JP2008241869A - Resist composition and method for forming pattern using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which reduces line edge roughness and development defects, gives a preferable profile and has excellent resolution of a hole pattern and side lobe margin, in techniques for improving performances in microprocessing of semiconductor elements using actinic rays or radiation, particularly, electron beams, X-rays, KrF excimer laser beams or ArF excimer laser beams, and to provide a method for forming a pattern using the above composition. <P>SOLUTION: The resist composition contains a nitrogen-containing compound having at least two bonds selected from ester bonds, amide bonds, urethane bonds and ureido bonds. The method for forming a pattern using the resist composition is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resist composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photo-publishing processes, and a pattern forming method using the resist composition. More specifically, the present invention relates to a resist composition capable of forming a highly refined pattern using an electron beam, X-ray, excimer laser, or the like, and a pattern forming method using the resist composition.

Conventionally, in chemically amplified resists consisting of resins that increase the solubility in an alkaline developer due to the action of acid, or compounds that generate acid upon irradiation with actinic rays or radiation, organic amine compounds are added from the viewpoint of improving resolution. It has been broken. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2000-181655) discloses a combination of an acid-generating compound and an amine compound having a boiling point of 250 ° C. or lower, and Patent Document 2 (Japanese Patent Publication No. 7-508840) discloses an amide compound. Each of these combinations is disclosed. Further, a maleimide compound is disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 3-200968), and a sulfonamide compound is disclosed in Patent Document 4 (Japanese Patent Laid-Open No. 7-92680).
Further, nitrogen-containing compounds are studied as a substrate dependence improving agent in Patent Document 5 (Japanese Patent Laid-Open No. 11-44950) and as an acid deactivator in Patent Document 6 (Japanese Patent Laid-Open No. 7-225481).
None of these attempts to improve the resist pattern profile, line edge roughness, and number of development defects.

JP 2000-181065 A Japanese National Patent Publication No. 7-508840 Japanese Patent Laid-Open No. 3-200968 Japanese Patent Laid-Open No. 7-92680 JP 11-44950 A JP-A-7-225481

  The object of the present invention is to solve the problem of the technology for improving performance in microfabrication of semiconductor devices using actinic rays or radiation, particularly electron beams, X-rays, KrF excimer laser light, ArF excimer laser light, An object of the present invention is to provide a resist composition that has reduced roughness and development defects, has a good profile, has excellent resolution in a hole pattern, and has excellent sidelobe margin, and a pattern forming method using the same.

  The present invention is achieved by the following configurations.

(1) A resist composition comprising a nitrogen-containing compound having at least two bonds selected from ester bonds, amide bonds, urethane bonds, and ureido bonds.
(2) The resist composition as described in (1) above, wherein the nitrogen-containing compound is a tertiary amine.
(3) The resist composition as described in (1) or (2) above, wherein the nitrogen-containing compound has a molecular weight of 290 to 1,000.
(4) The resin according to any one of (1) to (3) above, further comprising a resin whose solubility in an alkali developer is increased by the action of an acid and a compound capable of generating an acid upon irradiation with actinic rays or radiation. The positive resist composition according to any one of the above.
(5) The resin whose solubility in an alkaline developer is increased by the action of the acid is a resin containing at least one repeating unit represented by the following general formula (A1) or (A2) The positive resist composition as described in (4) above.

In general formula (A1),
A ₁ is represented by —C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), —C (R ⁰⁴ ) (R ⁰⁵ ) —O—R ⁰⁶ , or —CH (R ⁰⁶ ) (R ⁰⁷ ). It represents a group capable of leaving by the action of an acid.
R ^{01 to} R ⁰³ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. These groups may be bonded to each other to form a ring. R ⁰⁴ and R ⁰⁵ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁶ represents an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁷ represents an aryl group.
S ₁ represents a substituent, and when there are a plurality of them, they may be the same or different.
n shows the integer of 0-3. m shows the integer of 0-3. However, m + n ≦ 5.

In general formula (A2),
A ₂ represents a group capable of leaving by the action of an acid represented by —C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ).
R ^{01 to} R ⁰³ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. These groups may be bonded to each other to form a ring.
X represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkyloxycarbonyl group.

(6) The compound that generates an acid upon irradiation with actinic rays or radiation is at least one selected from triarylsulfonium salts of organic sulfonic acids, and at least one selected from diazodisulfones and oxime esters of organic sulfonic acids. The positive resist composition as described in (4) or (5) above, comprising:

(7) The compound that generates an acid upon irradiation with active light or radiation is at least one selected from compounds that generate an organic sulfonic acid upon irradiation with active light or radiation, and a carboxylic acid upon irradiation with active light or radiation. Or the positive resist composition as described in said (4) or (5) characterized by including at least 1 sort (s) chosen from the compound which generate | occur | produces an imide acid.

