JP2005309408A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition having small PEB temperature dependency and good balance of sensitivity, exposure latitude, resolution and profile, and to provide a pattern forming method using the same. <P>SOLUTION: The positive resist composition contains a compound represented by formula (S) wherein Ar represents aryl; R<SB>1</SB>and R<SB>2</SB>each independently represents H, alkyl, cycloalkyl or aryl, R<SB>1</SB>and R<SB>2</SB>may bond to each other to form a ring; Y<SB>1</SB>and Y<SB>2</SB>each independently represents alkyl, cycloalkyl or aryl, Y<SB>1</SB>and Y<SB>2</SB>may bond to each other to form a ring; and X<SP>-</SP>represents one of anions represented by formulae (A1)-(A2) wherein R<SB>a1</SB>-R<SB>a5</SB>each independently represents an aliphatic hydrocarbon group, R<SB>a1</SB>and R<SB>a2</SB>may bond to each other to form a ring, and two of R<SB>a3</SB>-R<SB>a5</SB>may bond to each other to form a ring. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is used in semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystals and thermal heads, and other photofabrication processes, planographic printing plates, acid curable compositions, radical curable compositions, and the like. The present invention relates to a positive resist composition, a pattern forming method using the positive resist composition, and a compound used in the positive resist composition.

  The stimuli-sensitive composition is a composition that generates an acid or a radical by an external stimulus, and changes the physical properties of the site to which the stimulus is given by the reaction, and more preferably, irradiation with actinic rays, radiation or heat. It is a pattern forming material for changing the solubility of the part and the non-irradiated part in the developer to form a pattern on the substrate.

  In such a stimulant composition, various acid generators that generate an acid upon irradiation with actinic rays or radiation have been proposed.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 2001-294570) describes a resist composition containing a phenacylsulfonium salt having a ring structure, and Patent Document 2 (Japanese Patent Laid-Open No. 2003-114522) has a chain shape. A resist composition containing a phenacylsulfonium salt having a structure is described. On the other hand, Patent Document 3 (JP 2002-268223) and Patent Document 4 (JP 2003-261529) are disclosed as resist compositions using an acid generator having an imide anion structure as a sulfonium counter.

  However, it is known that the conventional resist composition has a variation in temperature in heating (PEB) with a hot plate after exposure when it is used for a wafer having a large diameter, which affects the obtained pattern. Therefore, it is desired to improve such PEB temperature dependency.

  Further, the conventional resist composition is desired to further improve the resolution and profile of contact holes.

JP 2001-294570 A JP 2003-114522 A JP 2002-268223 A JP 2003-261529 A

Therefore, the object of the present invention is that the PEB temperature dependency is small at an exposure wavelength of 200 nm or less, particularly ArF excimer laser light (193 nm) and F ₂ excimer laser light (157 nm), and the balance of sensitivity, exposure latitude, resolution, and profile is low. It is an object of the present invention to provide a good positive resist composition, a pattern forming method using the positive resist composition, and the positive resist composition.

  The present invention has the following configuration, whereby the above object of the present invention is achieved.

  1. A positive resist composition containing a compound represented by the general formula (S).

In general formula (S),
Ar represents an aryl group.
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ₁ and R ₂ may combine to form a ring.
Y ₁ and Y ₂ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. Y ₁ and Y ₂ may combine to form a ring.
X ⁻ represents any of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring.

  2. 1. The compound represented by the general formula (S) is a compound represented by the general formula (S-1). The positive resist composition as described in 1. above.

In general formula (S-1),
Ar represents an aryl group.
R _1a and R _2a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and at least one of them is not a hydrogen atom. R _1a and R _2a may combine to form a ring.
Y ₁ and Y ₂ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. Y ₁ and Y ₂ may combine to form a ring.
X ⁻ represents any of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring.

  3. 1. The compound represented by the general formula (S) is a compound represented by the general formula (S-2). The positive resist composition as described in 1. above.

In general formula (S-2),
Ar represents an aryl group.
R _1a and R _2a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and at least one of them is not a hydrogen atom. R _1a and R _2a may combine to form a ring.
Y _1b and Y _2b each independently represent an alkyl group, a cycloalkyl group, or an aryl group. Y _1b and Y _2b are not bonded to form a ring.
X ⁻ represents any of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring.

  4). Furthermore, the above-mentioned 1. containing an acid-decomposable resin containing the following monomer unit. ~ 3. The positive resist composition according to any one of the above.

In formula (P1),
R ^p1 represents a hydrogen atom or an alkyl group.
R ^p2 , R ^p3 and R ^p4 each independently represents a hydrogen atom or a hydroxyl group, and at least one of R ^p2 , R ^p3 and R ^p4 represents a hydroxyl group.

  5). Above 1. ~ 4. A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of the above; and exposing and developing the resist film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a positive resist composition having a small PEB temperature dependency and having a good balance of sensitivity, exposure latitude, resolution, and profile, and a pattern forming method using the same.

Hereinafter, the present invention will be described in detail.
In addition, in the description of group (atomic group) in this specification, the description which is not describing 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).

  The positive resist composition of the present invention contains a compound (A) that generates an acid upon irradiation with actinic rays or radiation and a resin (B) that decomposes by the action of the acid and increases the solubility in an alkaline developer. If necessary, it contains a dissolution inhibiting compound (C) having a molecular weight of 3000 or less, which decomposes further by the action of an acid to increase the solubility in an alkaline developer, or generates an acid upon irradiation with actinic rays or radiation. And a dissolution inhibiting compound (C) having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in the alkaline developer.

[1] (A) Compound Represented by General Formula (S) The compound represented by (A) general formula (S) of the present invention is a compound that generates an acid or a radical upon external stimulation (acid generator). ).
A compound that generates an acid or radical by an external stimulus is an infrared ray, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam or other active light, radiation, heat, ultrasonic wave, etc. It is a compound that generates acid or radical upon stimulation.

  In the present invention, the compound represented by the above general formula (I) is used as a compound that generates an acid or a radical by an external stimulus.

In general formula (S),
Ar represents an aryl group.
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ₁ and R ₂ may combine to form a ring.
Y ₁ and Y ₂ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. Y ₁ and Y ₂ may combine to form a ring.
X ⁻ represents any of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring.

  Among general formula (S), (S-1) can be mentioned as an example of a suitable structure.

In general formula (S-1),
R _1a and R _2a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and at least one of them is not a hydrogen atom. R _1a and R _2a may combine to form a ring.
Ar, Y ₁ , Y ₂ and X ⁻ are the same as those in the general formula (S).

  Moreover, (S-2) can also be mentioned as a more suitable example among general formula (S-1).

In general formula (S-2),
Y _1b and Y _2b each independently represent an alkyl group, a cycloalkyl group, or an aryl group. Y _1b and Y _2b are not bonded to form a ring.
R _1a , R _2a , Ar and X ⁻ are the same as those in formula (S-1).

