JP2005234451A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition which solves problems in a technique for improving the original performance of microphotofabrication using far ultraviolet light, particularly ArF excimer laser light, and to specifically provide a positive resist composition excellent in various properties such as PEB temperature dependency, exposure margin and profile, and a pattern forming method using the same. <P>SOLUTION: The positive resist composition contains a resin containing a specified (meth)acrylic ester repeating unit and having velocity of dissolution in an alkaline developer increased by the action of an acid, and a compound which generates an acid upon irradiation with active light or radiation. The pattern forming method uses the same. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a positive photoresist composition for microfabrication of semiconductor elements and the like that is sensitive to deep ultraviolet rays, and more particularly to a positive photoresist composition for deep ultraviolet exposure.

  In recent years, the degree of integration of integrated circuits has been increasing, and in the manufacture of semiconductor substrates such as VLSI, processing of ultra-fine patterns having a line width of less than half a micron has been required. In order to satisfy this need, the wavelength used by exposure apparatuses used in photolithography has become increasingly shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. It is becoming.

  A chemical amplification type resist is used for lithography pattern formation in this wavelength region.

  As a photoresist composition for an ArF light source, a resin into which an alicyclic hydrocarbon moiety is introduced has been proposed for the purpose of achieving both transparency at an exposure wavelength and imparting dry etching resistance. As such a resin, a monomer having a carboxylic acid site such as acrylic acid or methacrylic acid or a monomer having a hydroxyl group or a cyano group in the molecule is copolymerized with a monomer having an alicyclic hydrocarbon group. Resin.

  On the other hand, in addition to the method of introducing an alicyclic hydrocarbon moiety into the side chain of the acrylate monomer, a method of imparting dry etching resistance utilizing an alicyclic hydrocarbon moiety as a polymer main chain has been studied.

Traditionally, in photoresist compositions used for KrF light sources, etc., a phenolic hydroxyl group was used as an alkali-soluble group, and a resin protected with an acetal protecting group could be used, so high deprotection was easily realized. I was able to do it. In ArF light sources, phenolic hydroxyl groups are extremely disadvantageous in terms of exposure wavelength transmission, and many researchers have been working on the development of alternative systems.
Patent Document 1 (Japanese Patent Application Laid-Open No. 9-73173) includes an alkali-soluble group protected with a structure containing an alicyclic group and a structural unit that makes the alkali-soluble group detached by an acid to make it alkali-soluble. A resist material using an acid sensitive compound is described. The resist disclosed here is an excellent system with improved dry etching resistance without deteriorating the exposure wavelength transmittance, but various problems remain due to the low reactivity of the protective group.

  On the other hand, Patent Document 2 (Japanese Patent Application Laid-Open No. 10-161313) improves the developer wettability by improving the structure of the protective group containing an alicyclic group and improving the detachability, thereby increasing the sensitivity.・ Expanded exposure margin.

  Moreover, in patent document 3 (Unexamined-Japanese-Patent No. 2000-336121), by using the substituted norbornane ester which has a specific three-dimensional structure as a protective group, deprotection property is improved and the sensitivity and the resolution are achieved. However, in these systems, various problems due to the reactivity of the protecting group still remain, and there remains room for further improvement.

  On the other hand, in Patent Document 4 (Japanese Patent Laid-Open No. 3-192173), it has been proposed that both high sensitivity and constant stability over time can be achieved by using a resin having an acetal ester structure as a protecting group. The problem is that it is difficult to obtain a sufficient resolving power in a fine pattern region such as several hundreds to several tens of nanometers required for an ArF system.

  In general, the resin containing an acid-decomposable group used for the photoresist for exposure to far ultraviolet rays as described above contains an aliphatic cyclic hydrocarbon group in the molecule at the same time. The above techniques are still inadequate and various improvements are desired.

