The ratio of the repeating unit (a) to the repeating unit (b) in the resin (number of moles of A / number of moles of B) is preferably 0.04 to 1.0, more preferably 0.05 to 0.9. 0.06-0.8 is particularly preferable.

A repeating unit (x) having a group that decomposes by the action of an alkali developer and increases the dissolution rate in the alkali developer
The resin (P) of the present invention has a repeating unit (x) having a group (also referred to as a development auxiliary group) that is decomposed by the action of an alkali developer and increases the dissolution rate in the alkali developer. As a result, the development assisting group is decomposed during alkali development, and the dissolution rate in the alkali developer is increased.
The development auxiliary group is, for example, a group that decomposes with an alkaline developer to generate a hydrophilic functional group. Examples of the hydrophilic functional group include alkali-soluble groups such as a carboxyl group and a hydroxyl group.
The development auxiliary group includes, for example, a group having a lactone structure, a carboxylic acid ester group substituted with a polar group such as a halogen atom, a group having an acid anhydride structure, a group having a cyclic amide structure, an acid amide group, a carboxylic acid thioester , Carbonic acid ester, sulfuric acid ester, sulfonic acid ester and the like, preferably a group having at least one partial structure of a lactone structure, a cyclic amide structure and a cyclic acid anhydride structure, more preferably a lactone group.
Carboxylic acid ester groups not substituted with polar groups such as halogen atoms (for example, ester groups directly connected to the main chain of the (meth) acrylate repeating unit and not substituted with polar groups such as halogen atoms) Since the speed of the decomposition reaction with the alkali developer is slow, it is not included in the “group that decomposes by the action of the alkali developer and increases the solubility in the alkali developer” in the present application.

  As the group having a lactone structure, any group having a lactone structure can be used, but a 5- to 7-membered ring lactone structure is preferable, and a bicyclo structure or a spiro structure is added to the 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed in the form to be formed are preferred. It is more preferable to have a repeating unit having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-17). The 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), and (LC1-17). By using this lactone structure, line edge roughness and 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. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferably, they are a C1-C4 alkyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

  Examples of the repeating unit having a lactone structure represented by any one of the general formulas (LC1-1) to (LC1-17) 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. Preferred substituents that the alkyl group represented by Rb ₀ may have include a hydroxyl group and a halogen atom. Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferred are a hydrogen atom, a methyl group, a hydroxymethyl group, and a trifluoromethyl group, and a hydrogen atom and a methyl group are particularly preferred.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by.
Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.
V represents a group having a structure represented by any one of the general formulas (LC1-1) to (LC1-17).

  The repeating unit having a lactone group 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.

  Specific examples of the repeating unit (x) are shown below, but the present invention is not limited thereto.

Particularly preferred repeating units having a lactone group include the following repeating units. By selecting an optimal lactone group, the pattern profile and the density dependency are improved. In the formula, Rx and R represent H, CH ₃ , CH ₂ OH, or CF ₃ .

The repeating unit (x) having a group that decomposes by the action of an alkali developer and increases the dissolution rate in the alkali developer includes an alkali in the main chain of the resin, such as a repeating unit of an acrylate ester or a methacrylate ester. Polymerization initiators and chain transfer agents having repeating units to which groups that decompose by the action of the developer and increase the dissolution rate in the alkali developer are bonded, or groups that increase the dissolution rate in the alkali developer Is preferably used at the time of polymerization and introduced at the end of the polymer chain.
The content of the repeating unit (x) having a group capable of increasing the dissolution rate in an alkali developer is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, still more preferably based on all repeating units in the polymer. Is 5 to 15 mol%.

(3) Repeating unit (C)
The resin in the present invention preferably further has a repeating unit (C) represented by the following general formula (VI).

Here, R ₀₁ , R ₀₂ and R ₀₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. R ₀₃ represents an alkylene group and may be bonded to Ar ₁ to form a 5-membered or 6-membered ring.
Ar ₁ represents an aromatic ring group.
n represents an integer of 1 to 4.

In the general formula _{(VI), R 01, R} 02, R 03, and specific examples of Ar ₁ are in the general formula _{(I), R 01, R} 02, R 03, and similarly to the Ar ₁ belongs to.

  Specific examples of the repeating unit represented by the general formula (VI) are shown below, but are not limited thereto.

  The content of the repeating unit (C) in the resin of the present invention is preferably 3 to 90 mol%, more preferably 5 to 80 mol%, based on all repeating units. Preferably, it is contained in the range of 7 to 70 mol%.

(4) Form of Resin (P) of the Present Invention, Polymerization Method, Molecular Weight, etc. The form of the resin (P) may be any of random type, block type, comb type, and star type.
The resin (P) according to the present invention containing the above repeating units (a), (b) and (x) is synthesized, for example, by radical, cation or anion polymerization of unsaturated monomers corresponding to each structure. Can do. It is also possible to obtain the desired resin by conducting a polymer reaction after polymerization using an unsaturated monomer corresponding to the precursor of each structure.