(8) A pattern forming method comprising a step of forming a resist film from the resist composition according to any one of (1) to (7), and exposing and developing the resist film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a resist composition in which line edge roughness and development defects are reduced, the profile is good, the resolution in a hole pattern, and the side lobe margin is excellent, and a pattern formation method using the same. .

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

[1] (C) Nitrogen-containing compound The resist composition of the present invention comprises an amine compound having at least two bonds selected from an ester bond, an amide bond, a urethane bond and a ureido bond (hereinafter referred to as “component (C)”. (Also called).
It may have two or more identical bonds such as two ester bonds, or may have two or more different bonds such as an ester bond and an amide bond.
Among them, the component (C) having a hydrogen-bonding amide bond, urethane bond or ureido bond is heated after exposure (PEB) due to the interaction with (B) a resin whose solubility in an alkali developer is increased by the action of an acid. Diffusion and volatilization of the component (C) in the resist film in the process are suppressed.

  As the component (C) of the present invention, primary, secondary, and tertiary amine compounds can be used. That is, the amine compound of the present invention may have at least one organic group on the nitrogen atom. Examples of the organic group include an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (including bridged polycycles, preferably 3 to 20 carbon atoms), and an aryl group (preferably having 6 to 6 carbon atoms). 12). Of these, tertiary amine compounds are preferred.

(C) The ester bond, amide bond, urethane bond and ureido bond of the component are present in the organic group bonded to the nitrogen atom, that is, the nitrogen atom and the ester bond, amide bond, urethane bond and ureido bond are It is preferable not to be directly connected.
Organic groups containing an ester bond, an amide bond, a urethane bond, or a ureido bond may have a hetero atom in addition to these bonds, and also an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group A substituent such as a group, a carboxylic acid ester group, a sulfonic acid ester group, an acyloxy group or an aryloxy group. Among ester bonds, amide bonds, urethane bonds, and ureido bonds, amide bonds, urethane bonds, and ureido bonds having strong hydrogen bonding properties are preferable.

  The component (C) preferably has 2 to 12 bonds selected from ester bonds, amide bonds, urethane bonds and ureido bonds, and more preferably 3 to 6 bonds.

  The component (C) of the present invention preferably has a molecular weight of 290 to 1,000. More preferably, it is 350-800, More preferably, it is 400-600. In terms of suppressing diffusion and volatilization of the component (C) in the resist film in the post-exposure heating (PEB) step, the molecular weight is preferably large, and the alkali development characteristics and scum of the resin whose solubility in an alkaline developer is increased by the action of an acid. From the viewpoint of reducing development defects, a smaller molecular weight is preferable.

  Specific examples of the nitrogen-containing compound (C) are shown below, but the present invention is not limited thereto.

As the compound (C) of the present invention, a commercially available product or a compound synthesized by a known method may be used. The compound (C) of the present invention includes, for example, a reaction between a tertiary amine compound having two or more hydroxyl groups and an organic isocyanate compound or an organic carboxylic acid, a tertiary amine compound having two or more NH ₂ groups, and an organic compound. It can be obtained by reacting with an isocyanate compound or an organic carboxylic acid.

  The usage-amount of a nitrogen-containing compound (C) is 0.001-10 mass% normally on the basis of solid content of a resist composition, Preferably it is 0.01-5 mass%.

[2] (A) Compound capable of generating an acid upon irradiation with actinic rays or radiation A compound capable of generating an acid upon irradiation with actinic rays or radiation contained in the positive resist composition of the present invention (hereinafter referred to as "acid generator" or (Also referred to as “component (A)”)
The photosensitive composition of this invention contains the compound which generate | occur | produces an acid by irradiation of actinic light or a radiation. Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

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

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

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

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

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF4-, PF6-, SbF6-, etc. An organic anion containing a carbon atom is preferred.
Preferable organic anions include organic anions represented by the following formulas AN1 to AN4.

Rc1 represents an organic group.
Rd1 represents a hydrogen atom or an alkyl group.
As the organic group for Rc1, an alkyl group having 1 to 30 carbon atoms, preferably an alkyl group which may be substituted, an aryl group, or a plurality of these are a single bond, —O—, —CO 2 —, —S—, And groups linked by a linking group such as —SO 3 — and —SO 2 N (Rd 1) —.
Rd1 represents a hydrogen atom or an alkyl group, and may form a ring structure with the bonded alkyl group or aryl group.
The organic group of Rc1 is more preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. When Rc1 has 5 or more carbon atoms, at least one carbon atom is preferably substituted with a hydrogen atom, and more preferably, the number of hydrogen atoms is larger than that of fluorine atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.