For example, when a wafer having a large diameter is used, it has been found that temperature variations in heating (PEB) using a hot plate after exposure affect the obtained pattern. Smallness has been desired. In addition, it is desired that exposure margins and process margins be wide because they are less susceptible to variations in exposure conditions. The exposure margin refers to a characteristic in which the obtained line width is not easily affected by fluctuations in the exposure amount, and the process margin refers to a characteristic difficult to be affected by fluctuations in the exposure amount and the focal position.
JP-A-9-73173 JP-A-10-161313 JP 2000-336121 A Japanese Patent Laid-Open No. 3-192173

  Accordingly, an object of the present invention is to provide a positive resist composition that solves the problems in the technology for improving the original performance of microphotofabrication using far ultraviolet light, particularly ArF excimer laser light. More specifically, an object is to provide a positive resist composition excellent in various performances such as PEB temperature dependency and exposure margin without deteriorating sensitivity, pattern profile and the like.

As a result of intensive studies on the constituent materials of the positive resist composition, the present inventors have found that the object of the present invention can be achieved by the following constitution, and have reached the present invention.
[1] (A) A resin containing a repeating unit represented by the following general formula (1), which increases the dissolution rate in an alkali developer by the action of an acid, and (B) an acid by irradiation with actinic rays or radiation. A positive resist composition containing a generated compound.

In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² represents a monovalent organic group, and L ¹ represents a divalent linking group.
[2] A pattern forming method comprising: forming a resist film from the positive resist composition according to [1]; and exposing and developing the resist film.

  According to the present invention, a positive resist composition excellent in various performances such as PEB temperature dependency can be provided.

Hereinafter, the components used in the present invention will be described in detail.
In addition, in the description of a group (atomic group) in this specification, the description which does not describe substituted and unsubstituted includes what has a substituent with what does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
[1] Resin that increases the dissolution rate in an alkaline developer by the action of an acid (component A)
The resin (acid-decomposable resin), which is contained in the resist composition of the present invention and has an increased dissolution rate in an alkaline developer by the action of an acid, contains a repeating unit represented by the general formula (1).

In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² represents a monovalent organic group, and L ¹ represents a divalent linking group.

The alkyl group in R ¹ in the general formula (1) may be substituted and preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a hydroxymethyl group, an acetoxymethyl group, and the like. Can do. R ¹ is preferably a hydrogen atom or a methyl group, and most preferably a methyl group.

The monovalent organic group as R ² preferably has 1 to 40 carbon atoms, and is preferably an alkyl group or a cycloalkyl group.

The alkyl group as R ² may have a substituent, and is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. Branched alkyl group, more preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl Group, nonyl group and decyl group.

The cycloalkyl group for R ² may be monocyclic or polycyclic, and may have a substituent. For example, groups having a monocyclo, bicyclo, tricyclo or tetracyclo structure having 5 or more carbon atoms can be given. The carbon number is preferably 6-30, and particularly preferably 7-25.

  Preferred examples of the cycloalkyl 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, a cyclooctyl group, and a cyclodecanyl group. And cyclododecanyl group. More preferable examples include 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 that the alkyl group and cycloalkyl group may have include, for example, a hydroxyl group, a carboxy group, a cyano group, a halogen atom (for example, a chlorine atom, a bromine atom, a fluorine atom, an iodine atom), an alkoxy group ( Preferably it has 1 to 4 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, etc., acyl group (preferably 2 to 5 carbon atoms, such as formyl group, acetyl group, etc.), acyloxy group (preferably carbon Examples thereof include 2 to 5, for example, an acetoxy group, an aryl group (preferably 6 to 14 carbon atoms, for example, a phenyl group), a cycloalkyl group (for example, a cycloalkyl group as R ² ), and the like.

Regarding the cyclic structure possessed by the above substituent, examples of the substituent further include an alkyl group (for example, an alkyl group as R ² ).

Examples of the divalent linking group of L ¹ include a divalent linking group formed by arbitrarily bonding the bonds of the following linking block or two or more linking blocks.