The compound (A) of the present invention has a high photoacid generation ability with respect to light of 200 nm or less, particularly ArF excimer laser light (193 nm) and F ₂ excimer laser light (157 nm). Objects have a large exposure latitude.

The aryl group of Ar, R ₁ , R _2, R _1a , R _2a, Y ₁ , Y ₂ , Y _1b and Y _2b may have a substituent and is an aryl group having 6 to 14 carbon atoms. Are preferable, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group, and a phenyl group and a naphthyl group are more preferable.
The alkyl group in R ₁ , R _2, R _1a , R _2a, Y ₁ , Y ₂ , Y _1b and Y _2b may have a substituent, and may be linear or branched. An alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched group) Butyl group, linear or branched pentyl group), oxoalkyl group, fluoroalkyl group and the like.
The cycloalkyl group in R ₁ , R _2, R _1a , R _2a, Y ₁ , Y ₂ , Y _1b and Y _2b may have a substituent, for example, a cyclic group having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.
Examples of the ring that may be formed by combining R ₁ and R ₂ or R _a1 and R _a2 , or the ring that two of R _{a3 to} R _a5 may be bonded to each other include, for example, carbon An alkylene group having 2 to 8 atoms, preferably a butylene group, a pentylene group and a hexylene group, particularly preferably a butylene group and a pentylene group can be mentioned. Further, the formed ring may contain a hetero atom.
Examples of the cyclic group that may be formed together with S ⁺ in the general formula (S) by combining Y ₁ and Y ₂ include an alkylene group having 2 to 10 carbon atoms, preferably a butylene group, A pentylene group and a hexylene group, particularly preferably a butylene group and a pentylene group can be mentioned. Further, the formed ring may contain a hetero atom.
The aliphatic hydrocarbon group for R _{a1 to} R _a5 is preferably a linear or branched alkyl group, cycloalkyl group, or aryl group, and may have a substituent. More preferably, it is an alkyl group having fluorine as a substituent, and more preferably, any two of R _a1 , R _a2 and R _{a3 to} R _a5 are bonded to each other to form a ring structure.

  Each of the above groups may be unsubstituted or may further have a substituent. As further substituents, for example, nitro group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group, hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 5 carbon atoms), An aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably And the like. As for the aryl group and ring structure of each group, examples of the substituent further include an alkyl group (preferably having 1 to 20 carbon atoms).

  Although the preferable specific example of the compound (A) of this invention is shown below, this invention is not limited to these.

  A compound (A) can be used individually by 1 type or in combination of 2 or more types.

  The compound (A) can be obtained by reacting the corresponding 2-halogen-substituted ketone and sulfide compound in the presence of no catalyst or silver catalyst to synthesize a sulfonium skeleton, and salt-exchange this with the corresponding anion. As another synthesis method, a corresponding ketone derivative is reacted with a trialkylsilyl halide under basic conditions to form a silyl enol ether, and this is reacted with a sulfoxide to synthesize a sulfonium skeleton, which is combined with a corresponding anion. Obtained by salt exchange. Or it can synthesize | combine by the method as described in Unexamined-Japanese-Patent No. 2002-268223 and Unexamined-Japanese-Patent No. 2002-341539.

  The content of the compound (A) in the positive resist composition of the present invention is preferably 0.1% by mass to 20% by mass, more preferably 1.0% by mass to 15% by mass, based on the solid content of the composition. %, More preferably 3.0% by mass to 10% by mass.

(Combination acid generator)
In the present invention, in addition to the compound (A), a compound that decomposes upon irradiation with actinic rays or radiation to generate an acid may be used in combination.

  The amount of the photoacid generator that can be used in combination is usually 100/0 to 20/80, preferably 100/0 to 40/60, and more preferably in molar ratio (compound (A) / other acid generator). 100/0 to 50/50.

  As such photoacid generators that can be used in combination, they are used in photocationic photoinitiators, photoinitiators of radical photopolymerization, photodecolorants of dyes, photochromic agents, or microresists. Known compounds that generate acids upon irradiation with actinic rays or 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, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (I).

The organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

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 (Z1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (Z1) is at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (Z1) It may be a compound.

  As more preferred (Z1) component, compounds (Z1-1), (Z1-2), and (Z1-3) described below can be exemplified.

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

In the 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, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, aryldicycloalkylsulfonium compounds, and arylalkylcycloalkylsulfonium compounds.

  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, A sec-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, three to 15 carbon atoms), an aryl group (e.g., having 6 carbon atoms To 14), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, most preferably 1 to 4 alkyl groups and 1 to 4 carbon atoms alkoxy groups. 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 (Z1-2) will be described.

Compound (Z1-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (Z1) 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 is generally from 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, more preferably a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylmethyl group, A 2-oxoalkyl group is preferred.

The alkyl group as R _{201 to} R ₂₀₃ may be linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. Group, butyl group, pentyl group and the like. The alkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxoalkyl group, an alkoxycarbonylmethyl group are more preferable. The 2-oxoalkyl group may be linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable. The alkoxy group in the alkoxycarbonylmethyl group as R _{201 to} R ₂₀₃ is preferably an alkoxy group having 1 to 5 carbon atoms.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a number of 3 to 10 cycloalkyl group having a carbon, e.g., cyclopentyl, cyclohexyl group and a norbornyl group. The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable. Examples of the 2-oxocycloalkyl group include a group having> C═O at the 2-position of the above cycloalkyl group.

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, 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 (Z1-3) is a compound represented by the following general formula (Z1-3), and is a compound having a phenacylsulfonium salt structure.

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.

  Rx and Ry each independently represents an alkyl group, a cycloalkyl 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.

Zc ^- represents a non-nucleophilic anion, in the general formula (I) X ^- can be the same as the non-nucleophilic anion.

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

The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include 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 chain having 1 to 5 carbon atoms. And a branched alkoxy group (for example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), cyclic alkoxy group having 3 to 8 carbon atoms (for example, cyclopentyl) Oxy group, cyclohexyloxy group).

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

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _5c . The alkyl group as R _x and R _y is preferably a 2-oxoalkyl group or an alkoxycarboxymethyl group. 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 cycloalkyl group as R _x and R _y include the same cycloalkyl groups as R _{1c to} R _5c . The cycloalkyl group as R _x and R _y is preferably a 2-oxocycloalkyl group. Examples of the 2-oxocycloalkyl group include a group having> C═O at the 2-position of the cycloalkyl group 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 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.

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 as R ₂₀₄ to R ₂₀₇ is preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, for example, include methyl group, ethyl group, propyl group, butyl group, a pentyl group, etc. be able to.

The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a number of 3 to 10 cycloalkyl group having a carbon, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.

The R ₂₀₄ to R ₂₀₇ substituents which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, three to 15 carbon atoms), an aryl group (e.g., carbon atoms 6 to 15), an alkoxy group (for example, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as 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 represents an aryl group.

R ₂₀₆ , R ₂₀₇ and R _{208 each} represents an alkyl group, a cycloalkyl group or an aryl group.