  The resin according to the present invention preferably has 0.5 to 80 mol% of the repeating unit (a), 3 to 90 mol% of the repeating unit (b), and 3 to 90 mol% of the repeating unit (C).

The molecular weight of the resin (P) according to the present invention is not particularly limited, but the weight average molecular weight is preferably in the range of 1000 to 100,000, more preferably in the range of 1500 to 70000, and in the range of 2000 to 50000. It is particularly preferred. Here, the weight average molecular weight of the resin indicates a molecular weight in terms of polystyrene measured by GPC (carrier: THF or N-methyl-2-pyrrolidone (NMP)).
The dispersity (Mw / Mn) is preferably 1.00 to 5.00, more preferably 1.03 to 3.50, and still more preferably 1.05 to 2.50.

Further, for the purpose of improving the performance of the resin according to the present invention, it may further have repeating units derived from other polymerizable monomers as long as the dry etching resistance is not significantly impaired.
The content of repeating units derived from other polymerizable monomers in the resin is generally 50 mol% or less, preferably 30 mol% or less, based on all repeating units. Other polymerizable monomers that can be used include those shown below. For example, it is a compound having one addition polymerizable unsaturated bond selected from (meth) acrylic acid esters, (meth) acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic acid esters and the like. . In addition, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilonitrile, and the like can be given. In general, any addition-polymerizable unsaturated compound copolymerizable with the repeating unit according to the present invention can be used without any particular limitation.

Resin (P) of this invention can be used individually by 1 type or in combination of 2 or more types.
The content of the resin (P) is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, based on the total solid content in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention. ˜100 mass% is particularly preferred.

  The polymerization reaction of the resin (P) 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 examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The concentration of the reaction is 5 to 50% by mass, preferably 30 to 50% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

  After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer, and may be a hydrocarbon, halogenated hydrocarbon, nitro, depending on the type of polymer. A compound, ether, ketone, ester, carbonate, alcohol, carboxylic acid, water, a mixed solvent containing these solvents, and the like can be appropriately selected for use. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

  The resin may be once deposited and separated, and then dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent. That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).

<Other ingredients>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention may further include a basic compound, a resin that decomposes by the action of an acid to increase the dissolution rate in alkaline water solubility, and a conventional photoacid as necessary. Generating agents, organic solvents, surfactants, acid-decomposable dissolution inhibiting compounds, dyes, plasticizers, photosensitizers, dissolution-promoting compounds for developers, and compounds having proton acceptor functional groups Can do.

<Basic compound>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention preferably contains a basic compound.
The basic compound is preferably a nitrogen-containing organic basic compound.
Although the compound which can be used is not specifically limited, For example, the compound classified into the following (1)-(4) is used preferably.

(1) Compound represented by the following general formula (BS-1)

In general formula (BS-1),
Each R independently represents a hydrogen atom, an alkyl group (straight or branched), a cycloalkyl group (monocyclic or polycyclic), an aryl group, or an aralkyl group. However, not all three Rs are hydrogen atoms.
Although carbon number of the alkyl group as R is not specifically limited, Usually, 1-20, Preferably it is 1-12.
Although carbon number of the cycloalkyl group as R is not specifically limited, Usually, 3-20, Preferably it is 5-15.
Although carbon number of the aryl group as R is not specifically limited, Usually, 6-20, Preferably it is 6-10. Specific examples include a phenyl group and a naphthyl group.
Although carbon number of the aralkyl group as R is not specifically limited, Usually, 7-20, Preferably it is 7-11. Specific examples include a benzyl group.
In the alkyl group, cycloalkyl group, aryl group or aralkyl group as R, a hydrogen atom may be substituted with a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, an alkylcarbonyloxy group, and an alkyloxycarbonyl group.
In the compound represented by the general formula (BS-1), it is preferable that only one of three Rs is a hydrogen atom, or all Rs are not hydrogen atoms.

Specific examples of the compound of the general formula (BS-1) include tri-n-butylamine, tri-n-pentylamine, tri-n-octylamine, tri-n-decylamine, triisodecylamine, dicyclohexylmethylamine, Tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, didecylamine, methyloctadecylamine, dimethylundecylamine, N, N-dimethyldodecylamine, methyldioctadecylamine, N, N-dibutylaniline, N, N- Examples include dihexylaniline, 2,6-diisopropylaniline, 2,4,6-tri (t-butyl) aniline.
In addition, a compound in which at least one R in the general formula (BS-1) is an alkyl group substituted with a hydroxyl group can be mentioned as one of preferable embodiments. Specific examples of the compound include triethanolamine and N, N-dihydroxyethylaniline.

The alkyl group as R may have an oxygen atom in the alkyl chain, and an oxyalkylene chain may be formed. The oxyalkylene chain is preferably —CH ₂ CH ₂ O—. Specific examples include tris (methoxyethoxyethyl) amine and compounds exemplified in column 3, line 60 of US Pat. No. 6,040,112.