The most preferred embodiment of Rc1 is a group represented by Rc7-Ax-Rc6-.
Rc6 is a phenylene group substituted with a perfluoroalkylene group having 4 or less carbon atoms, more preferably 2 to 4 carbon atoms, still more preferably 2 to 3 carbon atoms, 1 to 4 fluorine atoms and / or 1 to 3 fluoroalkyl groups. .
Ax is a linking group (preferably a single bond, —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd1) —). Rd1 represents a hydrogen atom or an alkyl group, and may combine with Rc7 to form a ring structure.
Rc7 represents a hydrogen atom, a fluorine atom, an optionally substituted linear, branched, monocyclic or polycyclic alkyl group, or an optionally substituted aryl group. It is preferable that the alkyl group and aryl group which may be substituted do not contain a fluorine atom as a substituent.
Rc3, Rc4 and Rc5 represent an organic group.
Preferred examples of the organic group for Rc3, Rc4, and Rc5 include the same organic groups as those for Rc1.
Rc3 and Rc4 may be bonded to form a ring.
Examples of the group formed by combining Rc3 and Rc4 include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group. By combining Rc3 and Rc4 to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved, which is preferable.

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

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

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

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
Arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group or a part of R ₂₀₁ to R ₂₀₃ may be an aryl group with the remaining being an alkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, and an aryldialkylsulfonium compound.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec. -Butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group and the like can be mentioned.
Aryl group R ₂₀₁ to R _203, an alkyl group, an alkyl group (for example, 1 to 15 carbon atoms), an aryl group (e.g., carbon number 6 to 14), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, You may have a hydroxyl group and a phenylthio group as a substituent. Preferred substituents are linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, most preferably alkyl groups having 1 to 4 carbon atoms, It is a C1-C4 alkoxy group. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

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

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, branched, or cyclic, preferably a linear or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group) and cyclic alkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably includes a group having> C═O at the 2-position of the above alkyl group. it can.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferred examples include an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, butyl group, pentyl group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
Two members out of R _{201 to} R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

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

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c represent a hydrogen atom or an alkyl group.
Rx and Ry each independently represents an alkyl group, a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an allyl group, or a vinyl group.
Any two or more of R _{1c to} R _5c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom, a sulfur atom, an ester bond, and an amide bond. May be included.

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

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _5c .
Examples of the 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group as R _{1c to} R _5c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

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

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

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

In general formulas (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₆ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
_R207 and _{R208 each represents a} substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or an electron-withdrawing group. R ₂₀₇ is preferably a substituted or unsubstituted aryl group.
R ₂₀₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

Of the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, more preferred are compounds represented by general formulas (ZI) to (ZIII), and even more preferred are compounds represented by (ZI). Most preferred are compounds represented by (ZI-1) to (ZI-3).
Furthermore, the compound which generate | occur | produces the acid represented by the following general formula AC1-AC3 by irradiation of actinic light or a radiation is preferable.

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

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

As the acid generator, a commercially available one may be used, or one synthesized by a known method may be used.
An acid generator can be used individually by 1 type or in combination of 2 or more types.
A combination of a triarylsulfonium salt of an organic sulfonic acid and diazodisulfone or an oxime ester of an organic sulfonic acid is preferable because the number of development defects is further reduced.
The ratio (mass ratio) of the total amount of triarylsulfonium salt of organic sulfonic acid and diazodisulfone or oxime ester of organic sulfonic acid is preferably 20/80 to 80/20, more preferably 30/70 to 70/30. .
A combination of a compound that generates an organic sulfonic acid upon irradiation with actinic rays or radiation and a compound that generates a carboxylic acid or imide acid upon irradiation with actinic rays or radiation is preferable because the line edge roughness is further reduced.
The ratio (mass ratio) of the total amount of the compound that generates an organic sulfonic acid upon irradiation with actinic rays or radiation and the compound that generates carboxylic acid or imide acid upon irradiation with actinic rays or radiation is preferably 90/10 to 30/70. More preferably, it is 80 / 20-50 / 50.
When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the acid generator in the composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably 1 to 7% by mass, based on the total solid content of the resist composition. %.

[3] (B) Resin whose solubility in an alkali developer is increased by the action of an acid A compound (hereinafter referred to as “(B)” whose solubility in an alkali developer is increased by the action of an acid used in the positive resist composition of the present invention. As the “component”), a resin having a group capable of decomposing with an acid in the main chain or side chain of the resin or in both the main chain and the side chain is preferable. Among these, a resin having a group capable of decomposing with an acid in the side chain is more preferable.
Preferred groups as the group capable of decomposing with an acid are —COOA ⁰ and —O—B ⁰ groups, and further groups containing these are represented by —R ⁰ —COOA ⁰ or —A _r —O—B ⁰ . Group.
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.
Ar is an arylene group (preferably having 6 to 12 carbon atoms), and a phenylene group is particularly preferable.
R ⁰ is a single bond or an alkylene group (preferably having 1 to 6 carbon atoms), preferably a single bond or an alkylene group having 1 to 4 carbon atoms, and particularly preferably a single bond or 1 or 2 carbon atoms. An alkylene group.

