JP2006091658A - Positive resist composition for electron beam, euv or x-ray, and method for forming pattern by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition having preferable sensitivity, resolution and a pattern profile, small line edge roughness and preferable dissolution contrast, for forming a pattern with electron beams, EUV rays (extreme ultraviolet at near 13 nm wavelength) or X-rays, and to provide a method for forming a pattern by using the composition. <P>SOLUTION: The positive resist composition for electron beams, EUV rays or X-rays is provided which contains: (A) a cyclic compound having four or more phenolic structures; (B) a resin which has a repeating unit of a specified structure, the solubility of which with an alkali developer solution increases by the effect of an acid; (C) and a compound which generates an acid by irradiation with active rays or radiation. The method for forming a pattern by using the above composition is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a positive resist composition for electron beam, EUV or X-ray used for manufacturing semiconductor integrated circuit elements, integrated circuit manufacturing masks, and the like, and a pattern forming method using the same.

  A chemically amplified positive resist composition known as a positive photoresist composition generates an acid in an exposed area by irradiation with actinic rays or radiation such as far ultraviolet light, and is activated by a reaction using this acid as a catalyst. It is a pattern forming material for changing the solubility of a light or radiation irradiated portion and a non-irradiated portion in a developing solution to form a pattern on a substrate.

  The chemically amplified positive resist composition comprises an alkali-soluble resin, a compound that generates an acid upon exposure to actinic rays or radiation (a photoacid generator), and a dissolution-inhibiting compound for an alkali-soluble resin having an acid-decomposable group. A three-component system comprising a resin having a group that decomposes by reaction with an acid and becomes alkali-soluble and a photoacid generator, and a resin having a group that decomposes by reaction with an acid and becomes alkali-soluble And a hybrid system comprising a low-molecular dissolution inhibiting compound having an acid-decomposable group and a photoacid generator.

Conventionally, various improvements have been attempted on resist compositions.
For example, Patent Document 1 (Japanese Patent Laid-Open No. 2003-321423) and Patent Document 2 (Japanese Patent Laid-Open No. 2002-328473) describe a positive resist composition containing calixarene having a t-butoxycarbonylalkyl group. Has been.
Patent Document 3 (US Pat. No. 6,093,517) describes a positive resist composition containing calixarene.

However, when a conventional resist composition is used as an electron beam resist, it has been desired to improve the pattern shape, sensitivity, resolution, and line edge portion shape (line edge roughness).
In addition, in pattern formation by EUV irradiation, improvement in dissolution contrast as well as high sensitivity has been desired.

JP 2003-321423 A JP 2002-328473 A US Pat. No. 6,093,517

  The object of the present invention is to form an electron beam, EUV (Extreme Ultraviolet: wavelength of around 13 nm) or X-ray pattern formation with good sensitivity, resolving power and pattern shape, low line edge roughness, and further in EUV irradiation. Another object of the present invention is to provide a positive resist composition having good sensitivity and dissolution contrast and a pattern forming method using the same.

  The present invention has the following configuration.

(1) (A) a cyclic compound having four or more phenol structures,
(B) A resin having a repeating unit represented by the following general formula (B1) and / or (B2), which has increased solubility in an alkali developer by the action of an acid, and (C) irradiation with actinic rays or radiation. A positive resist composition for electron beam, EUV or X-ray, comprising a compound capable of generating an acid.

In general formulas (B1) and (B2),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, or an acyloxy group. When there are a plurality of Zs, the plurality of Zs may be the same or different.
A ₁ represents a group containing a cyclic carbon structure and decomposing by the action of an acid. A ₁ is, when a plurality, the plurality is A ₁ may be the same or different.
Ra represents a hydrogen atom, a methyl group, a halogen atom, a cyano group or a CF ₃ group.
Re represents a group that is decomposed by the action of an acid.
m represents an integer of 1 to 3.
n represents an integer of 0 to 2.

  (2) The positive type for electron beam, EUV or X-ray according to (1), wherein the cyclic compound of component (A) is a compound having a repeating unit represented by the following general formula (C1) Resist composition.

In general formula (C1),
G represents a divalent linking group.
p represents an integer of 1 to 3.
q represents an integer of 4 to 10.

(3) The group which decomposes by the action of an acid represented by A ₁ has a structure represented by the following general formula (X1) or (X2), (1) or (2) A positive resist composition for electron beam, EUV or X-ray.

In general formula (X1),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.
r represents an integer of 0 to 20.

In general formula (X2),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
W represents a divalent linking group.
Y represents a group selected from —O—, —OCO—, —COO—, —O—CH ₂ —, —NHCO—, —CONH—, —S—, —SO ₂ — and —SO ₃ —.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.

  (4) (C) A compound that generates an acid upon irradiation with actinic rays or radiation is contained in the total solid content of the resist composition in a range of 6 to 20% by mass (1) to ( The positive resist composition for electron beam, EUV or X-ray according to any one of 3).

  (5) The positive resist composition for electron beam, EUV or X-ray according to any one of (1) to (4), further comprising (D) an organic basic compound.