(2) Compound having a nitrogen-containing heterocyclic structure The heterocyclic structure may or may not have aromaticity. Moreover, you may have two or more nitrogen atoms, Furthermore, you may contain hetero atoms other than nitrogen. Specifically, compounds having an imidazole structure (2-phenylbenzimidazole, 2,4,5-triphenylimidazole, etc.), compounds having a piperidine structure (N-hydroxyethylpiperidine, bis (1,2,2,6) , 6-pentamethyl-4-piperidyl) sebacate), compounds having a pyridine structure (such as 4-dimethylaminopyridine), and compounds having an antipyrine structure (such as antipyrine and hydroxyantipyrine).
A compound having two or more ring structures is also preferably used. Specific examples include 1,5-diazabicyclo [4.3.0] non-5-ene and 1,8-diazabicyclo [5.4.0] -undec-7-ene.

(3) Amine compound having a phenoxy group An amine compound having a phenoxy group has a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound. Examples of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. It may have a substituent.
More preferably, it is a compound having at least one oxyalkylene chain between the phenoxy group and the nitrogen atom. The number of oxyalkylene chains in one molecule is preferably 3-9, more preferably 4-6. Among the oxyalkylene chains, —CH ₂ CH ₂ O— is preferable.
Specific examples include 2- [2- {2- (2,2-dimethoxy-phenoxyethoxy) ethyl} -bis- (2-methoxyethyl)]-amine and US Patent Application Publication No. 2007/0224539. The compounds (C1-1) to (C3-3) exemplified in paragraph [0066] of the above.

(4) Ammonium salt Ammonium salts are also used as appropriate. Preferred is hydroxide or carboxylate. More specifically, tetraalkylammonium hydroxide represented by tetrabutylammonium hydroxide is preferable.

  In addition, compounds synthesized in Examples of JP-A No. 2002-363146, compounds described in paragraph 0108 of JP-A No. 2007-298869, and the like can also be used.

A basic compound is used individually or in combination of 2 or more types.
The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of the total solid of actinic-ray-sensitive or radiation-sensitive resin composition, Preferably it is 0.01-5 mass%.

The acid generator / basic compound molar ratio is preferably 1.5 to 300. That is, the molar ratio is preferably 2.5 or more from the viewpoints of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to pattern thickening over time until post-exposure heat treatment. The molar ratio is more preferably 2.0 to 200, and still more preferably 2.5 to 150.
The acid generator in the above molar ratio is the total amount of the repeating unit (a) contained in the resin (P) and the acid generator other than the resin (P) described later.

<Acid-decomposable resin>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention may contain, in addition to the resin (P), a resin that decomposes by the action of an acid to increase the dissolution rate with respect to alkali water solubility.

  Resins that decompose due to the action of an acid and increase the dissolution rate in an alkaline aqueous solution (hereinafter also referred to as “acid-decomposable resins”) are not included in the main chain or side chain of the resin, or both of the main chain and side chain. It is a resin having a group (acid-decomposable group) that decomposes by the action of and produces an alkali-soluble group. Among these, a resin having an acid-decomposable group in the side chain is more preferable.

The acid-decomposable resin is a precursor of a group that can be decomposed with an acid into an alkali-soluble resin as disclosed in European Patent No. 254853, JP-A-2-25850, JP-A-3-223860, JP-A-4-251259, and the like. It can be obtained by copolymerizing an alkali-soluble resin monomer having a group that can be reacted with the body or decomposable with an acid with various monomers.
As the acid-decomposable group, for example, in a resin having an alkali-soluble group such as —COOH group and —OH group, a group in which the hydrogen atom of the alkali-soluble group shown on the left is substituted with a group capable of leaving by the action of an acid is preferable.
Specifically, the acid-decomposable group is preferably the same group as the acid-decomposable group described in the above-described resin of the present invention (for example, the acid-decomposable group described as the repeating unit (b) in the resin (P)). As an example.

  The resin having an alkali-soluble group is not particularly limited. For example, poly (o-hydroxystyrene), poly (m-hydroxystyrene), poly (p-hydroxystyrene) and copolymers thereof, hydrogenated poly (Hydroxystyrene), poly (hydroxystyrene) s having a substituent represented by the following structure, and resins having a phenolic hydroxyl group, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, hydrogen An alkali-soluble resin having a hydroxystyrene structural unit such as a modified novolak resin, and an alkali-soluble resin containing a repeating unit having a carboxyl group such as (meth) acrylic acid or norbornenecarboxylic acid.

  The alkali dissolution rate of these alkali-soluble resins is preferably at least 170 kg / second as measured with 2.38 mass% tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 330 Å / second or more.