  A represents an alkylene group, an alkenylene group or an arylene group.

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

  Examples of particularly preferable compounds among the compounds that are decomposed by irradiation with actinic rays or radiation that may be used in combination are listed below.

[2] (B) Resin that decomposes by the action of an acid and increases the solubility in an alkaline developer (hereinafter also referred to as “component (B)”)
As a resin that is decomposed by an acid used in the positive resist composition of the present invention and has increased solubility in an alkaline developer, the main chain or side chain of the resin, or both the main chain and the side chain may have an acid. It is a resin having a group (hereinafter also referred to as an “acid-decomposable group”) that can be decomposed by. Among these, a resin having a group capable of decomposing with an acid in the side chain is more preferable.

A group preferable as a group that can be decomposed by an acid is a group in which a hydrogen atom of a —COOH group or —OH group is substituted with a group capable of leaving with an acid.
In the present invention, the acid-decomposable group is an acetal group or a tertiary ester group.

  The base resin in the case where these acid-decomposable groups are bonded as side chains is an alkali-soluble resin having —OH or —COOH groups in the side chains. For example, the alkali-soluble resin mentioned later can be mentioned.

The alkali dissolution rate of these alkali-soluble resins is preferably 170 A / second or more as measured with 0.261 N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferred is 330 A / second or more (A is angstrom).
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). Hydroxystyrene structural units such as a part of poly (hydroxystyrene), O-alkylated or O-acylated product, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, hydrogenated novolak resin, etc. It is an alkali-soluble resin.

  Preferred examples of the repeating unit having an acid-decomposable group in the present invention include t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, (meth) acrylic acid tertiary alkyl ester and the like.

  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.

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

  p-t-butoxystyrene / p-hydroxystyrene copolymer, p- (t-butoxycarbonyloxy) styrene / p-hydroxystyrene copolymer, p- (t-butoxycarbonylmethyloxy) styrene / p-hydroxystyrene Copolymer, 4- (t-butoxycarbonylmethyloxy) -3-methylstyrene / 4-hydroxy-3-methylstyrene copolymer, p- (t-butoxycarbonylmethyloxy) styrene / p-hydroxystyrene (10 % Hydrogenated) copolymer, m- (t-butoxycarbonylmethyloxy) styrene / m-hydroxystyrene copolymer, o- (t-butoxycarbonylmethyloxy) styrene / o-hydroxystyrene copolymer, p -(Cumyloxycarbonylmethyloxy) styrene / p-hydroxy Tylene copolymer, cumyl methacrylate / methyl methacrylate copolymer, 4-t-butoxycarbonylstyrene / dimethyl maleate copolymer, benzyl methacrylate / tetrahydropyranyl methacrylate, p- (t-butoxycarbonylmethyloxy) styrene / p-hydroxystyrene / styrene copolymer, pt-butoxystyrene / p-hydroxystyrene / fumaronitrile copolymer, tert-butoxystyrene / hydroxyethyl methacrylate copolymer, styrene / N- (4-hydroxyphenyl) maleimide / N- (4-t-butoxycarbonyloxyphenyl) maleimide copolymer, p-hydroxystyrene / t-butyl methacrylate copolymer, styrene / p-hydroxystyrene / t-butyl methacrylate copolymer P-hydroxystyrene / t-butyl acrylate copolymer, styrene / p-hydroxystyrene / t-butyl acrylate copolymer, p- (t-butoxycarbonylmethyloxy) styrene / p-hydroxystyrene / N-methylmaleimide Copolymer, t-butyl methacrylate / 1-adamantylmethyl methacrylate copolymer, p-hydroxystyrene / t-butyl acrylate / p-acetoxystyrene copolymer, p-hydroxystyrene / t-butyl acrylate / p- (t -Butoxycarbonyloxy) styrene copolymer, p-hydroxystyrene / t-butyl acrylate / p- (t-butoxycarbonylmethyloxy) styrene copolymer,

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

  The content of the group that can be decomposed by an acid is determined by the number of groups (B) that can be decomposed by an acid in the resin and the number of alkali-soluble groups that are not protected by a group capable of leaving by an acid (S). B + S). The content is preferably 0.01 to 0.7, more preferably 0.05 to 0.50, and still more preferably 0.05 to 0.40.

  When irradiating the positive resist composition of the present invention with ArF excimer laser light, the resin of component (B) has a monocyclic or polycyclic alicyclic hydrocarbon structure, and is decomposed by the action of an acid. A resin that increases the solubility in an alkali developer is preferred.

  As a resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposes by the action of an acid, and increases its solubility in an alkaline developer (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) , At least selected from the group consisting of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) and repeating units represented by the following general formula (II-AB) It is preferable that it is resin containing 1 type.

(Wherein 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 represents an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to form.
R ₁₂ to R ₁₆ each independently having 1 to 4 carbons, a linear or branched alkyl group or alicyclic hydrocarbon group, provided that at least one of R ₁₂ to R _14, Alternatively, either R ₁₅ or R ₁₆ represents 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 One 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 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 _{22 to} R ₂₅ One represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring. )

In formula (II-AB):
R ₁₁ ′ and R ₁₂ ′ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Z ′ represents an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and may have a substituent.

  The general formula (II-AB) is more preferably the following general formula (II-A) or general formula (II-B).

In formulas (II-A) and (II-B):
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent.
Here, R ₅ represents an alkyl group, a cyclic hydrocarbon group, or the following —Y group, which may have a substituent.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring. n represents 0 or 1.
R ₁₇ ′ is —COOH, —COOR ₅ , —CN, a hydroxyl group, an optionally substituted alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or -Y group is represented.
R ₆ represents an alkyl group or a cyclic hydrocarbon group which may have a substituent.
The -Y group;

(In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an optionally substituted alkyl group. A and b represent 1 or 2.)

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 (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group. Carboxy group, alkoxycarbonyl group, nitro group and the like.

The alicyclic hydrocarbon group in R _{11 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 number of carbon atoms is preferably 6 to 30, and particularly preferably 7 to 25 carbon atoms. These alicyclic hydrocarbon groups may have a substituent.

  Preferred examples of the alicyclic hydrocarbon group 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, a cycloheptyl group, and a cyclooctyl group. 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 substituted 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, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Represent. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy 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 structures represented by the general formulas (pI) to (pVI) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.
Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.
As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the above resin, the hydrogen atom of the carboxyl group is preferably substituted with the structure represented by the general formula (pI) to (PVI). Structure.

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A is a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group. Represents a combination of groups.
Ra represents any group of the above formulas (pI) to (pVI).

  The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Specific examples of the repeating unit represented by the general formula (pA) are shown below.

In the general formula (II-AB), R ₁₁ ′ and R ₁₂ ′ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group which may have a substituent.
Z ′ represents an atomic group for forming an alicyclic structure which contains two bonded carbon atoms (C—C) and may have a substituent.