  (6) A step of forming a resist film from the positive resist composition according to any one of (1) to (5), exposing the resist film with an electron beam, EUV, or X-ray, and then heating and developing the resist film. A pattern forming method comprising:

  According to the present invention, it is possible to provide a positive resist composition that is excellent in sensitivity and resolving power with respect to pattern formation by electron beam, EUV or X-ray irradiation, and further excellent in pattern shape, line edge roughness, and dissolution contrast.

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 has a substituent with what does not have 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).

[1] (A) Cyclic compound having four or more phenol structures The positive resist composition of the present invention is a cyclic compound having four or more phenol structures (hereinafter referred to as “cyclic compound (A)”). (Also called).

The phenol structure is preferably a structure having one benzene ring and two or more phenolic hydroxyl groups from the viewpoint of solubility in an alkaline developer.
There may be four or more phenol structures, all of which may be the same or different from each other.

  The cyclic compound (A) has a structure in which there are four or more phenol structures connected by a linking group, and has a linear or branched alkyl group or cycloalkyl group having 1 to 15 carbon atoms in the benzene ring or the linking group. Is preferable from the viewpoint of organic solvent solubility.

  The cyclic compound (A) is preferably a compound having a repeating unit represented by the following general formula (C1).

In general formula (C1),
G represents a divalent linking group.
p represents an integer of 1 to 3.
q represents an integer of 4 to 10.

  The cyclic compound (A) is preferably a compound represented by the following general formula (C2).

  G, p and q in the general formula (C2) have the same meanings as G, p and q in the general formula (C1).

The divalent linking group of G in the general formulas (C1) and (C2) has at least one linear or branched alkyl group (preferably having 1 to 15 carbon atoms) or a cycloalkyl group (preferably as a substituent). Is preferably a methylene group having 3 to 15).
In addition to the hydroxyl group, the benzene ring in the general formulas (C1) and (C2) may further have a substituent. Examples of the substituent that the benzene ring may have include, for example, a linear or branched alkyl group having 1 to 15 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, a linear or branched chain having 1 to 15 carbon atoms. Or a cyclic alkoxy group etc. can be mentioned.

  Specific examples of the cyclic compound (A) are shown below, but the present invention is not limited thereto.

[2] (B) Resin having a repeating unit represented by the general formula (B1) and / or (B2) and having increased solubility in an alkali developer by the action of an acid. , A resin having a repeating unit represented by the general formula (B1) and / or (B2), whose solubility in an alkaline developer is increased by the action of an acid (hereinafter also referred to as “acid-decomposable resin (B)”) ).

In general formulas (B1) and (B2),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, or an acyloxy group. When there are a plurality of Zs, the plurality of Zs may be the same or different.
A ₁ represents a group containing a cyclic carbon structure and decomposing by the action of an acid. A ₁ is, when a plurality, the plurality is A ₁ may be the same or different.
Ra represents a hydrogen atom, a methyl group, a halogen atom, a cyano group or a CF ₃ group.
Re represents a group that is decomposed by the action of an acid.
m represents an integer of 1 to 3.
n represents an integer of 0 to 2.

In the general formula (B1), the group containing the cyclic carbon structure of A ₁ and decomposable by the action of an acid (hereinafter also referred to as “acid-decomposable group”) is, for example, —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ), —COO—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (R ₀₁ ) (R ₀₂ ) (OR ₃₉ ), -C (R ₀₁ ) (R ₀₂ ) COO-C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ) and the like.
R _{36 to} R ₃₉ each independently represents an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. Represents an aralkyl group which may have a substituent or an aryl group which may have a substituent. R ₃₆ and R ₃₉ may be bonded to each other to form a ring.
R ₀₁ and R ₀₂ are each independently a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an alkenyl group which may have a substituent. Represents an aralkyl group which may have a substituent or an aryl group which may have a substituent.
Provided that at least one of R ₃₆ , R ₃₇ and R ₃₈ , at least one of R ₃₆ , R ₃₇ and R ₃₉ , and at least one of R ₀₁ , R ₀₂ and R ₃₉ are cyclic carbon Includes structure.

As the alkyl group for R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ , an alkyl group having 1 to 8 carbon atoms is preferable. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, A hexyl group, 2-ethylhexyl group, an octyl group, etc. can be mentioned.
The cycloalkyl group for 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 cyclopentyl group, a cyclohexyl group, a cyclobutyl 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, tetocyclo A dodecyl group, an androstanyl group, etc. can be mentioned. 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 and R ₀₂ is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, tolyl group, dimethylphenyl group, 2,4,6-trimethylphenyl group. Naphthyl group, anthryl group, 9,10-dimethoxyanthryl group, and the like.
As the aralkyl group of R _{36 to} R ₃₉ , R ₀₁ and R _02, an aralkyl group having 7 to 12 carbon atoms is preferable, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.
The alkenyl group represented by 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.
Examples of the substituent that R _{36 to} R ₃₉ , R ₀₁ and R ₀₂ may have include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, a hydroxy group, and a carboxy group. , Halogen atoms, alkoxy groups, thioether groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, cyano groups, nitro groups, and the like.