  The alkali-soluble resin monomer is not particularly limited. For example, alkylcarbonyloxystyrene (for example, t-butoxycarbonyloxystyrene), alkoxystyrene (for example, 1-alkoxyethoxystyrene, t-butoxystyrene), (meta ) Acrylic acid tertiary alkyl ester (for example, t-butyl (meth) acrylate, 2-alkyl-2-adamantyl (meth) acrylate, dialkyl (1-adamantyl) methyl (meth) acrylate, etc.)) and the like.

  The content of the group capable of decomposing with an acid is the number of repeating units (b) having a group decomposable with an acid in the resin and the number of repeating units having an alkali-soluble group that is not protected by a group capable of leaving with an acid. With (S), it is represented by B / (B + S). The content is preferably 0.01 to 0.7, more preferably 0.05 to 0.50, and still more preferably 0.05 to 0.40.

  The acid-decomposable resin is not particularly limited, but preferably has a repeating unit having an aromatic group, and is an acid-decomposable resin having hydroxystyrene as a repeating unit (for example, poly (hydroxystyrene / acid-decomposable group). (Hydroxystyrene) and poly (hydroxystyrene / (meth) acrylic acid protected with an acid-decomposable group)) are more preferred.

  As the acid-decomposable resin, a resin having a repeating unit represented by the following general formula (VI) and a repeating unit represented by the general formula (I) is particularly preferable.

  General formula (VI) and general formula (I) are the same as those in the resin (P).

The acid-decomposable resin may have a repeating unit derived from another polymerizable monomer.
The content of repeating units derived from other polymerizable monomers in the resin is generally 50 mol% or less, preferably 30 mol% or less, based on all repeating units. Examples of the repeating unit derived from another copolymerizable monomer that can be used include the same repeating unit as the repeating unit derived from another polymerizable monomer in the resin (P).

  The content of the repeating unit having an alkali-soluble group such as a hydroxyl group, a carboxy group, or a sulfonic acid group is preferably 1 to 99 mol%, more preferably 3 to 95 mol% in all repeating units constituting the acid-decomposable resin. Especially preferably, it is 5-90 mol%.

  The content of the repeating unit having an acid-decomposable group is preferably from 3 to 95 mol%, more preferably from 5 to 90 mol%, particularly preferably from 10 to 85 mol% in all repeating units constituting the acid-decomposable resin. It is.

The weight average molecular weight of the acid-decomposable resin is preferably 50,000 or less, more preferably 1,000 to 20,000, and particularly preferably 1,000 to 10,000 as a polystyrene conversion value by the GPC method.
The dispersity (Mw / Mn) of the acid-decomposable resin is preferably 1.0 to 3.0, more preferably 1.05 to 2.0, and still more preferably 1.1 to 1.7.

  Two or more acid-decomposable resins may be used in combination.

  Although the preferable specific example of an acid-decomposable resin is shown below, it is not limited to these.

  In the actinic ray-sensitive or radiation-sensitive resin composition of the present invention, the compounding amount in the composition of the acid-decomposable resin excluding the resin (P) is preferably 0 to 70% by mass in the total solid content of the composition, More preferably, it is 0-50 mass%, More preferably, it is 0-30 mass%.

<Acid generator>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention contains a resin (P) having a photoacid-generating structure. In addition to the resin (P), an acid is irradiated by irradiation with actinic rays or radiation. It may contain a low molecular compound that is generated (hereinafter also referred to as “acid generator”).
Examples of such an acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray or radiation used for a microresist. A known compound that generates an acid by irradiation and a mixture thereof can be appropriately selected and used.

Examples of the acid generator include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.
Specific examples thereof include those described in [0164] to [0248] of US Patent Application Publication No. 2008/0241737. Of these acid generators, sulfonium salts or iodonium salts are preferred. The acid anion possessed by the sulfonium salt or iodonium salt is preferably an alkylsulfonic acid anion, an arylsulfonic acid anion, a bis (alkylsulfonyl) imide anion, a tris (alkylsulfonyl) methide anion, or the like. The alkyl group and aryl group in these anions may be substituted.

In the actinic ray-sensitive or radiation-sensitive resin composition of the present invention, when an acid generator is used in addition to the resin (P) having a photoacid generating structure, the acid generator is used alone or in combination of two. The above can be used in combination. 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.
When an acid generator other than the resin (P) is used, the content of the acid generator is preferably 0 to 20% by mass based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition. Preferably it is 0.1-2 mass%.

<Solvent>
The solvent that can be used in preparing the actinic ray-sensitive or radiation-sensitive resin composition is not particularly limited as long as it dissolves each component. For example, an alkylene glycol monoalkyl ether carboxylate (propylene) Glycol monomethyl ether acetate (PGMEA; 1-methoxy-2-acetoxypropane etc.), alkylene glycol monoalkyl ether (propylene glycol monomethyl ether (PGME; 1-methoxy-2-propanol) etc.), lactate alkyl ester (ethyl lactate, Methyl lactate, etc.), cyclic lactone (γ-butyrolactone, etc., preferably 4-10 carbon atoms), chain or cyclic ketone (2-heptanone, cyclohexanone, etc., preferably 4-10 carbon atoms), alkylene carbonate (Ethylene carbonate, propylene carbonate), carboxylic acid alkyl (alkyl acetate such as butyl acetate is preferred), and the like alkoxy alkyl acetates (ethyl ethoxypropionate). Other usable solvents include, for example, the solvents described in US Patent Application Publication No. 2008/0248425 from [0244] onward.