R ^{01 to} R ⁰³ are each independently an alkyl group (preferably having 1 to 8 carbon atoms), a cycloalkyl group (preferably having 4 to 10 carbon atoms), an aryl group (preferably having 6 to 15 carbon atoms), These groups may combine with each other to form a ring (including a bridged ring).
R ^{01 to} R ⁰³ are preferably each independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or an aryl group having 6 to 12 carbon atoms, particularly preferably each independently. And an alkyl group having 1 to 4 carbon atoms, a cyclohexyl group, and a phenyl group.
R ⁰⁴ and R ⁰⁵ are each independently a hydrogen atom or an alkyl group (preferably having 1 to 8 carbon atoms), preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, particularly preferably a hydrogen atom or a carbon atom. It is a C 1-4 alkyl group.
R ⁰⁶ is an alkyl group (preferably having 1 to 15 carbon atoms) which may contain an ether group or thioether group, a cycloalkyl group (preferably having 4 to 10 carbon atoms), an aryl group (preferably having 6 to 15 carbon atoms). ) Or a combination of these groups. R ⁰⁶ is preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, or these groups, which may contain an ether group or a thioether group. In particular, an alkyl group having 1 to 8 carbon atoms which may contain an ether group or a thioether group, a cyclohexyl group, a phenyl group, a naphthyl group, or a group obtained by combining these groups.
Further, R ⁰⁶ preferably forms a ring together with R ⁰⁴ or R ⁰⁵ .

  The acid-decomposable group is preferably a silyl ether group, cumyl ester group, acetal group, tetrahydropyranyl ether group, enol ether group, enol ester group, tertiary alkyl ether group, tertiary alkyl ester group, Tertiary alkyl carbonate groups and the like. More preferred are a tertiary alkyl ester group, a tertiary alkyl carbonate group, a cumyl ester group, an acetal group, and a tetrahydropyranyl ether group.

Next, as a base resin in the case where these acid-decomposable groups are bonded as side chains, alkali-soluble resins having —OH or —COOH, preferably —R ⁰ —COOH or —A _r —OH groups in the side chains. Resin. For example, the alkali-soluble resin mentioned later can be mentioned.

The alkali dissolution rate of these alkali-soluble resins is preferably at least 170 kg / sec as measured with 0.261 N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferred is 330 liters / second or more.
From this point of view, particularly preferred alkali-soluble resins are o-, m-, p-poly (hydroxystyrene) and copolymers thereof, hydrogenated poly (hydroxystyrene), halogen or alkyl-substituted poly (hydroxystyrene). , Part of poly (hydroxystyrene), O-alkylated or O-acylated product, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, and hydrogenated novolac resin.

  Component (B) used in the present invention is 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 is possible to obtain an alkali-soluble resin monomer having a group capable of being decomposed or reacting with an acid-decomposable group by copolymerization with various monomers.

  The component (B) is preferably a resin having a repeating unit represented by the following general formula (A1) or (A2).

In general formula (A1),
A ₁ is represented by —C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), —C (R ⁰⁴ ) (R ⁰⁵ ) —O—R ⁰⁶ , or —CH (R ⁰⁶ ) (R ⁰⁷ ). It represents a group capable of leaving by the action of an acid, and when there are a plurality of groups, they may be the same or different.
In the formula, R ^{01 to} R ⁰³ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. These groups may be bonded to each other to form a ring (including a bridged ring). R ⁰⁴ and R ⁰⁵ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁶ represents an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁷ represents an aryl group.
S ₁ represents a substituent, and when a plurality of S ₁ are present, they may be the same or different.
n shows the integer of 0-3. m shows the integer of 0-3. However, m + n ≦ 5.

In general formula (A1), the alkyl group represented by R ^{01 to} R ⁰⁶ is preferably an alkyl group having 1 to 8 carbon atoms.
The cycloalkyl group of R ^{01 to} R ⁰⁶ is preferably a cycloalkyl group having 4 to 10 carbon atoms.
The aryl group of R ^{01 to} R ⁰⁶ is preferably an aryl group having 6 to 15 carbon atoms.
The alkyl group of X may have a substituent. Examples of the alkyl group having a substituent include a CF ₃ group, an alkyloxycarbonylmethyl group, an alkylcarbonyloxymethyl group, a hydroxymethyl group, and an alkoxymethyl group.
Examples of the substituent for S ₁ include an alkyl group, an alkoxy group, a halogen atom, a cyano group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, and an aralkyl group.
Hereinafter, although the specific example of the monomer corresponding to the repeating unit shown by general formula (A1) is shown, this invention is not limited to this.