Particularly preferred are those represented by the following general formula (X1) or general formula (X2).

In general formula (X1),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.
r represents an integer of 0 to 20.

In general formula (X2),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
W represents a divalent linking group.
Y represents a group selected from —O—, —OCO—, —COO—, —O—CH ₂ —, —NHCO—, —CONH—, —S—, —SO ₂ — and —SO ₃ —.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.

The alkyl group as R ₁ and R ₂ in the general formula (X1) is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and n-butyl. Group, isobutyl group, sec-butyl group, t-butyl group and the like.
At least one of R ₁ and R ₂ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

The alkyl group as R ₃ and R ₄ may be linear or branched. As a linear alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, for example, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl. Group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group and the like. As a branched alkyl group, Preferably it is C3-C30, More preferably, it is 3-20, for example, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, Examples include i-hexyl group, t-hexyl group, i-heptyl group, t-heptyl group, i-octyl group, t-octyl group, i-nonyl group, t-decanoyl group and the like.
The cycloalkyl group as R ₃ and R ₄ preferably has 3 to 30 carbon atoms, more preferably 3 to 20, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl. Group, cyclononyl group, cyclodecanoyl group and the like.

  As an aryl group of Za in general formula (X1), Preferably it is C6-C30, More preferably, it is C6-C20, for example, a phenyl group, 4-methylphenyl group, 3-methylphenyl group, 2 -Methylphenyl group, 4-ethylphenyl group, 3-ethylphenyl group, 2-ethylphenyl group, 4-n-propylphenyl group, 3-n-propylphenyl group, 2-n-propylphenyl group, 4-i -Propylphenyl group, 3-i-propylphenyl group, 2-i-propylphenyl group, 4-cyclopropylphenyl group, 3-cyclopropylphenyl group, 2-cyclopropylphenyl group, 4-n-butylphenyl group, 3-n-butylphenyl group, 2-n-butylphenyl group, 4-i-butylphenyl group, 3-i-butylphenyl group, 2-i-butyl Phenyl group, 4-t-butylphenyl group, 3-t-butylphenyl group, 2-t-butylphenyl group, 4-cyclobutylphenyl group, 3-cyclobutylphenyl group, 2-cyclobutylphenyl group, 4- Cyclopentylphenyl group, 4-cyclohexylphenyl group, 4-cycloheptenylphenyl group, 4-cyclooctanylphenyl group, 2-cyclopentylphenyl group, 2-cyclohexylphenyl group, 2-cycloheptenylphenyl group, 2-cycloocta Nylphenyl, 3-cyclopentylphenyl, 3-cyclohexylphenyl, 3-cycloheptenylphenyl, 3-cyclooctanylphenyl, 4-cyclopentyloxyphenyl, 4-cyclohexyloxyphenyl, 4-cyclohept Tenyloxyphenyl group, 4-cyclo Tanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl Group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentylphenyl group, 4-n-hexylphenyl group, 4-n-heptenylphenyl group, 4-n-octa Nylphenyl group, 2-n-pentylphenyl group, 2-n-hexylphenyl group, 2-n-heptenylphenyl group, 2-n-octanylphenyl group, 3-n-pentylphenyl group, 3-n- Hexylphenyl group, 3-n-heptenylphenyl group, 3-n-octanylphenyl Group, 2,6-di-isopropylphenyl group, 2,3-di-isopropylphenyl group, 2,4-di-isopropylphenyl group, 3,4-di-isopropylphenyl group, 3,6-di-t- Butylphenyl group, 2,3-di-t-butylphenyl group, 2,4-di-t-butylphenyl group, 3,4-di-t-butylphenyl group, 2,6-di-n-butylphenyl Group, 2,3-di-n-butylphenyl group, 2,4-di-n-butylphenyl group, 3,4-di-n-butylphenyl group, 2,6-di-i-butylphenyl group, 2,3-di-i-butylphenyl group, 2,4-di-i-butylphenyl group, 3,4-di-i-butylphenyl group, 2,6-di-t-amylphenyl group, 2, 3-di-t-amylphenyl group, 2,4-di-t-amylphenyl group, 3,4- -T-amylphenyl group, 2,6-di-i-amylphenyl group, 2,3-di-i-amylphenyl group, 2,4-di-i-amylphenyl group, 3,4-di-i -Amylphenyl group, 2,6-di-n-pentylphenyl group, 2,3-di-n-pentylphenyl group, 2,4-di-n-pentylphenyl group, 3,4-di-n-pentyl Phenyl group, 4-adamantylphenyl group, 2-adamantylphenyl group, 4-isoboronylphenyl group, 3-isoboronylphenyl group, 2-isobornylphenyl group, 4-cyclopentyloxyphenyl group, 4-cyclohexyloxy Phenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, -Cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4 -N-pentyloxyphenyl group, 4-n-hexyloxyphenyl group, 4-n-heptenyloxyphenyl group, 4-n-octanyloxyphenyl group, 2-n-pentyloxyphenyl group, 2-n- Hexyloxyphenyl group, 2-n-heptenyloxyphenyl group, 2-n-octanyloxyphenyl group, 3-n-pentyloxyphenyl group, 3-n-hexyloxyphenyl group, 3-n-heptenyloxy Phenyl group, 3-n-octanyloxyphenyl group, 2,6-di-isopropyl Oxyphenyl group, 2,3-di-isopropyloxyphenyl group, 2,4-di-isopropyloxyphenyl group, 3,4-di-isopropyloxyphenyl group, 2,6-di-t-butyloxyphenyl group, 2,3-di-t-butyloxyphenyl group, 2,4-di-t-butyloxyphenyl group, 3,4-di-t-butyloxyphenyl group, 2,6-di-n-butyloxyphenyl group Group, 2,3-di-n-butyloxyphenyl group, 2,4-di-n-butyloxyphenyl group, 3,4-di-n-butyloxyphenyl group, 2,6-di-i-butyl Oxyphenyl group, 2,3-di-i-butyloxyphenyl group, 2,4-di-i-butyloxyphenyl group, 3,4-di-i-butyloxyphenyl group, 2,6-di-t -Amyloxyphenyl group, 2 3-di-t-amyloxyphenyl group, 2,4-di-t-amyloxyphenyl group, 3,4-di-t-amyloxyphenyl group, 2,6-di-i-amyloxyphenyl group, 2,3-di-i-amyloxyphenyl group, 2,4-di-i-amyloxyphenyl group, 3,4-di-i-amyloxyphenyl group, 2,6-di-n-pentyloxyphenyl Group, 2,3-di-n-pentyloxyphenyl group, 2,4-di-n-pentyloxyphenyl group, 3,4-di-n-pentyloxyphenyl group, 4-adamantyloxyphenyl group, 3- Adamantyloxyphenyl group, 2-adamantyloxyphenyl group, 4-isoboronyloxyphenyl group, 3-isoboronyloxyphenyl group, 2-isoboronyloxyphenyl group and the like. It may be further substituted.