  Of the above, alkylene glycol monoalkyl ether carboxylates and alkylene glycol monoalkyl ethers are preferred.

These solvents may be used alone or in combination of two or more. When mixing 2 or more types, it is preferable to mix the solvent which has a hydroxyl group, and the solvent which does not have a hydroxyl group. The mass ratio of the solvent having a hydroxyl group and the solvent having no hydroxyl group is from 1/99 to 99/1, preferably from 10/90 to 90/10, and more preferably from 20/80 to 60/40.
The solvent having a hydroxyl group is preferably an alkylene glycol monoalkyl ether, and the solvent having no hydroxyl group is preferably an alkylene glycol monoalkyl ether carboxylate.
The total solid content concentration in the resist composition is preferably 2.0 to 4.0% by mass, more preferably 2.0 to 3.0% by mass.

<Surfactant>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention preferably further contains a surfactant. As the surfactant, fluorine-based and / or silicon-based surfactants are preferable.
Surfactants corresponding to these include Megafac F176, Megafac R08 manufactured by Dainippon Ink and Chemicals, PF656, PF6320 manufactured by OMNOVA, Troisol S-366 manufactured by Troy Chemical, Sumitomo 3M Examples include Fluorad FC430 manufactured by Co., Ltd., polysiloxane polymer KP-341 manufactured by Shin-Etsu Chemical Co., Ltd., and the like.
Further, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. More specific examples include polyoxyethylene alkyl ethers and polyoxyethylene alkyl aryl ethers.

  In addition, known surfactants can be used as appropriate. Examples of the surfactant that can be used include those described in [0273] et seq. Of US Patent Application Publication No. 2008/0248425.

Surfactants may be used alone or in combination of two or more.
The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total solid content of the actinic ray-sensitive or radiation-sensitive resin composition.

<Acid-decomposable dissolution inhibiting compound>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is a dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter referred to as “dissolution inhibiting compound”) that decomposes by the action of an acid and increases the dissolution rate in an alkali developer. May also be included).
The dissolution inhibiting compound is preferably an alicyclic or aliphatic compound containing an acid-decomposable group, such as a cholic acid derivative containing an acid-decomposable group described in Proceeding of SPIE, 2724, 355 (1996). . Examples of the acid-decomposable group and alicyclic structure are the same as those described for the acid-decomposable resin.
When the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is irradiated with an electron beam or EUV light, it preferably contains a structure in which the phenolic hydroxyl group of the phenol compound is substituted with an acid-decomposable group. As a phenol compound, what contains 1-9 phenol frame | skeleton is preferable, More preferably, it contains 2-6 pieces.

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

  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.

  The preferable addition amount of these dissolution promoting compounds is 0 to 50% by mass, more preferably 0 to 30% by mass with respect to the acid-decomposable resin. 50 mass% or less is preferable at the point of development residue suppression and the pattern deformation prevention at the time of image development.

  Such phenol 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 and European Patent 219294. Can be easily synthesized.

  Further, compounds having a proton acceptor functional group described in JP-A No. 2006-208781 and JP-A No. 2007-286574 are also used for the actinic ray-sensitive or radiation-sensitive resin composition of the present invention. Can be suitably used.

<Pattern formation method>
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is applied on a support such as a substrate to form a resist film. The thickness of the resist film is preferably 0.02 to 0.1 μm.

  As a method of coating on the substrate, spin coating is preferable, and the rotation speed is preferably 1000 to 3000 rpm.

  For example, an actinic ray-sensitive or radiation-sensitive resin composition is applied to a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate application method such as a spinner or a coater. Dry to form a resist film. In addition, a known antireflection film can be applied in advance.

  The resist film is irradiated with actinic rays or radiation, preferably an electron beam (EB), X-ray or EUV light, usually through a mask, preferably baked (heated) and developed. Thereby, a good pattern can be obtained.

As the alkali developer in the development step, a quaternary ammonium salt typified by tetramethylammonium hydroxide is usually used, but other alkalis such as inorganic alkalis, primary to tertiary amines, alcohol amines and cyclic amines are also used. An aqueous solution can also be used.
Further, an appropriate amount of alcohol or surfactant may be added 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 Hereinafter, although an Example demonstrates this invention still in detail, the content of this invention is not limited by this.