In general formula (A2), the alkyl group as X is preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group. The alkyl group as X may be substituted with a fluorine atom or the like. The substituted alkyl group, (represents the C _m F _{2m + 1} group, m is an integer from 1 to 4) perfluoro group can be exemplified.
X is preferably a hydrogen atom, a methyl group, or a C _m F _{2m + 1} group (m is preferably 1), and particularly preferably a hydrogen atom or a methyl group.

In general formula (A2), the group capable of leaving by the action of an acid as A ₂ is eliminated by the action of an acid generated by exposure to generate a carboxylic acid derived from an ester group in the structure of general formula (A2). It is a group to be made.
R ⁰¹ to R ⁰³ in the group represented by -C as ^{_{A 2 (R 01) (R}} 02) (R 03) , as well as the R ⁰¹ to R ⁰³ in the group of A ₂ in the general formula (A1) Each independently represents an alkyl group, a cycloalkyl group or an aryl group, and these groups may be bonded to each other to form a ring (including a bridged ring).
The group capable of leaving by the action of an acid as A ₂ preferably has an alicyclic group, and the alicyclic group may be a bridged alicyclic group.

The group capable of leaving by the action of an acid as A ₂ is preferably a group represented by the following general formula (pI) to general formula (pVI).

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.
Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom.
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.
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. However, 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 hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ may be substituted or unsubstituted, and is a linear or branched alkyl group having 1 to 4 carbon atoms. Represents. 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.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

The alicyclic hydrocarbon group in R _{12 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. 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 alicyclic hydrocarbon groups may have a substituent.

  Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

  In the present invention, preferred examples of the alicyclic moiety include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, 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, and a cyclododecanyl 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 the alkoxy group may have a further substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.
Hereinafter, although the specific example of the monomer corresponding to the repeating unit shown by general formula (A2) is shown, this invention is not limited to this.

  Although the specific example of (B) component used for this invention is shown below, it is not limited to these.

  In the above specific example, tBu represents a t-butyl group.

The weight average molecular weight (Mw) of the component (B) is preferably in the range of 2,000 to 200,000. More preferably, it is the range of 5,000-100,000, More preferably, it is the range of 8,000-50,000.
Moreover, molecular weight distribution (Mw / Mn) becomes like this. Preferably it is 1.0-4.0, More preferably, it is 1.0-2.0, Most preferably, it is 1.0-1.6.
Here, the weight average molecular weight is defined by a polystyrene conversion value of gel permeation chromatography.

The resin of component (B) can be synthesized by a known polymerization method such as a radical polymerization method.
(B) You may use a component in combination of 2 or more types.

  The amount of component (B) added is suitably from 80 to 98 mass%, preferably from 85 to 96 mass%, based on the solid content of the positive resist composition.

[4] (D) Alkali-soluble compound The alkali-soluble compound is preferably an alkali-soluble resin.
The alkali-soluble resin preferably has an alkali dissolution rate of 20 liters / second or more as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 200 Å / second or more.
In addition, the resist composition of the present invention can be used for a negative resist by using (D) an alkali-soluble compound and a crosslinking agent instead of a resin whose solubility in an alkaline developer is increased by the action of an acid. I can do it.

  Examples of the alkali-soluble resin include novolak resin, hydrogenated novolak resin, acetone-pyrogalol resin, o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene, hydrogenated polyhydroxystyrene, halogen or alkyl-substituted polyhydroxy. Styrene, hydroxystyrene-N-substituted maleimide copolymer, o / p- and m / p-hydroxystyrene copolymer, partially O-alkylated product of hydroxyl group of polyhydroxystyrene (for example, 5-30 mol% O -Methylated product, O- (1-methoxy) ethylated product, O- (1-ethoxy) ethylated product, O-2-tetrahydropyranylated product, O- (t-butoxycarbonyl) methylated product, etc.) or O-acylated product (E.g. 5-30 mol% o-acetylation , O- (t-butoxy) carbonylated compounds, etc.), styrene-maleic anhydride copolymer, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, carboxyl group-containing methacrylic resin and derivatives thereof Polyvinyl alcohol derivatives can be mentioned, but are not limited thereto.

  Particularly preferred alkali-soluble resins are novolak resins and o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene and copolymers thereof, alkyl-substituted polyhydroxystyrenes, partially O-alkylated polyhydroxystyrenes, Alternatively, O-acylated product, styrene-hydroxystyrene copolymer, and α-methylstyrene-hydroxystyrene copolymer.

  The novolak resin is obtained by subjecting a predetermined monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst.