  The cycloalkyl group of Za may be monocyclic, polycyclic, or bridged. For example, the cycloalkyl group may have a bridged structure. Moreover, these groups may have a substituent. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyls may have a substituent. Specific examples of the alicyclic structure of the cycloalkyl group include cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane, and the following structures.

Preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin group, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecanyl group. And cyclododecanyl group. More preferred are an adamantyl group, a decalin group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, and a tricyclodecanyl group.

  Examples of the substituents of these alicyclic structures include alkyl groups, aryl groups, aralkyl groups, halogen atoms, hydroxyl groups, alkoxy groups, carboxyl groups, and alkoxycarbonyl groups. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. The aryl group is preferably an aryl group having 6 to 14 carbon atoms. For example, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a biphenyl residue (a group formed by losing one hydrogen atom from a biphenyl group) And p-terphenyl residue (a group formed by losing one hydrogen atom from a p-terphenyl group). The aralkyl group 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. Preferred examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the substituent that the alkyl group, aryl group, aralkyl group, and alkoxy group may have include a hydroxyl group, a halogen atom, and an alkoxy group (preferably having 1 to 4 carbon atoms).

  The substituent that the alicyclic structure of the cycloalkyl group of Za may have is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl having 7 to 20 carbon atoms. It is a group. These substituents may further have a substituent.

  Specific examples of the group represented by the general formula (X1) are shown below, but are not limited thereto.

In general formula (X2),
The alkyl group as R ₁ and R ₂ are the same alkyl group as R ₁ and R ₂ in the general formula (X1) and the like.
The divalent linking group as W preferably has 1 to 10 carbon atoms, and includes, for example, a linear, branched or cyclic alkylene group, an arylene group, a heteroarylene group, an aralkylene group, and —S—, —C. (═O) —, —N (R ₇ ) —, —SO—, —SO ₂ —, —CO ₂ —, —N (R ₇ ) SO ₂ — or a divalent combination of two or more of these groups The group can be mentioned. Here, R ₇ can include a hydrogen atom or an alkyl group (specific examples of the alkyl group include those similar to the above R ₁ ).

  Za in the general formula (X2) has the same meaning as Za in the general formula (X1).

In the general formula (X2), at least _one of R ₁ and R ₂ is preferably a linear or branched alkyl group having 2 to 4 carbon atoms.

  Specific examples of the group represented by the general formula (X2) are shown below, but are not limited thereto.

In the general formula (B1), examples of the halogen atom for Z include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The acyl group of Z is preferably an acyl group having 1 to 8 carbon atoms, and examples thereof include a formyl group, an acetyl group, a propionyl group, a butyryl group, a valeryl group, a pivaloyl group, and a benzoyl group.
The acyloxy group of Z is preferably an acyloxy group having 2 to 8 carbon atoms. For example, an acetoxy group, a propionyloxy group, a butyllyoxy group, a valeryloxy group, a pivaloyloxy group, a hexanoyloxy group, an octanoyloxy group, a benzoyloxy group, etc. Can be mentioned.
Z may be further substituted with a halogen atom or the like.