Synthesis Example 1 (Synthesis of Monomer (M-1))
In 80 parts by mass of ethyl acetate, 10 parts by mass of p-hydroxystyrene and 0.01 parts by mass of p-toluenesulfonic acid / pyridine salt were dissolved at room temperature. While stirring this solution, a mixed solution of 10.7 parts by mass of cyclohexyl vinyl ether and 20 parts by mass of ethyl acetate was added dropwise at room temperature. After dropping, the reaction was further allowed to proceed at room temperature for 24 hours.
Triethylamine was added to the reaction solution to make it basic, and after washing with ion-exchanged water, the organic layer was concentrated and purified by column chromatography with hexane / ethyl acetate to obtain 12.3 parts by mass of the following monomer (M-1 )

Synthesis Example 2 (Synthesis of monomer (M-2))
In Synthesis Example 1, the reaction was conducted in the same manner as in Synthesis Example 1 except that 13.1 parts by mass of 2-cyclohexylethyl vinyl ether was used instead of cyclohexyl vinyl ether, and 14.7 parts by mass of the following monomer (M-2) was added. Obtained.

Synthesis Example 3 (Synthesis of monomer (M-3))
In Synthesis Example 1, the reaction was conducted in the same manner as in Synthesis Example 1 except that 20.9 parts by mass of 2- (4-cyclohexylphenoxy) ethyl vinyl ether was used instead of cyclohexyl vinyl ether, and 19.3 masses of the following monomer (M -3) was obtained.

Synthesis Example 4 (Synthesis of monomer (M-4))
In Synthesis Example 1, the reaction was carried out in the same manner as in Synthesis Example 1 except that 7.2 parts by mass of dihydropyran was used instead of cyclohexyl vinyl ether to obtain 10.4 parts by mass of the following monomer (M-4).

Synthesis Example 5 (Synthesis of monomer (M-5))
In Synthesis Example 1, 15.3 parts by mass of 6-endo-hydroxy-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-lactone-5-exo-vinyl ether was used instead of cyclohexyl vinyl ether. The reaction was carried out in the same manner as in Synthesis Example 1 to obtain 15.3 parts by mass of the following monomer (M-5).

Synthesis Example 6 (Synthesis of monomer (M-6))
10 parts by mass of 4-hydroxystyrene was dissolved in 100 parts by mass of tetrahydrofuran, 21.8 parts by mass of di-tert-butyl dicarbonate and 0.1 part by mass of dimethylaminopyridine were added, and reacted at room temperature for 24 hours. Ethyl acetate was added to the reaction solution, washed and concentrated with water, and purified by column chromatography with hexane / ethyl acetate to obtain 12.8 parts by mass of the following monomer (M-6).

Synthesis Example 7 (Synthesis of monomer (M-7))
50 parts by mass of triphenylsulfonium Br salt was dissolved in 50 parts by mass of methanol. To this liquid, a mixed liquid of 30 parts by mass of 4-styrenesulfonic acid Na salt, 50 parts by mass of methanol, and 130 parts by mass of ion-exchanged water was added dropwise with stirring at room temperature.
Extraction and washing were performed by adding ion-exchanged water and chloroform. After concentrating the organic layer, the precipitated solid was reslurried in hexane / ethyl acetate and filtered to obtain 48 parts by mass of the following monomer (M-7).

Synthesis Example 8 (Synthesis of monomer (M-8))
19.6 parts by mass of 4-hydroxybenzenesulfonic acid triphenylsulfonium salt is dissolved in 80 parts by mass of N-methylpyrrolidone, 8.2 parts by mass of 4-chloromethylstyrene, 18.7 parts by mass of potassium carbonate, and tetramethylammonium. 0.006 part by mass of bromide was added, and the reaction was performed at 80 ° C. for 3 hours. After precipitating with ethyl acetate, it was dissolved in chloroform, washed with water and concentrated to obtain 20 parts by mass of the following monomer (M-8).

Synthesis Example 9 (Synthesis of monomer (M-9))
10 parts by weight of methacrylic acid is dissolved in 100 parts by weight of tetrahydrofuran, 39.0 parts by weight of 1,1,1,3,3,3-hexafluoroisopropanol, 28.7 parts by weight of dicyclohexylcarbodiimide, and 0.1% of dimethylaminopyridine. Mass parts were added and reacted at room temperature for 24 hours. Ethyl acetate was added to the reaction solution, washed with water, concentrated, and purified by column chromatography with hexane / ethyl acetate to obtain 16.4 parts by mass of the following monomer (M-9).

Synthesis Example 10 (Synthesis of monomer (M-10))
14.8 parts by mass of 5-exo-hydroxy-6-endo-hydroxy-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-lactone is dissolved in 100 parts by mass of tetrahydrofuran, and methacrylic acid chloride 12 Part by mass and 11.6 parts by mass of triethylamine were added dropwise and reacted at room temperature for 3 hours. Ethyl acetate was added to the reaction solution, washed with water, concentrated, and purified by column chromatography with hexane / ethyl acetate to obtain 12.8 parts by mass of the following monomer (M-10).