Examples of the halogen atom in R ₁₁ ′ and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
As the alkyl group in R ₁₁ ′, R ₁₂ ′, and R ₂₁ ′ to R ₃₀ ′, a linear or branched alkyl group having 1 to 10 carbon atoms is preferable, and more preferably 1 to 6 carbon atoms. Linear or branched alkyl groups, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

  Examples of the further substituent in the above alkyl group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. 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 acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.
Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pVI).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B).
Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (II-A) or (II-B) is more preferable.

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the acid-decomposable group may be contained in the aforementioned —C (═O) —XA′—R ₁₇ ′, or may be represented by the general formula (II— It may be included as a substituent for Z ′ in AB).
The structure of the acid-decomposable group is represented by —C (═O) —X ₁ —R ₀ .
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ has the same meaning as X above.

Examples of the halogen atom in R ₁₃ ′ to R ₁₆ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

The alkyl group in R ₅ , R ₆ , R ₁₃ ′ to R ₁₆ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. It is a linear or branched alkyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

Examples of the cyclic hydrocarbon group in R ₅ , R ₆ and R ₁₃ ′ to R ₁₆ ′ include a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, 2- List methyl-2-adamantyl group, norbornyl group, boronyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group, etc. Can do.
Examples of the ring formed by combining at least two of R ₁₃ ′ to R ₁₆ ′ include rings having 5 to 12 carbon atoms such as cyclopentene, cyclohexene, cycloheptane, and cyclooctane.

Examples of the alkoxy group for R ₁₇ ′ 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 further substituents in the alkyl group, cyclic hydrocarbon group, and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, an alkyl group, and a cyclic hydrocarbon group. Can do. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. 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 acyl group include a formyl group and an acetyl group. Examples of the group include an acetoxy group.
Examples of the alkyl group and cyclic hydrocarbon group include those listed above.

  The divalent linking group of A ′ is selected from the group consisting of an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Single or a combination of two or more groups may be mentioned.

  In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI). It can be contained in at least one kind of repeating unit among the repeating unit having, the repeating unit represented by formula (II-AB), and the repeating unit of the copolymerization component described later.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or the general formula (II-B) are atomic groups for forming an alicyclic structure in the general formula (II-AB). Or it becomes a substituent of atomic group Z for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-A) or the general formula (II-B) include the following, but the present invention is not limited to these specific examples.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a lactone group, and more preferably any of the following general formulas (Lc) and general formulas (V-1) to (V-5) below. It has a repeating unit having a group having a lactone structure represented, and the group having a lactone structure may be directly bonded to the main chain.

In general formula (Lc), Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ , and Re ₁ each independently represent a hydrogen atom or an alkyl group that may have a substituent. m and n each independently represents an integer of 0 to 3, and m + n is 2 or more and 6 or less.

In the general formulas (V-1) to (V-5), R _{1b to} R _5b each independently represent a hydrogen atom or an optionally substituted alkyl group, cycloalkyl group, alkoxy group, alkoxy group. A carbonyl group, an alkylsulfonylimino group or an alkenyl group is represented. Two of R _{1b to} R _5b may combine to form a ring.

R _{1 to} Re ₁ alkyl groups in general formula (Lc) and R _{1b to} R _5b alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkyl groups in general formulas (V-1) to (V-5) Examples of the alkyl group in the sulfonylimino group include linear and branched alkyl groups, which may have a substituent.

As the repeating unit having a group having a lactone structure represented by the general formula (Lc) or any one of the general formulas (V-1) to (V-5), the above general formula (II-A) or (II- B) wherein at least one of R ₁₃ ′ to R ₁₆ ′ has a group represented by general formula (Lc) or general formula (V-1) to (V-5) (for example, R in —COOR ₅ ) ₅ represents a group represented by general formula (Lc) or general formulas (V-1) to (V-5)), or a repeating unit represented by the following general formula (AI).

In general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. As a preferable substituent that the alkyl group of R _b0 may have, as a preferable substituent that the alkyl group as R _1b in the general formulas (V-1) to (V-5) may have. What was illustrated previously is mentioned.
Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _b0 is preferably a hydrogen atom.
A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.
B ₂ represents a group represented by any one of general formula (Lc) and general formulas (V-1) to (V-5).

  Specific examples of the repeating unit having a group having a lactone structure are shown below, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may contain a repeating unit having a group represented by the following general formula (VII).

In general formula (VII), R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group.

  The group represented by the general formula (VII) is preferably a dihydroxy form or a monohydroxy form, and more preferably a dihydroxy form.

As the repeating unit having a group represented by the general formula (VII), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B) is the above general formula (VII). ) (For example, R _{5 of} —COOR ₅ represents a group represented by the general formula (VII)), or a repeating unit represented by the following general formula (AII). it can.

In general formula (AII), R ₁ c represents a hydrogen atom or a methyl group.
R ₂ c to R ₄ c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group. _{Two of} R ₂ c to R ₄ c are preferably hydroxyl groups.

  Although the specific example of the repeating unit which has a structure represented by general formula (AII) below is given, it is not limited to these.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may contain a repeating unit represented by the following general formula (VIII).

In the general formula (VIII), Z ₂ represents —O— or —N (R ₄₁ ) —. Here, R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue.

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but are not limited thereto.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
Thereby, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition point),
(3) Alkali developability,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.
As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

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

  In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin of the present invention include the following.
(1) Containing a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) (side chain type)
(2) Containing repeating unit represented by general formula (II-AB) (main chain type)
However, in (2), for example, the following can be further mentioned.
(3) A repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type)

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 mol% to 60 mol%, more preferably 20 mol% to 50 mol% in all repeating structural units. More preferably, it is 25 mol%-40 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) is 30 mol% in all the repeating structural units. -70 mol% is preferable, More preferably, it is 35 mol%-65 mol%, More preferably, it is 40% mol-60 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 mol% to 60 mol%, more preferably 15 mol% in all repeating structural units. It is -55 mol%, More preferably, it is 20 mol%-50 mol%.

In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To 99 p% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon represented by (pVI) and the repeating unit represented by the general formula (II-AB). The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.
When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and if necessary, a reaction solvent such as ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, A ketone such as methyl isobutyl ketone, an ester solvent such as ethyl acetate, and the composition of the present invention such as propylene glycol monomethyl ether acetate described below are dissolved in a solvent that dissolves uniformly and then nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an inert gas atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50 ° C to 100 ° C.

When the composition of the present invention is used for the upper resist of the multilayer resist, the resin as the component (B) preferably has a silicon atom.
As the resin having a silicon atom and decomposing by the action of an acid to increase the solubility in an alkaline developer, any of resins having a silicon atom in at least one of a main chain and a side chain can be used. Examples of the resin having a siloxane structure in the side chain of the resin include, for example, an olefin monomer having a silicon atom in the side chain, maleic anhydride and a (meth) acrylic acid monomer having an acid-decomposable group in the side chain. Mention may be made of copolymers.