  Specific examples of the repeating unit represented by formula (B1) are shown below, but are not limited thereto.

  In the general formula (B2), examples of the group that decomposes with an acid of Re include groups represented by the following general formula (pI) to general formula (pV).

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. A methyl group and an ethyl group are preferred. Further, at least one of R _{12 to} R ₁₄ , and any of R ₁₅ and R ₁₆ is preferably an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ is a fat Represents a cyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

Examples of the alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom include groups having a bicyclo, tricyclo, tetracyclo structure, and the like. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.

  Among the alicyclic hydrocarbon groups, examples of the structure of the alicyclic moiety include the same examples as the specific examples of the alicyclic structure given for the cycloalkyl group of Za in the general formula (X1). Can do.

  In the present invention, preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, and a cycloheptyl group. , Cyclooctyl group, cyclodecanyl group, and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, and a tricyclodecanyl group.

Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group.
Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The alkyl group and alkoxy group may further have a substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ may be substituted or unsubstituted, and is preferably linear or branched having 1 to 4 carbon atoms. It is an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. The alkyl group may further have a substituent. As further substituents for the alkyl group, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, carboxy group, An alkoxycarbonyl group, a nitro group, etc. can be mentioned.

  In the general formula (B2), examples of the halogen atom for Ra include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  From the viewpoint of little variation in pattern size during observation with a scanning electron microscope (SEM resistance), in the general formula (B2), a repeating unit in which Re is a group represented by the following is particularly preferable.

R ₂₆ and R ₂₇ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms.

  Hereinafter, although the specific example of the monomer corresponding to the repeating unit shown by general formula (B2) is given, this invention is not limited to this.

The acid-decomposable resin (B) may have another repeating unit together with the repeating unit represented by the general formula (B1) and / or (B2).
Examples of the repeating unit that the acid-decomposable resin (B) may further include a repeating unit of styrene. Styrene may have a substituent. Examples of the substituent that styrene may have include a hydroxyl group, a halogen atom, a cyano group, a nitro group, an alkyl group, an alkoxy group, an acyl group, and an acyloxy group.

In the acid-decomposable resin (B), the content of the repeating unit represented by the general formula (B1) is preferably 10 to 50 mol%, more preferably 15 to 30 mol%.
In the acid-decomposable resin (B), the content of the repeating unit represented by the general formula (B2) is preferably 10 to 45 mol%, and more preferably 20 to 35 mol%.

  Although the specific example of acid-decomposable resin (B) is shown below, this invention is not limited to this.

The acid-decomposable resin (B) can be obtained, for example, by synthesizing a corresponding vinyl ether and reacting it with a phenolic hydroxyl group-containing alkali-soluble resin dissolved in a suitable solvent such as tetrahydrofuran by a known method. The reaction is usually carried out in the presence of an acidic catalyst, preferably an acidic ion exchange resin, hydrochloric acid, p-toluenesulfonic acid, or a salt such as pyridinium tosylate. The corresponding vinyl ether can be synthesized from an active raw material such as chloroethyl vinyl ether by a method such as a nucleophilic substitution reaction or can be synthesized using a mercury or palladium catalyst.
As another method, it can also be synthesized by a method of acetal exchange using a corresponding alcohol and vinyl ether. In this case, the substituent to be introduced is given to the alcohol, the vinyl ether is mixed with a relatively unstable vinyl ether such as t-butyl vinyl ether, and the reaction is carried out in the presence of an acid such as p-toluenesulfonic acid or pyridinium tosylate. .

  As for the weight average molecular weight of acid-decomposable resin (B), 1500-80000 are preferable, More preferably, it is 2500-10000.

  Further, the dispersity (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.5, and particularly preferably 1.0 to 3.0. , Heat resistance and image formability (pattern profile, defocus latitude, etc.) are improved.

  The content of the acid-decomposable resin (B) in the solid content of the positive resist composition is preferably 30 to 99.99% by mass, and more preferably 40 to 99.97% by mass.

[3] (C) Compound that generates acid upon irradiation with actinic ray or radiation As a compound (acid generator) that generates acid upon irradiation with actinic ray or radiation that can be used in the present invention, photoinitiation of photocationic polymerization Used for photo-initiators, photo-initiators of radical photopolymerization, photo-decoloring agents for dyes, photo-discoloring agents, or micro-resist, preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, A known compound that generates an acid upon irradiation with an actinic ray or radiation such as KrF, ArF, F2 excimer laser, X-ray, electron beam, or a mixture thereof can be appropriately selected and used.

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

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

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

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1
~ 20.

Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (Z1-1), (Z1-2) and (Z1-3) described later.

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

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

Compound (Z1-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.

Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ is an aryl group and the remainder may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkyl or cycloalkylsulfonium compound, and an aryldialkyl or dicycloalkylsulfonium compound.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec. -A butyl group, a t-butyl group, etc. can be mentioned.