Synthesis Example 11 (Synthesis of Monomer (M-11))
In Synthesis Example 10, instead of 5-exo-hydroxy-6-endo-hydroxy-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-lactone, hexahydro-3-hydroxyisobenzofuran-1 ( The reaction was conducted in the same manner as in Synthesis Example 10 except that 15.0 parts by mass of 3H) -one was used to obtain 12.9 parts by mass of the following monomer (M-11).

Synthesis Example 12 (Synthesis of monomer (M-12))
28.6 parts by mass of 6-endo-carboxylic acid-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-anhydride-5-exo-chloromethyl ester are dissolved in 100 parts by mass of tetrahydrofuran. Then, 10 parts by mass of methacrylic acid and 11.7 parts by mass of triethylamine were added and reacted at 40 degrees for 6 hours. Ethyl acetate was added to the reaction solution, washed with water, concentrated, and purified by column chromatography with hexane / ethyl acetate to obtain 20.6 parts by mass of the following monomer (M-12).

Synthesis Example 13 (Synthesis of Monomer (M-13))
In Synthesis Example 12, 6-endo-amino-bicyclo instead of 6-endo-carboxylic acid-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-anhydride-5-chloromethyl ester The same as Synthesis Example 12 except that 29.5 parts by mass of [2,2,1] heptane-2-endo-carboxylic acid-Y-amido-2-oxo-cyano-5-exo-chloromethyl ester was used. To give 21.2 parts by mass of the following monomer (M-13).

Synthesis Example 14 (Synthesis of monomer (M-14))
In Synthesis Example 12, 6-endo-hydroxy-bicyclo instead of 6-endo-carboxylic acid-bicyclo [2,2,1] heptane-2-endo-carboxylic acid-Y-anhydride-5-chloromethyl ester The same as Synthesis Example 12 except that 29.7 parts by mass of [2,2,1] heptane-2-endo-carboxylic acid-Y-lactone-2-oxo-cyano-5-exo-chloromethyl ester was used. To obtain 21.2 parts by mass of the following monomer (M-14).
Similarly, monomers (M-15) and (M-16) were also obtained.

Synthesis Example 15 (Synthesis of Resin (P-1))
4.66 parts by mass of 1-methoxy-2-propanol was heated to 80 ° C. under a nitrogen stream. While stirring this liquid, 2.98 parts by mass of 4-hydroxystyrene (hereinafter also referred to as “HOST”), 1.74 parts by mass of the monomer (M-6) obtained in Synthesis Example 6 above, and the above synthesis example Monomer (M-7) 0.35 parts by mass obtained in Example 7, Monomer (M-9) 0.15 parts by mass obtained in Synthesis Example 9 above, 18.6 parts by mass of 1-methoxy-2-propanol Then, a mixed solution of 1.36 parts by mass of dimethyl 2,2′-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] was added dropwise over 2 hours. After completion of dropping, the mixture was further stirred at 80 ° C. for 4 hours. The reaction solution was allowed to cool and then reprecipitated with a large amount of hexane / ethyl acetate and vacuum dried to obtain 3.98 parts by mass of the resin (P-1) of the present invention.
The weight average molecular weight (Mw: polystyrene conversion) determined from GPC (carrier: N-methyl-2-pyrrolidone (NMP)) of the obtained resin was Mw = 15100, Mw / Mn (hereinafter also referred to as “MWD”). = 1.72.

Synthesis Examples 16 to 21 (Synthesis of Resins (P-2) to (P-7))
Hereinafter, in the same manner as in Synthesis Example 15, resins (P-2) to (P-7) used in the present invention were synthesized.
The structural units used, their charge (molar ratio), weight average molecular weight, number average molecular weight, and dispersity (MWD) are shown in Table 1 below.

  In addition, comparative resins P-8 to P-10 were synthesized. P-8 was synthesized in accordance with the method described in US Patent Application Publication No. 2006/0121390. P-9 was synthesized according to the method described in Japanese Patent No. 3613491. P-10 was synthesized according to the method described in Japanese Patent No. 4145075.

[Examples 1-7 and Comparative Examples 1-3]
<Preparation of resist composition>
It is dissolved in the mixed solvent shown in Table 1, and this is filtered through a polytetrafluoroethylene filter having a pore size of 0.1 μm to prepare a 2.5% total solid content (mass%) positive resist solution. Evaluation was performed as follows.
In addition, for all the prescriptions, separately from the components in the table, surfactant Megafac R08 (manufactured by Dainippon Ink & Chemicals, Inc.) was added so as to be 0.05% by mass with respect to the total solid content. . Moreover, about Example 4, 5, tetrabutylammonium hydroxide was further added so that it might become 1.5 mass% with respect to the total solid.