  The weight average molecular weight of the alkali-soluble resin is 2000 or more, preferably 5,000 to 200,000, more preferably 5,000 to 100,000.

  Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.

  Two or more alkali-soluble resins may be used in combination.

  The usage-amount of an alkali-soluble compound is 40-97 mass% with respect to solid content of the whole composition of a resist composition, Preferably it is 60-90 mass%.

[5] Other components The resist composition of the present invention may further contain a radical generator, a nitrogen-containing basic compound, a dye, a surfactant and the like, if necessary.

<Nitrogen-containing basic compound>
The resist composition of the present invention can further contain a nitrogen-containing basic compound in addition to the nitrogen-containing compound (C).
The nitrogen-containing basic compound used in the present invention is preferably a nitrogen-containing basic compound having a stronger basicity than phenol.
As a preferable chemical environment, structures of the following formulas (A) to (E) can be exemplified.

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group. (Preferably having 6 to 20 carbon atoms). The alkyl group, cycloalkyl group, and aryl group may be substituted with an amino group, a hydroxyl group, or the like. R ²⁵¹ and R ²⁵² may combine with each other to form a ring.
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms.
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

  Preferred examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, imidazole, substituted or unsubstituted Substituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted Aminomorpholine, substituted or unsubstituted aminoalkylmorpholine, and the like. Preferred substituents are amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group It is.

  Particularly preferred compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4 , 5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4- Aminoethylpyridine,

  3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl)- Examples include 5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine. It is not limited to this.

  The nitrogen-containing basic compound is used in combination with an amine compound having at least two bonds selected from the ester bond, amide bond, urethane bond and ureido bond of the present invention, based on the solid content of the resist composition. Usually, it is 0.001-10 mass%, 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.

<Dye>
Suitable dyes include oily dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (oriental chemical industry) Co., Ltd.), crystal violet (CI42555), methyl violet (CI42535), rhodamine B (CI45170B), malachite green (CI42000), methylene blue (CI522015) and the like.

<Solvents>
The composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. Solvents used here 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-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.

<Surfactants>
The resist composition of the present invention preferably contains a surfactant.
Specific examples of the surfactant that can be used include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, and polyoxyethylene octylphenol. Ether, polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate Sorbitan fatty acid esters such as sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polio Shi ethylene sorbitan mono palmitate - door,

  Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, F-top EF301, EF303, EF352 (Shin-Akita Kasei) (Made by Co., Ltd.), MegaFuck F171, F173 (Dainippon Ink Co., Ltd.), Florad FC430, FC431 (Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103 , SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), etc., Troysol S-366 (manufactured by Troy Chemical Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and acrylic Acid or methacrylic acid-based (co) polymer Polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.).

The compounding quantity of surfactant is 2 mass parts or less normally with respect to 100 mass parts of solid content in the composition of this invention, Preferably it is 1 mass part or less.
These surfactants may be added alone or in some combination.

  In the manufacture of precision integrated circuit elements, etc., the pattern formation process on the resist film is carried out by applying the resist composition of the present invention on a substrate (eg, a transparent substrate such as a silicon / silicon dioxide cover, a glass substrate, an ITO substrate). A good resist pattern can be formed by applying, then irradiating with actinic rays or radiation, heating, developing, rinsing and drying. Here, the active light or radiation is preferably an electron beam, X-ray, light having a wavelength of 150 to 250 nm (KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), etc.) and the like. Particularly preferable are an electron beam and a KrF excimer laser.

  In the present invention, a commercially available inorganic or organic antireflection film can be used if necessary. Further, an antireflection film can be applied to the upper layer of the resist.

As the antireflection film used as the lower layer of the resist, either an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, or an organic film type made of a light absorber and a polymer material may be used. it can. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone light absorber described in JP-A-8-87115, and a low molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.

  In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

Examples of the developer for 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, n-propylamine and the like. 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, tetraethyl Aqueous solutions of alkalis such as quaternary ammonium salts such as ammonium hydroxide and choline, cyclic amines such as pyrrole and piperidine, and the like can be used. In addition, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.
Among these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the content of this invention is not limited by this.