  The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms, and most preferably an alkyl group having 1 to 4 carbon atoms and 1 carbon atom. It is an alkoxy group of ~ 4. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Examples of the non-nucleophilic anion of X ⁻ 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. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic hydrocarbon group in the aliphatic sulfonate anion is preferably an alkyl group having 1 to 30 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, Examples thereof include an eicosyl group, and preferably a cycloalkyl group having 3 to 30 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

The alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent.
Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, and an alkylthio group.
Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
As the alkyl group, for example, preferably an alkyl group having 1 to 15 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group Hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc. it can.
As an alkoxy group, Preferably a C1-C5 alkoxy group, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned, for example.
As the alkylthio group, for example, preferably an alkylthio group having 1 to 15 carbon atoms, for example, methylthio group, ethylthio group, propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, pentylthio group, Neopentylthio group, hexylthio group, heptylthio group, octylthio group, nonylthio group, decylthio group, undecylthio group, dodecylthio group, tridecylthio group, tetradecylthio group, pentadecylthio group, hexadecylthio group, heptadecylthio group, octadecylthio group, nonadecylthio group Group, eicosylthio group and the like. The alkyl group, alkoxy group, and alkylthio group may be further substituted with a halogen atom (preferably a fluorine atom).

  Examples of the aliphatic hydrocarbon group in the aliphatic carboxylate anion include those similar to the aliphatic hydrocarbon group in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aromatic groups as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include aliphatic groups Examples thereof include the same halogen atom, alkyl group, alkoxy group and alkylthio group as in the sulfonate anion and aromatic sulfonate anion.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. These alkyl groups may have a substituent, and examples of the substituent include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, an alkylthio group, and the like, which are substituted with a fluorine atom. Alkyl groups are preferred.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

As the non-nucleophilic anion of X ⁻ , an aliphatic sulfonate anion substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group substituted with a fluorine atom A bis (alkylsulfonyl) imide anion and a tris (alkylsulfonyl) methide anion in which the alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion of X ⁻ is more preferably a fluorine-substituted aliphatic sulfonate anion having 4 to 8 carbon atoms, particularly preferably a nonafluorobutane sulfonate anion or a perfluorooctane sulfonate anion.

Next, the compound (Z1-2) will be described.
Compound (Z1-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an aliphatic hydrocarbon group, more preferably a linear, branched, cyclic 2-oxoalkyl group or alkoxycarbonylmethyl group, most preferably a linear, branched 2- An oxoalkyl group;

The aliphatic hydrocarbon group as R _{201 to} R ₂₀₃ may be a linear or branched alkyl group or a cycloalkyl group, and preferably a linear or branched alkyl group having 1 to 10 carbon atoms ( Examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group) and a cycloalkyl group having 3 to 10 carbon atoms (a cyclopentyl group, a cyclohexyl group, and a norbornyl group). As the aliphatic hydrocarbon group, a 2-oxoalkyl group and an alkoxycarbonylmethyl group are more preferable.

  The 2-oxoalkyl group may be linear, branched or cyclic, and preferably includes a group having> C = O at the 2-position of the above alkyl group or cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included.
Zc ⁻ represents a non-nucleophilic anion and is the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a straight chain having 1 to 12 carbon atoms. Examples thereof include a chain or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, a linear or branched pentyl group).

Examples of the cycloalkyl group as R _{1c to} R _7c include a cycloalkyl group having 3 to 20 carbon atoms, preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group). .

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any one of R _{1c to} R _5c is a straight chain, branched alkyl group, cycloalkyl group, or a straight chain, branched, or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same as the alkyl group and cycloalkyl group as R _{1c to} R _7c , and a 2-oxoalkyl group and an alkoxycarbonylmethyl group are more preferable. preferable.

Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .

  Rx and Ry are preferably an alkyl group or cycloalkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more alkyl groups or cycloalkyl groups.

Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

In formula (ZII), (ZIII), R 204 ~R 207 each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.

The alkyl group represented by R _{204 to} R ₂₀₇ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Butyl group, pentyl group).

Cycloalkyl groups R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).

Aryl group R ₂₀₄ to R _207, an alkyl group, a cycloalkyl group may have a substituent, an aryl group of R ₂₀₄ to R _207, an alkyl group, substituent that the cycloalkyl group have As, for example, an alkyl group (for example, carbon number 1-15), a cycloalkyl group (for example, carbon number 3-15), an aryl group (for example, carbon number 6-15), an alkoxy group (for example, carbon number 1-15), A halogen atom, a hydroxyl group, a phenylthio group, etc. can be mentioned.

X ⁻ represents a non-nucleophilic anion and is the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

  Moreover, what is represented by the following general formula (ZIV)-(ZVII) as another compound which generate | occur | produces an acid by irradiation of the actinic ray or radiation used for this invention is mentioned.

In general formulas (ZIV) to (ZVII),
Ar ³ and Ar ⁴ each independently represents an aryl group.
R ₂₀₆ represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.
R represents an alkyl group, a cycloalkyl group, or an aryl group.
_R207 represents an electron-withdrawing group, and preferably represents a cyano group or a fluoroalkyl group.
R ₂₀₈ represents an alkyl group, a cycloalkyl group, or an aryl group.

  Of the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable.