When the positive resist composition of the present invention is irradiated with F ₂ excimer laser light, the resin of component (B) has a structure in which fluorine atoms are substituted on the main chain and / or side chain of the polymer skeleton, and A resin that decomposes by the action of an acid and increases the solubility in an alkaline developer (hereinafter also referred to as a fluorine group-containing resin) is preferred, and more preferably, a hydroxyl group substituted with a fluorine atom or a fluoroalkyl group at the 1-position or the 1-position A resin containing a group in which a hydroxyl group substituted with a fluorine atom or a fluoroalkyl group is protected with an acid-decomposable group, and most preferably a hexafluoro-2-propanol structure or a hydroxyl group of hexafluoro-2-propanol is protected with an acid-decomposable group It is a resin containing a structure. By introducing fluorine atoms, it is possible to improve transparency to far ultraviolet light, particularly F ₂ (157 nm) light.

  (B) Preferred examples of the fluorine group-containing resin in the acid-decomposable resin include resins having at least one repeating unit represented by the following general formulas (FA) to (FG).

In the general formula,
R _{100 to} R ₁₀₃ each represents a hydrogen atom, a fluorine atom, an alkyl group, a fluoroalkyl group or an aryl group.
R ₁₀₄ and R ₁₀₆ are each a hydrogen atom, a fluorine atom or a fluoroalkyl group, and at least one of R ₁₀₄ and R ₁₀₆ is a fluorine atom or a fluoroalkyl group. R ₁₀₄ and R ₁₀₆ are preferably both trifluoromethyl groups.
R ₁₀₅ is a hydrogen atom, an alkyl group, a fluoroalkyl group, an acyl group, an alkoxycarbonyl group or a group that decomposes under the action of an acid.
A ₁ is a single bond, a divalent linking group, for example, a linear, branched, cyclic alkylene group, alkenylene group, arylene group, —OCO—, —COO—, or —CON (R ₂₄ ) —, and of these It is a linking group containing a plurality. R ₂₄ is a hydrogen atom or an alkyl group.
R ₁₀₇ and R ₁₀₈ are each a hydrogen atom, a halogen atom, an alkyl group, a fluoroalkyl group, an alkoxy group, an alkoxycarbonyl group or a group that decomposes under the action of an acid.
R ₁₀₉ is a hydrogen atom, an alkyl group, a fluoroalkyl group, or a group that decomposes under the action of an acid.
b is 0, 1 or 2;
The repeating units represented by the general formulas (FA) to (FG) contain at least one, preferably three or more fluorine atoms per one repeating unit.

In the general formulas (FA) to (FG), the alkyl group is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, and an n-butyl group. , Sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, fluoroalkyl group (perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, perfluorooctylethyl group, perfluorododecyl group, etc.), haloalkyl Preferred examples include groups (chloromethyl group, chloroethyl group, chloropropyl group, chlorobutyl group, bromomethyl group, bromoethyl group, etc.).
The cycloalkyl group may be monocyclic or polycyclic. The monocyclic type has 3 to 8 carbon atoms, and preferred examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. The polycyclic type has 6 to 20 carbon atoms. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetocyclododecyl group Preferred examples include an androstanyl group. However, the carbon atom in the monocyclic or polycyclic cycloalkyl group may be substituted with a heteroatom such as an oxygen atom.

As the aryl group, for example, an aryl group having 6 to 15 carbon atoms, specifically, 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, for example, an aralkyl group having 7 to 12 carbon atoms, specifically, a benzyl group, a phenethyl group, a naphthylmethyl group, and the like can be preferably exemplified.
As an alkenyl group, it is a C2-C8 alkenyl group, for example, Specifically, a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group can be mentioned preferably.

As the alkoxy group, for example, an alkoxy group having 1 to 8 carbon atoms, specifically, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, a butoxy group, a pentoxy group, an allyloxy group, An octoxy group etc. can be mentioned preferably.
As the acyl group, for example, an acyl group having 1 to 10 carbon atoms, specifically, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group, an octanoyl group, a benzoyl group, and the like are preferable. Can do.
The acyloxy group is preferably an acyloxy group having 2 to 12 carbon atoms, and examples thereof include an acetoxy group, a propionyloxy group, and a benzoyloxy group.
The alkynyl group is preferably an alkynyl group having 2 to 5 carbon atoms, and examples thereof include an ethynyl group, a propynyl group, and a butynyl group.
Examples of the alkoxycarbonyl group include i-propoxycarbonyl group, t-butoxycarbonyl group, t-amyloxycarbonyl group, 1-methyl-1-cyclohexyloxycarbonyl group and the like, preferably secondary, more preferably tertiary alkoxycarbonyl. Groups.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkylene group include those having 1 to 8 carbon atoms such as a methylene group, ethylene group, propylene group, butylene group, hexylene group, and octylene group, which may have a substituent.
The alkenylene group is preferably an alkenylene group having 2 to 6 carbon atoms, such as an optionally substituted ethenylene group, propenylene group, butenylene group.
Preferred examples of the cycloalkylene group include those having 5 to 8 carbon atoms such as a cyclopentylene group and a cyclohexylene group which may have a substituent.
The arylene group is preferably an arylene group having 6 to 15 carbon atoms such as an optionally substituted phenylene group, tolylene group or naphthylene group.

These groups may have a substituent. Examples of the substituent include activities such as alkyl group, cycloalkyl group, aryl group, amino group, amide group, ureido group, urethane group, hydroxyl group, and carboxyl group. Those having hydrogen, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), thioether group, acyl group (acetyl group, propanoyl group) Benzoyl group, etc.), acyloxy group (acetoxy group, propanoyloxy group, benzoyloxy group etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group etc.), cyano group, nitro group, etc. .
Here, examples of the alkyl group, cycloalkyl group, and aryl group include those described above, but the alkyl group may be further substituted with a fluorine atom or a cycloalkyl group.

Fluorine-containing are contained in the resin of the present invention, examples of the group in a disassembled alkali solubility by the action of an acid, for example, _{-O-C (R 36) (} R 37) (R 38), - O-C (R 36 ) (R ₃₇ ) (OR ₃₉ ), —O—COO—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —O—C (R ₀₁ ) (R ₀₂ ) COO—C (R ₃₆ ) (R _{37) (R 38), -} COO-C (R 36) (R 37) (R 38), - COO-C (R 36) (R 37) (OR 39) , and the like.
R _{36 to} R ₃₉ represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group which may have a substituent, and R ₀₁ and R _{02 each} have a hydrogen atom or a substituent. And an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group, which may be present.

  Preferable specific examples include t-butyl group, t-amyl group, 1-alkyl-1-cyclohexyl group, 2-alkyl-2-adamantyl group, 2-adamantyl-2-propyl group, 2- (4-methylcyclohexyl). ) Ether group or ester group of tertiary alkyl group such as 2-propyl group, acetal group or acetal ester group such as 1-alkoxy-1-ethoxy group, tetrahydropyranyl group, t-alkyl carbonate group, t-alkyl A carbonylmethoxy group etc. are mentioned preferably.