[Synthesis Example 1: Synthesis of Resin Example (R-7)]
32.4 g (0.2 mol) of p-acetoxystyrene, 7.01 g (0.07 mol) of tert-butyl acrylate, and styrene (0.04 mol) were dissolved in 120 ml of butyl acetate. At 80 ° C., 0.033 g of azobisisobutyronitrile (AIBN) was added three times every 2.5 hours, and finally the stirring was continued for another 5 hours to carry out the polymerization reaction. The reaction solution was added to 1200 ml of hexane to precipitate a white resin. The obtained resin was dried and then dissolved in 200 ml of methanol.
To this was added an aqueous solution of sodium hydroxide (7.7 g, 0.19 mol) / water (50 ml) and the mixture was hydrolyzed by heating under reflux for 1 hour. Thereafter, 200 ml of water was added for dilution, and neutralized with hydrochloric acid to precipitate a white resin. The resin was filtered off, washed with water and dried. Furthermore, it melt | dissolved in tetrahydrofuran 200 ml, and it dripped and reprecipitated, stirring vigorously in 5 L of ultrapure water. This reprecipitation operation was repeated three times. The obtained resin was dried in a vacuum dryer at 120 ° C. for 12 hours to obtain a poly (styrene / p-hydroxystyrene / t-butyl acrylate) copolymer.

  The molar ratio of repeating units (in order from the left in the structural formula), weight average molecular weight, and degree of dispersion in each resin used in the examples are shown below.

[Example 1]
(1) Preparation and coating of resist composition (component A): acid generator z2 0.05 g
(Component B): Resin (R-1) 0.94 g
Is dissolved in 8.5 g of propylene glycol monomethyl ether acetate, 0.01 g of (C1-1) is added as a C component, and Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc., hereinafter referred to as W) is added as a surfactant. 0.001 g) was added and dissolved, and the resulting solution was microfiltered with a 0.1 μm aperture membrane filter to obtain a resist composition.
This resist composition was applied onto a 6-inch silicon wafer provided with an organic antireflection film (Brewer Science Co., Ltd. (DUV-42)) using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds. As a result, a uniform film having a thickness of 0.30 μm was obtained.

(2) Preparation of resist pattern and its evaluation The resist film formed as described above was subjected to pattern exposure using a KrF excimer stepper (FPA3000EX-5 manufactured by Canon Inc., wavelength 248 nm), and then 110 ° C., 90 ° C. After baking for 2 seconds and immersing in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, the substrate was rinsed with water for 30 seconds and dried.
The obtained pattern was evaluated by the following method.

(2-1) Resist pattern shape The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope.
(2-2) Line Edge Roughness For a range of 5 μm long edge in 1: 1 line / space pattern (line width 170 nm), the distance from the reference line where the edge should be measured is SEM (Hitachi, Ltd.) 30 points were measured by S-8840), and the standard deviation was determined to calculate 3σ. Smaller values indicate better properties.

(2-2) Development Defects The number of defects was measured on the entire surface of an 8-inch wafer on which a line / space (1: 1) pattern was formed by KrF exposure using a development defect inspection apparatus manufactured by KLA Tencor.
The evaluation results are shown in Table 2.

[Examples 2 to 17 and Comparative Example 1]
A resist composition was prepared, coated, exposed, patterned, and evaluated in exactly the same manner as in Example 1 except that the compounds shown in Table 2 were used.
The evaluation results are shown in Table 2.

Other compounds used in Table 2 are shown below.
C2: Bis (hydroxyethyl) methylamine W-2: Polysiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

<Evaluation of KrF / sidelobe margin>
An anti-reflection film DUV-44 manufactured by Brewer Science Co., Ltd. was uniformly applied to a thickness of 85 nm on a silicon substrate subjected to hexamethyldisilazane treatment with a spin coater, and dried on a hot plate at 100 ° C. for 90 seconds. Heat drying was performed at 200 ° C. for 240 seconds.
Thereafter, the resist compositions of Examples 1 to 17 and Comparative Example 1 were applied by a spin coater and dried at 110 ° C. for 90 seconds to form a 0.40 μm resist film.
The resist film was exposed with a KrF excimer laser stepper using a halftone phase shift mask with a transmittance of 6%, and immediately after the exposure, it was heated on a hot plate at 115 ° C. for 90 seconds. Further, the resist film was developed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and then dried to obtain a contact hole pattern.
A mask pattern having a hole size of 180 nm and a duty ratio of 1: 2 is exposed, and the produced pattern is observed using a length measuring SEM S-9260 manufactured by Hitachi, Ltd., and an exposure amount that reproduces a 140 nm contact hole is an optimum exposure amount Eopt. The side lobe margin defined by the following equation was calculated with the exposure amount at which the side lobe is generated as Elimit. A larger value indicates higher sidelobe resistance.
Sidelobe margin (%) = [(Elimit-Eopt) / Eopt] × 100
The results are shown in Table 3.

  From Table 3, it is clear that the positive resist composition of the present invention is excellent in resolving power and side lobe margin as well as line edge roughness, pattern profile, and development defect number when exposed to KrF excimer laser light. .