<Resist evaluation (EB)>
The prepared positive resist solution is uniformly coated on a silicon substrate that has been subjected to hexamethyldisilazane treatment using a spin coater, and is heated and dried on a hot plate at 120 ° C. for 90 seconds to form a resist having a film thickness of 100 nm. A film was formed.
This resist film was irradiated with an electron beam using an electron beam irradiation apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage: 50 keV). Immediately after irradiation, it was heated on a hot plate at 110 ° C. for 90 seconds. Furthermore, development was performed at 23 ° C. for 60 seconds using an aqueous tetramethylammonium hydroxide solution having a concentration of 2.38% by mass, rinsed with pure water for 30 seconds, and then dried to form a line and space pattern. Was evaluated by the following method. The results are shown in the table below.

〔sensitivity〕
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.). Sensitivity was defined as the minimum irradiation energy when resolving a 100 nm line (line: space = 1: 1).

[Resolution]
The resolving power was defined as the limiting resolving power (minimum line width at which lines and spaces were separated and resolved) at the irradiation dose showing the above sensitivity.

[Line edge roughness (LER)]
The distance from the reference line where there should be an edge, using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.) for any 30 points in the length direction 50 μm of the 100 nm line pattern at the irradiation amount showing the sensitivity described above. Was measured to obtain a standard deviation, and 3σ (nm) was calculated.

[Exposure latitude (EL)]
EL is represented by a change rate (%) of the exposure amount required for changing the line width by 10% based on the line width of 100 nm in the line-and-space one-to-one exposure.

  In the table, each abbreviation represents the resin or the following.

From the results shown in Table 2, the composition of the present invention has a good balance between sensitivity and EL (this is apparent from the “EL / sensitivity” section in the table), and has high sensitivity, high resolution, and good quality. It was found that the line edge roughness was satisfied at the same time.
Similar effects can be obtained in EUV and X-ray lithography.

Claims (10)

A repeating unit (a) having a structure in which an acid anion is generated by irradiation with an actinic ray or radiation on a side chain of the resin,
A repeating unit (b) having a protected phenolic hydroxyl group, and
A repeating unit (x) having a group that decomposes under the action of an alkali developer and increases the dissolution rate in the alkali developer,
Actinic ray-sensitive or radiation-sensitive resin composition comprising a resin (P) containing Resin (P) contains at least 1 type of repeating unit selected from the following general formula (III)-(V) as said repeating unit (a), The activity sensitivity of Claim 1 characterized by the above-mentioned. A light-sensitive or radiation-sensitive resin composition.

In general formulas (III) to (V),
A represents a structural site that decomposes upon irradiation with actinic rays or radiation to generate an acid anion.
R ₀₄ , R ₀₅ and R _{07 to} R ₀₉ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
R ₀₆ represents a cyano group, a carboxyl group, —CO—OR ₂₅ or —CO—N (R ₂₆ ) (R ₂₇ ). R ₂₆ and R ₂₇ may combine to form a ring with the nitrogen atom.
R ₀₆ and X ₂ may be linked to each other to form a ring.
X _{1 to} X ₃ are each independently a single bond, an arylene group, an alkylene group, a cycloalkylene group, —O—, —SO ₂ —, —CO—, —N (R ₃₃ ) —, or a combination thereof. Represents a divalent linking group.
R ₂₅ represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.
R ₂₆ , R ₂₇ and R ₃₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group.   The actinic ray-sensitive or radiation-sensitive resin composition according to claim 2, wherein A in the general formulas (III) to (V) is a structural portion containing a sulfonium salt structure or an iodonium salt structure. . The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the repeating unit (b) is a repeating unit represented by the following general formula (I).

In general formula (I),
R ₀₁ , R ₀₂ and R ₀₃ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. R ₀₃ represents an alkylene group and may be bonded to Ar ₁ to form a 5-membered or 6-membered ring.
Ar ₁ represents an n + 1 valent aromatic ring group.
n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of Y represents a group capable of leaving by the action of an acid.
n represents an integer of 1 to 4. The actinic ray-sensitive or radiation-sensitive resin according to claim 4, wherein the group capable of leaving by the action of an acid of Y in the general formula (I) is represented by the following general formula (II): Composition.

In general formula (II),
L ₁ and L ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alkyl group, a cycloalkyl group, an alicyclic group which may contain a hetero atom, an aromatic ring group which may contain a hetero atom, an amino group, an ammonium group, a mercapto group, a cyano group or an aldehyde group. .
At least two of Q, M, and L ₁ may combine to form a ring.   The group in which the repeating unit (x) has a partial structure which is decomposed by the action of an alkali developer and increases the dissolution rate in the alkali developer has a lactone structure, a cyclic amide structure, or a cyclic acid anhydride structure. The actinic ray-sensitive or radiation-sensitive resin composition according to any one of claims 1 to 5.   The actinic ray-sensitive or radiation-sensitive resin composition according to claim 6, wherein the group that decomposes under the action of an alkali developer and increases the dissolution rate in the alkali developer is a group having a lactone structure. object.   The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the composition is for electron beam, X-ray or EUV light.   A pattern forming method comprising a step of forming a resist film using the composition according to claim 1, exposing and developing.   The pattern forming method according to claim 9, wherein the exposure is performed using an electron beam, an X-ray, or EUV light.