  Specific examples of the repeating structural units represented by the general formulas (FA) to (FG) are shown below, but the present invention is not limited thereto.

  The total content of the repeating units represented by the general formulas (FA) to (FG) is generally 10 mol% to 80 mol%, preferably 30 mol% to 70 mol, based on all repeating units constituting the resin. %, More preferably in the range of 35 mol% to 65 mol%.

  In addition to the above repeating structural units, the resin of the present invention (B) may be copolymerized with other polymerizable monomers for the purpose of further improving the performance of the resist of the present invention.

Examples of copolymerizable monomers that can be used include those shown below.
For example, an addition polymerizable unsaturated bond selected from acrylic acid esters, acrylamides, methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic acid esters other than the above. A compound having one.

Such a fluorine-containing resin may contain other repeating units as a copolymerization component in addition to the repeating unit having fluorine atoms, from the viewpoint of improving dry etching resistance, adjusting alkali solubility, and improving substrate adhesion. preferable. Preferred as other repeating units are:
1) A repeating unit having an alicyclic hydrocarbon structure represented by the general formulas (pI) to (pVI) and (II-AB). Specifically, the repeating units 1 to 23 and the repeating units [II-1] to [II-32]. Of the above specific examples 1 to 23, Rx is preferably CF ₃ .
2) A repeating unit having a lactone structure represented by the general formulas (Lc) and (V-1) to (V-5). Specifically, the repeating units (IV-1) to (IV-16) and the repeating units (Ib-1) to (Ib-11).
3) The following general formula (XV) (XVI) (XVII) derived from a maleic anhydride, vinyl ether or a vinyl compound having a cyano group, specifically the repetitions listed in (C-1) to (C-15) unit.
Is mentioned. These other repeating units may or may not contain a fluorine atom.

In the formula, R ₄₁ represents an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group.
R ₄₂ represents a hydrogen atom, a halogen atom, a cyano group or an alkyl group.
A ₅ is a single bond, a divalent alkylene group, an alkenylene group, a cycloalkylene group or an arylene group, or —O—CO—R ₂₂ —, —CO—O—R ₂₃ —, —CO—N (R ₂₄ ) —. R ₂₅ -is represented.
R ₂₂ , R ₂₃ and R ₂₅ may be the same or different and each may have a single bond, an ether group, an ester group, an amide group, a urethane group or a ureido group, a divalent alkylene group, an alkenylene group Represents a cycloalkylene group or an arylene group.
R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group which may have a substituent.
n represents 0 or 1, and x, y, z represents an integer of 0 to 4.
Here, examples of each substituent include those similar to the substituents of the general formulas (FA) to (FG).

  Moreover, although the specific example of the repeating structural unit represented by general formula (XVI)-(XVII) is shown, this invention is not limited to this.

  The content of other repeating units such as the repeating units represented by the general formulas (XV) to (XVII) is generally 0 mol% to 70 mol%, preferably 10 mol%, based on all repeating units constituting the resin. It is used in a range of ˜60 mol%, more preferably 20 mol% to 50 mol%.

(B) The fluorine group-containing resin as the acid-decomposable resin may contain an acid-decomposable group in any repeating unit.
The content of the repeating unit having an acid-decomposable group is preferably from 10 mol% to 70 mol%, more preferably from 20 mol% to 60 mol%, still more preferably from 30 mol% to 60 mol, based on all repeating units. %.

  The fluorine group-containing resin can be synthesized by radical polymerization in substantially the same manner as the alicyclic hydrocarbon-based acid-decomposable resin.

  The weight average molecular weight of the resin of the component (B) according to the present invention is preferably 1,000 to 200,000 as a polystyrene conversion value by the GPC method. It is preferable for the weight average molecular weight to be in the above-mentioned range in order to satisfy both the heat resistance and dry etching resistance, and the developability and film forming performance.

  In the positive resist composition of the present invention, the blending amount of the resin of the component (B) according to the present invention in the whole composition is preferably 40% by mass to 99.99% by mass, more preferably 50% by mass. It is mass%-99.97 mass%.

[3] (C) Dissolution-inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as “(C) component” or “dissolution-inhibiting compound”) that is decomposed by the action of an acid to increase the solubility in an alkaline developer.
(C) As a dissolution inhibiting compound having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer, the permeability of 220 nm or less is not lowered, so Proceeding of SPIE, 2724, 355 (1996). Preference is given to alicyclic or aliphatic compounds containing acid-decomposable groups, such as the cholic acid derivatives containing acid-decomposable groups described. Examples of the acid-decomposable group and alicyclic structure are the same as those described above for the alicyclic hydrocarbon-based acid-decomposable resin.
When the positive resist composition of the present invention is exposed with a KrF excimer laser or irradiated with an electron beam, it preferably contains a structure in which the phenolic hydroxyl group of the phenol compound is substituted with an acid-decomposable group. As the phenol compound, those containing 1 to 9 phenol skeletons are preferred, and those containing 2 to 6 are more preferred.
The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibiting compound is preferably 3% by mass to 50% by mass and more preferably 5% by mass to 40% by mass with respect to the solid content of the positive resist composition.

  Specific examples of the dissolution inhibiting compound are shown below, but are not limited thereto.

[4] (D) Resin soluble in alkali developer (hereinafter also referred to as “component (D)” or “alkali-soluble resin”)
The alkali dissolution rate of the alkali-soluble resin is preferably 20 測定 / sec or more as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferred is 200 Å / sec or more (Å is angstrom).

  Examples of the alkali-soluble resin used in the present invention include novolak resin, hydrogenated novolac resin, acetone-pyrogalol resin, o-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene, hydrogenated polyhydroxystyrene, halogen. Alternatively, alkyl-substituted polyhydroxystyrene, hydroxystyrene-N-substituted maleimide copolymer, o / p- and m / p-hydroxystyrene copolymer, partially O-alkylated product of hydroxyl group of polyhydroxystyrene (for example, 5 mol) % To 30 mol% of O-methylated product, O- (1-methoxy) ethylated product, O- (1-ethoxy) ethylated product, O-2-tetrahydropyranylated product, O- (t-butoxycarbonyl) methylated product Or an O-acylated product (for example, 5 mol) ˜30 mol% O-acetylated product, O- (t-butoxy) carbonylated product, etc.), styrene-maleic anhydride copolymer, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, Examples thereof include, but are not limited to, carboxyl group-containing methacrylic resins and derivatives thereof, and polyvinyl alcohol derivatives.

Particularly preferred alkali-soluble resins are novolak resins and O-polyhydroxystyrene, m-polyhydroxystyrene, p-polyhydroxystyrene and copolymers thereof, alkyl-substituted polyhydroxystyrene, partially O-alkylated polyhydroxystyrene, 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.

  Moreover, the weight average molecular weight of alkali-soluble resin is 2000 or more, Preferably it is 5000-200000, More preferably, it is 5000-100000.

Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.
These (D) alkali-soluble resins in the present invention may be used in combination of two or more.
The usage-amount of alkali-soluble resin is 40 mass%-97 mass% with respect to solid content of the whole composition of a positive resist composition, Preferably it is 60 mass%-90 mass%.

[5] (E) Basic compound The positive resist composition of the present invention preferably contains (E) a basic compound in order to reduce a 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 may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, or 6 carbon atoms. Represents -20 substituted or unsubstituted aryl groups, wherein R ²⁵¹ and R ²⁵² may combine with each other to form a ring.
The alkyl group may be unsubstituted or have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 6 carbon atoms and an alkyl group having 1 to 6 carbon atoms. A hydroxyalkyl group is preferred.
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, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group and cyano group.

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

[6] (F) 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). , A surfactant containing both a fluorine atom and a silicon atom), or preferably two or more thereof.
When the positive resist composition of the present invention contains fluorine and / or a silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.
Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, 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 linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

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

[7] (G) Organic solvent The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent.
Examples of the organic solvent that can be used include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl. Ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N -Dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.

In the present invention, the organic solvent may be used alone or in combination, but it is preferable to use a mixed solvent 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.

<Other additives>
The positive resist composition of the present invention further contains a dye, a plasticizer, a surfactant other than the component (F), a photosensitizer, a compound that promotes solubility in a developer, and the like as necessary. Can be made.
The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.
A preferable addition amount of these dissolution promoting compounds is 2% by mass to 50% by mass, and more preferably 5% by mass to 30% by mass with respect to the resins of the components (B) and (D). From the standpoint of development residue and pattern deformation during development, 50% by mass or less is preferable.

Such a phenol compound having a molecular weight of 1000 or less can be easily synthesized by those skilled in the art with reference to the methods described in, for example, JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. can do.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

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

≪How to use≫
The positive resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
For example, a positive resist composition is applied on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit device by an appropriate application method such as a spinner or a coater.
After the application, actinic rays and radiation are irradiated through a predetermined mask, followed by baking and development. In this way, a good pattern can be obtained. Examples of the actinic ray and radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), an F ₂ excimer laser (157 nm), an X-ray, an electron beam, etc. are preferable, and an ArF excimer laser and an F ₂ excimer laser are most preferable.

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

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

<Synthesis Example of Resin (B)>
Synthesis Example 1 Synthesis of Resin (1) (Side Chain Type)
2-ethyl-2-adamantyl methacrylate and butyrolactone methacrylate were charged at a ratio of 55/45 and dissolved in methyl ethyl ketone / tetrahydrofuran = 5/5 to prepare 100 mL of a 20% solid content solution. To this solution, 2 mol% of Wako Pure Chemical polymerization initiator V-65 was added, and this was added dropwise to 10 mL of methyl ethyl ketone heated to 60 ° C. over 4 hours in a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated for 4 hours, 1 mol% of V-65 was added again, and the mixture was stirred for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and the resin (1) which was a white powder crystallized and precipitated in 3 L of a mixed solvent of distilled water / ISO propyl alcohol = 1/1 was recovered.

^The polymer composition ratio determined from ¹³ CNMR was 46/54. Moreover, the standard polystyrene conversion mass mean molecular weight calculated | required by GPC measurement was 10700.

  Resins (2) to (12) and (26) to (31) were synthesized in the same manner as in Synthesis Example 1.

Synthesis Example 2 Synthesis of Resin (13) (Main Chain Type)
Norbornenecarboxylic acid tbutyl ester, norbornenecarboxylic acid butyrolactone ester, maleic anhydride (molar ratio 40/10/50) and THF (reaction temperature 60 mass%) were charged into a separable flask and heated at 60 ° C. under a nitrogen stream. When the reaction temperature was stabilized, 2 mol% of a radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to initiate the reaction. Heated for 12 hours. The resulting reaction mixture was diluted twice with tetrahydrofuran and then poured into a mixed solution of hexane / isopropyl alcohol = 1/1 to precipitate a white powder. The precipitated powder was filtered out and dried to obtain the desired resin (13).

  When the molecular weight analysis by GPC of the obtained resin (13) was tried, it was 8300 (mass average) in terms of polystyrene. Further, from the NMR spectrum, it was confirmed that the molar ratio of norbornenecarboxylic acid tbutyl ester / norbornenecarboxylic acid butyrolactone ester / maleic anhydride repeating unit of the resin (1) was 42/8/50.

  Resins (14) to (19) were synthesized in the same manner as in Synthesis Example 2.

Synthesis Example 3 Synthesis of Resin (20) (Hybrid Type)
Norbornene, maleic anhydride, t-butyl acrylate and 2-methylcyclohexyl-2-propyl acrylate were charged into a reaction vessel at a molar ratio of 35/35/20/10 and dissolved in tetrahydrofuran to prepare a solution having a solid content of 60%. . This was heated at 65 ° C. under a nitrogen stream. When the reaction temperature was stabilized, 1 mol% of radical initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to initiate the reaction. After heating for 8 hours, the reaction mixture was diluted 2 times with tetrahydrofuran and then poured into hexane having a volume 5 times that of the reaction mixture to precipitate a white powder. The precipitated powder was filtered out, dissolved in methyl ethyl ketone, reprecipitated in a 5-fold volume of hexane / t-butyl methyl ether = 1/1 mixed solvent, and the precipitated white powder was collected by filtration, dried and dried. Resin (20) which is a thing was obtained.

  When the molecular weight analysis by GPC of the obtained resin (20) was tried, it was 12100 (mass average) in terms of polystyrene. From the NMR spectrum, the composition of the resin (1) was norbornene / maleic anhydride / tbutyl acrylate / 2-methylcyclohexyl-2-propyl acrylate according to the present invention in a molar ratio of 32/39/19/10.

  Resins (21) to (25) were synthesized in the same manner as in Synthesis Example 3.

  Hereinafter, the structures and molecular weights of the resins (1) to (31) are shown.

<Fluorine group-containing resin>
Hereinafter, the structures of the fluorine group-containing resins (FII-1) to (FII-40) used in the examples are shown.
Tables 1 and 2 below show the weight average molecular weights and the like of the fluorine group-containing resins (FII-1) to (FII-40).

Examples 1 to 25 and Comparative Example 1
<Resist preparation>
The components shown in Table 3 below were dissolved in a solvent to prepare a solution having a solid concentration of 12% by mass, and this was filtered through a 0.1 μm polytetrafluoroethylene filter or a polyethylene filter to prepare a positive resist solution. The prepared positive resist solution was evaluated by the following method, and the results are shown in Table 3.

<Resist evaluation>
First, ARC-29A-8 manufactured by Brewer Science was applied to a silicon wafer at 78 nm using a spin coater and dried, and then the obtained positive resist solution was applied thereon and dried at 120 ° C. for 60 seconds. A 200 nm positive resist film was prepared, and exposed to an ArF excimer laser (ArF stepper manufactured by ISI having a wavelength of 193 nm and NA = 0.6), and immediately after the exposure, heating was performed at 115 ° C. for 90 seconds. Development with a mass% tetramethylammonium hydroxide aqueous solution and rinsing with distilled water gave a resist pattern profile.