<Synthesis Example 2 (Synthesis of Resin (R-21))>
Under a nitrogen stream, 8.6 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 9.8 g of 2-adamantyl isopropyl methacrylate, 4.4 g of dihydroxyadamantyl methacrylate, 8.9 g of norbornane lactone methacrylate, and 8 mol% of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries) were dissolved in 79 g of cyclohexanone. The solution was added dropwise over 6 hours. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise to a mixed solution of hexane 800 m / ethyl acetate 200 ml over 20 minutes, and the precipitated powder was collected by filtration and dried to obtain 19 g of Resin (R-21). The weight average molecular weight of the obtained resin was 8500 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 1.85.

  The molar ratio of repeating units in each resin used in the examples (in order from the left in the structural formula), the weight average molecular weight, and the degree of dispersion are shown.

Example 18
(3) Preparation and coating of resist composition (component A): acid generator z2 0.05 g
(Component B): Resin (R-21) 0.94 g
Is dissolved in 14.5 g of propylene glycol monomethyl ether acetate, 0.01 g of (C1-1) is added as a C component, and Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc., hereinafter W) is added as a surfactant. 0.001 g) was added and dissolved, and the resulting solution was microfiltered with a 0.1 μm aperture membrane filter to obtain a resist composition.
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. The prepared resist composition was applied thereon, and baked at 130 ° C. for 60 seconds to form a 250 nm resist film.

(4) Creation of resist pattern and its evaluation)
The resist film formed as described above was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, σo / σi = 0.85 / 0.55 manufactured by ASML). Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.

(4-1) Resist pattern shape The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope.
(4-2) Line Edge Roughness For the range of 5 μm in the longitudinal direction in the 1: 1 line / space pattern (line width 90 nm), the distance from the reference line where the edge should be is measured SEM (Hitachi, Ltd.) 30 points were measured by S-8840), and the standard deviation was determined to calculate 3σ. Smaller values indicate better properties.
(4-3) Development Defects The number of defects was measured with a development defect inspection apparatus manufactured by KLA Tencor on the entire surface of an 8-inch wafer on which a line / space (1: 1) pattern was formed by ArF exposure.

[Examples 19 to 34 and Comparative Example 2]
Except for using the compounds shown in Table 5, a resist composition was prepared, coated, exposed and patterned in the same manner as in Example 18 for evaluation.
The evaluation results are shown in Table 5.

Other compounds used in Table 5 are shown below.
C2: Bis (hydroxyethyl) methylamine W-2: Polysiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  From Table 5, it can be seen that the positive resist composition of the present invention suppresses the occurrence of line edge roughness and development defects upon exposure with ArF excimer laser light, and also has a good pattern profile.

Claims (8)

  A resist composition comprising a nitrogen-containing compound having at least two bonds selected from an ester bond, an amide bond, a urethane bond, and a ureido bond.   The resist composition according to claim 1, wherein the nitrogen-containing compound is a tertiary amine.   The resist composition according to claim 1 or 2, wherein the nitrogen-containing compound has a molecular weight of 290 to 1,000.   The positive electrode according to any one of claims 1 to 3, further comprising a resin whose solubility in an alkaline developer is increased by the action of an acid, and a compound which generates an acid upon irradiation with actinic rays or radiation. Type resist composition. 5. The resin whose solubility in an alkali developer is increased by the action of the acid, which is a resin containing at least one repeating unit represented by the following general formula (A1) or (A2). The positive resist composition as described in 1. above.

In general formula (A1),
A ₁ is represented by —C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), —C (R ⁰⁴ ) (R ⁰⁵ ) —O—R ⁰⁶ , or —CH (R ⁰⁶ ) (R ⁰⁷ ). It represents a group capable of leaving by the action of an acid.
R ^{01 to} R ⁰³ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. These groups may be bonded to each other to form a ring. R ⁰⁴ and R ⁰⁵ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁶ represents an alkyl group, a cycloalkyl group or an aryl group. R ⁰⁷ represents an aryl group.
S ₁ represents a substituent, and when there are a plurality of them, they may be the same or different.
n shows the integer of 0-3. m shows the integer of 0-3. However, m + n ≦ 5.
In general formula (A2),
A ₂ represents a group capable of leaving by the action of an acid represented by —C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ).
R ^{01 to} R ⁰³ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. These groups may be bonded to each other to form a ring.
X represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkyloxycarbonyl group.   The compound that generates an acid upon irradiation with actinic rays or radiation contains at least one selected from triarylsulfonium salts of organic sulfonic acids, and at least one selected from diazodisulfones and oxime esters of organic sulfonic acids. The positive resist composition according to claim 4 or 5, wherein:   The compound that generates acid upon irradiation with active light or radiation is at least one selected from compounds that generate organic sulfonic acid upon irradiation with active light or radiation, and carboxylic acid or imide acid upon irradiation with active light or radiation. The positive resist composition according to claim 4, wherein the positive resist composition contains at least one selected from the group consisting of compounds capable of generating.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1; and exposing and developing the resist film.