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, a sulfonium salt represented by the general formula (ZI) is more preferable, a sulfonium salt having a carbonyl group is particularly preferable, and a compound (ZI) is most preferable. -2), a compound having a 2-oxoalkyl group in any one of R _{201 to} R ₂₀₃ or a compound represented by the general formula (ZI-3). The sensitivity is particularly improved by using a compound having a carbonyl group.

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

  The content of the compound that generates an acid upon irradiation with actinic rays or radiation is preferably 6 to 20% by mass in the solid content of the positive resist composition.

[4] Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine atom and It is preferable that one or two or more surfactants containing both silicon atoms are contained.

  When the positive resist composition of the present invention contains the above-described surfactant, a resist pattern with good adhesion and low development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes possible.

  As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 405720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.

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

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

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

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

  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 amount of the positive resist composition (excluding the solvent).

[5] (D) Organic Basic Compound The positive resist composition of the present invention preferably contains an organic basic compound in order to reduce the change in performance over time from exposure to heating.

  Preferable structures include structures represented by the following formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, And R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. The alkyl group, cycloalkyl group and aryl group may be unsubstituted or have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and a 3 to 20 carbon atom. A hydroxycycloalkyl group is preferred.

  These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 20 carbon atoms.

  Preferred compounds include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted pyrazole, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, substituted or An unsubstituted aminoalkylmorpholine, a substituted or unsubstituted piperidine can be mentioned, and more preferable compounds are imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine. Examples thereof include a compound having a structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

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

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

[6] Organic solvent The positive resist composition of the present invention is used by dissolving each component in a predetermined organic solvent.

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

  In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent in which a solvent containing a hydroxyl group in the structure and a solvent not containing a hydroxyl group are mixed. . Thereby, the generation of particles during storage of the resist solution can be reduced.

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

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

  The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.

In the manufacture of precision integrated circuit elements, the pattern forming process on the resist film is carried out by applying the positive resist composition of the present invention on a substrate (eg, a transparent substrate such as a silicon / silicon dioxide covering, a glass substrate, an ITO substrate). A good resist pattern can be formed by applying an object, then irradiating with an actinic ray or radiation drawing apparatus, heating, developing, rinsing and drying.

  The film thickness of the resist film formed by applying and drying the positive resist composition of the present invention on a substrate is preferably 50 to 200 nm. By setting the thickness of the resist film to 50 to 200 nm, it is possible to improve the dry etching resistance and the pattern profile and increase the transmittance of the resist film.

  The film thickness of the resist film can be adjusted by the solid content concentration excluding the solvent of the composition, the preferable solid content concentration is 5 to 18% by mass, the more preferable solid content concentration is 7 to 15% by mass, and the particularly preferable solid content is The partial concentration is 9-14% by mass.

  Examples of the alkaline developer of the positive resist composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, and n-propylamine. Primary amines, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, An aqueous solution of an alkali such as a quaternary ammonium salt such as tetraethylammonium hydroxide or choline, or a cyclic amine such as pyrrole or piperidine can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.

  Among these alkaline developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and an aqueous solution of choline are more preferable.

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.

1. Constituent material (i) Cyclic compound (A)
About the cyclic compound (A) used in the Example of this invention, the commercial item was used as it was, or it synthesize | combined by the well-known synthesis method.
(Ii) Synthesis of Resin Synthesis Example 1 (Synthesis of Resin (P-1))
After dissolving 20 g of poly-p-hydroxystyrene in 80 g of PGMEA and heating to 60 ° C., the system was gradually depressurized to 20 mmHg, and PGMEA and water in the system were azeotropically dehydrated. After azeotropic dehydration, the mixture was cooled to 20 ° C., 6.50 g of benzyl vinyl ether was added, 3 mg of p-toluenesulfonic acid was further added, and the mixture was stirred for 2 hours.
After neutralizing the reaction solution with triethylamine, ethyl acetate was added to the reaction solution, and the salt was removed by washing with ion-exchanged water. Further, ethyl acetate and water were distilled off from the reaction solution under reduced pressure to obtain a PGMEA solution of the target resin (P-1).
(Iii) Synthesis of acid generator The acid generators used in the examples of the present invention were all synthesized by a known synthesis method.

Example 1
(I) Preparation and coating of positive resist Cyclic compound (CA-1) 0.40 g
Resin (P-1) 0.52g
Acid generator (z4) 0.08g
Was dissolved in 7.5 g of propylene glycol monomethyl ether acetate and 1.0 g of propylene carbonate, and 0.001 g of E-1 (see below) was further added as an organic basic compound to 7.0 g of propylene glycol monomethyl ether acetate, propylene glycol. Add and dissolve in 1.5 g of monomethyl ether, and further add and dissolve 0.001 g of Megafac F-176 (Dainippon Ink Chemical Co., Ltd., hereinafter referred to as “W-1”) as a surfactant. The resulting solution was microfiltered with a membrane filter having a 0.1 μm aperture to obtain a resist solution.
This resist solution was applied onto a 6-inch silicon wafer using a Tokyo Electron spin coater Mark 8 and baked at 110 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.30 μm.