The resist pattern of the silicon wafer thus obtained was observed with an SEM, and the resist was evaluated as follows.
<Sensitivity / exposure latitude>
An exposure amount that reproduces a line-and-space mask pattern with a line width of 0.13 μm is an optimum exposure amount (sensitivity), and an exposure amount width that allows a pattern size of 0.13 μm ± 10% when the exposure amount is changed. This value was divided by the optimum exposure amount and displayed as a percentage. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude.

<Resolution and profile of contact holes>
The resolving power was defined as the limiting resolving power at an exposure amount that reproduces an isolated contact hole with a mask size of 180 nm at 130 nm. Further, the profile of the contact hole pattern of 130 nm was observed with a cross-sectional SEM.

Hereinafter, the abbreviations in each table are as follows. Resins and acid generators other than those listed below are those exemplified above. In each table, the ratio when a plurality of resins or solvents are used is a mass ratio.
[Acid generator]

[Basic compounds]
DBN; 1,5-diazabicyclo [4.3.0] non-5-ene TPI; 2,4,5-triphenylimidazole TPSA; triphenylsulfonium acetate HEP; N-hydroxyethylpiperidine DIA; 2,6-diisopropyl Aniline DCMA; Dicyclohexylmethylamine TPA; Tripentylamine TOA; Tri-n-octylamine HAP; Hydroxyantipyrine TBAH; Tetrabutylammonium hydroxide TMEA; Tris (methoxyethoxyethyl) amine PEA; N-phenyldiethanolamine

[Surfactant]
W-1; Megafac F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2; Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4; Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

〔solvent〕
A1; propylene glycol methyl ether acetate A2; 2-heptanone A3; ethyl ethoxypropionate A4; γ-butyrolactone A5; cyclohexanone B1; propylene glycol methyl ether B2;

[Dissolution inhibitor]
LCB; t-butyl lithocholic acid

  From Table 3, it can be seen that the positive resist compositions of Examples 1 to 25 have a good balance of sensitivity, exposure latitude, resolution, and profile.

Examples 26 to 28 and Comparative Example 2
<Formation of lower resist layer>
A 6-inch silicon wafer was coated with FHi-028DD resist (resist for i-line manufactured by Fuji Film Orin) using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 90 ° C. for 90 seconds to form a uniform film having a thickness of 0.55 μm. Obtained.
This was further heated at 200 ° C. for 3 minutes to form a lower resist layer having a thickness of 0.40 μm.

<Formation of upper resist layer>
The components shown in the following Table 4 were dissolved in a solvent to prepare a solution having a solid content concentration of 11% by mass, and subjected to microfiltration with a membrane filter having a diameter of 0.1 μm to prepare an upper resist composition.
The upper resist composition was similarly applied onto the lower resist layer and heated at 130 ° C. for 90 seconds to form an upper resist layer having a thickness of 0.20 μm.

<Performance evaluation>
The wafer thus obtained was exposed with an ArF excimer laser (ArF stepper manufactured by ISI having a wavelength of 193 nm and NA = 0.6). Subsequently, after heating at 120 ° C. for 90 seconds, the film was developed with a tetrahydroammonium hydroxide developer (2.38 mass%) for 60 seconds, rinsed with distilled water, and dried to obtain an upper layer pattern.
The resist pattern of the silicon wafer thus obtained was observed with an SEM and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

  Resins (SI-1) to (SI-3) in Table 4 are as follows.

  From Table 4, it is clear that the positive resist compositions of Examples 26 to 28 have small PEB temperature dependency and improved contact hole resolution and profile.

Examples 29 to 48 and Comparative Example 3
<Resist preparation>
The components shown in Table 5 below were dissolved in a solvent and filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a positive resist solution.

<Resist evaluation>
Each positive resist solution was applied to a silicon wafer subjected to hexamethyldisilazane treatment by a spin coater and dried by heating on a vacuum contact hot plate at 120 ° C. for 90 seconds to obtain a resist film having a thickness of 100 nm.
The obtained resist film was exposed using a 157 nm laser exposure / dissolution behavior analyzer VUVES-4500 (manufactured by RISOTEC Japan), and immediately after the exposure, it was heated on a hot plate at 120 ° C. for 90 seconds. The sample was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds and rinsed with pure water to obtain a sample wafer. For these, the exposure amount (sensitivity) at which the large pattern was resolved was determined.

  From Table 5, it was found that the positive resist compositions of Examples 29 to 33 exhibited contrast even in exposure at a wavelength of 157 nm.

In the above examples, ArF excimer laser light and F ₂ excimer laser light are used as actinic rays, but similar results were obtained in the case of exposure with KrF excimer laser light and electron beams.
Further, the positive resist composition of the present invention is considered to exhibit the same effect with respect to EUV light.

Claims (5)

A positive resist composition containing a compound represented by the general formula (S).

In general formula (S),
Ar represents an aryl group.
R ₁ and R ₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. R ₁ and R ₂ may combine to form a ring.
Y ₁ and Y ₂ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. Y ₁ and Y ₂ may combine to form a ring.
X ⁻ represents one of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring. The positive resist composition according to claim 1, wherein the compound represented by the general formula (S) is a compound represented by the general formula (S-1).

In general formula (S-1),
Ar represents an aryl group.
R _1a and R _2a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and at least one of them is not a hydrogen atom. R _1a and R _2a may combine to form a ring.
Y ₁ and Y ₂ each independently represents an alkyl group, a cycloalkyl group, or an aryl group. Y ₁ and Y ₂ may combine to form a ring.
X ⁻ represents one of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring. The positive resist composition according to claim 1, wherein the compound represented by the general formula (S) is a compound represented by the general formula (S-2).

In general formula (S-2),
Ar represents an aryl group.
R _1a and R _2a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and at least one of them is not a hydrogen atom. R _1a and R _2a may combine to form a ring.
Y _1b and Y _2b each independently represent an alkyl group, a cycloalkyl group, or an aryl group. Y _1b and Y _2b are not bonded to form a ring.
X ⁻ represents one of the following anions.

In the formulas (A1) to (A2),
R _{a1 to} R _a5 each independently represents an aliphatic hydrocarbon group. R _a1 and R _a2 may be bonded to each other to form a ring, and two of R _{a3 to} R _a5 may be bonded to each other to form a ring. Furthermore, the positive resist composition in any one of Claims 1-3 containing the acid-decomposable resin containing the following monomer unit.

In formula (P1),
R ^p1 represents a hydrogen atom or an alkyl group.
R ^p2 , R ^p3 and R ^p4 each independently represents a hydrogen atom or a hydroxyl group, and at least one of R ^p2 , R ^p3 and R ^p4 represents a hydroxyl group.   A pattern forming method comprising: forming a resist film from the positive resist composition according to claim 1; and exposing and developing the resist film.