(Ii) Production and Evaluation of Positive Resist Pattern This resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds, and dried. The obtained pattern was evaluated by the following method.
〔sensitivity〕
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). Sensitivity was defined as the minimum irradiation energy when resolving a 0.15 μm line (line: space = 1: 1).
[Resolution]
The resolving power was defined as the limiting resolving power (line and space were separated and resolving) at the irradiation dose showing the above sensitivity.
[Pattern shape]
Using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.), observe the cross-sectional shape of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and perform a three-step evaluation of rectangular, slightly tapered, and tapered. It was.
[Line edge roughness]
The line width was measured at any 30 points in the length direction of 50 μm of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and the variation was evaluated by 3σ.

(Iii) Evaluation Results The results of Example 1 were very good with a sensitivity of 4.9 μC / cm ² , a resolving power of 0.11 μm, a pattern shape of a rectangle, and line edge roughness of 6.5 nm.

Examples 2 to 10 and Comparative Example 1
Using the compounds shown in Table 1 below, resist preparation / coating and electron beam exposure evaluation were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

Other compounds used in Examples and Comparative Examples are shown below.
[Organic basic compounds]
E-1: Tri-n-hexylamine E-2: 2,4,6-triphenylimidazole E-3: Tetra- (n-butyl) ammonium hydroxide [Surfactant]
W-1: Fluorosurfactant, MegaFuck F-176 (Dainippon Ink Chemical Co., Ltd.)
W-2: Fluorine / silicone surfactant, MegaFac R08 (Dainippon Ink and Chemicals)
W-3: Silicone surfactant, polysiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  From Table 1, the positive resist composition of the present invention has a higher sensitivity and higher resolution with respect to pattern formation by electron beam irradiation than the composition of the comparative example, and is excellent in pattern shape and line edge roughness. I understand that.

<Evaluation by EUV exposure>
Examples 11-12 and Comparative Example 2
Using the resist compositions of Examples 1 and 2 and Comparative Example 1, resist films were obtained in the same manner as in Example 1. However, the resist film thickness was 0.15 μm. EU was added to the resulting resist film.
Using V light (wavelength 13 nm), surface exposure was performed while changing the exposure amount by 0.5 mJ in the range of 0 to 5.0 mJ, followed by baking at 110 ° C. for 90 seconds. Thereafter, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast.
The results are shown in Table 2.

  From Table 2, it can be seen that the positive resist composition of the present invention is superior in sensitivity and high contrast as compared with the composition of the comparative example in the property evaluation by irradiation with EUV light.

Claims (6)

(A) a cyclic compound having four or more phenol structures,
(B) A resin having a repeating unit represented by the following general formula (B1) and / or (B2), which has increased solubility in an alkali developer by the action of an acid, and (C) irradiation with actinic rays or radiation. A positive resist composition for electron beam, EUV or X-ray, comprising a compound capable of generating an acid.
In general formulas (B1) and (B2),
Z represents a hydroxyl group, a halogen atom, a cyano group, a nitro group, an acyl group, or an acyloxy group. When there are a plurality of Zs, the plurality of Zs may be the same or different.
A ₁ represents a group containing a cyclic carbon structure and decomposing by the action of an acid. A ₁ is, when a plurality, the plurality is A ₁ may be the same or different.
Ra represents a hydrogen atom, a methyl group, a halogen atom, a cyano group or a CF ₃ group.
Re represents a group that is decomposed by the action of an acid.
m represents an integer of 1 to 3.
n represents an integer of 0 to 2. 2. The positive resist composition for electron beam, EUV or X-ray according to claim 1, wherein the cyclic compound of component (A) is a compound having a repeating unit represented by the following general formula (C1): .
In general formula (C1),
G represents a divalent linking group.
p represents an integer of 1 to 3.
q represents an integer of 4 to 10. The electron beam, EUV, or group represented by A ₁ or 2 has a structure represented by the following general formula (X1) or (X2): A positive resist composition for X-rays.
In general formula (X1),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.
r represents an integer of 0 to 20.
In general formula (X2),
R ₁ and R ₂ each independently represents a hydrogen atom or an alkyl group.
W represents a divalent linking group.
Y represents a group selected from —O—, —OCO—, —COO—, —O—CH ₂ —, —NHCO—, —CONH—, —S—, —SO ₂ — and —SO ₃ —.
Za represents a cycloalkyl group or an aryl group. The cycloalkyl group may have a bridged structure.   (C) The compound which generate | occur | produces an acid by irradiation of actinic light or a radiation is contained in the range of 6-20 mass% in the total solid of this resist composition, The any one of Claims 1-3 characterized by the above-mentioned. A positive resist composition for electron beam, EUV or X-ray described in 1.   The positive resist composition for electron beam, EUV or X-ray according to any one of claims 1 to 4, further comprising (D) an organic basic compound.   A process comprising: forming a resist film from the positive resist composition according to any one of claims 1 to 5; and exposing and heating the resist film with an electron beam, EUV, or X-ray, and then developing the resist film. Pattern forming method.