  As a connection block, the following (L-1)-(L-23) can be mentioned, for example.

In the following formulae, R ^L each independently represents a halogen atom, a hydroxyl group, a mercapto group, a monovalent organic group, or a single bond bonded to any atom constituting a linking group. Z ⁻ is not particularly limited as long as it is an anion corresponding to a conjugate base of an organic acid and an inorganic acid, and may be a polyvalent anion. These anions include R ^a1 —SO ₃ ⁻ , R ^a1 —SO ₂ ⁻ , R ^a1 —CO ₂ ⁻ , R ^a1 —CS ₂ ⁻ , R ^a1 —O—CS ₂ ⁻ , R ^a1 —S—CS _{2. ^{-, R a1 -O-PO 2}} -, (R a1 -O) 2 PO 2 -, R a1 (R a1 -O) PO 2 -, R a1 -EW 1 -Z - -EW 2 -R a1, ( R ^a1 ) Anions corresponding to organic acid conjugate bases such as B ⁻ , Ar ^x O ⁻ , or F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , SbF ₆ ⁻ , ClO _{4 ^{-, SO 4 2-, NO 3}} -, CO 3 2-, SCN -, CN -, SiF 6 -, FSO 3 -, 3 -, Br 3 -, IBr 2 -, corresponding to inorganic acids conjugate base of an equal And anions. Here, R is an organic substituent, and represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, or a group further substituted therewith, and when there are a plurality of them in the molecule, they are selected independently from each other. They may be combined with each other to form a ring. EW ¹ and EW ²⁻ represent an electron-withdrawing group, and specific examples include —SO—, —CO—, —SO ₂ —, —CN and the like. Z represents —CR ^z1 — or ^—N— (R ^z1 represents a hydrogen atom or a substituent). Ar ^x represents an aryl group.

L ¹ is preferably a linking group having at least one block of (L-6), more preferably a linking group having at least one block of (L-4) and (L-6). More preferably a linking group having at least one block of (L-1), (L-4) and (L-6), most preferably (L-1), (L-4). ) And (L-6) each having at least one block, and the total number of blocks constituting the linking group is 4 or more (preferably 4 to 20).

  In general formula (1), the structure of the following general formula (1-A) can be mentioned as a preferable form.

In the general formula (1-A), R ¹ and R ² have the same meanings as those in the general formula (1), and preferred ranges thereof are also the same. L ² represents the same divalent linking group as L ¹ in the general formula (1). X represents a linking group selected from —O—, —S—, —NR ^X — (R ^X represents a hydrogen atom, an alkyl group, or an aryl group).

The divalent organic group as L ² used in the present invention is preferably a linking group having at least one block of (L-4), more preferably two or more blocks of (L-4). (More preferably (L-4) is a linking group having 2 to 18 blocks) and a linking group having at least one ring structure formed by bonding a plurality of R ^L to each other, most preferably , (L-4) is a linking group having three or more blocks and having at least one ring structure formed by bonding a plurality of R ^L to each other.

X is preferably selected from —O—, —S—, —NR ^X — (R ^X represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms). Represents a linking group, more preferably —O—, —NR ^X —, and most preferably —O—.

  Although the suitable example of the repeating unit represented by General formula (1) is given below, it is not limited to these.

The monomer corresponding to the repeating unit represented by the general formula (1) can be synthesized by reacting R ² —O—CH ₂ —X with a carboxylic acid having a polymerizable group in the presence of a base. . Here, X represents a leaving group represented by a halogen atom such as Cl or —OR ^2a (R ^2a is an alkyl group, an aryl group, a hydrogen atom, etc.). It can also be obtained by a method such as acetal exchange.

  The resin of the present invention is a resin (acid-decomposable resin) that is decomposed by the action of an acid and increases the solubility in an alkaline developer, and is either the main chain or side chain of the resin, or both the main chain and side chain And a resin having a group (hereinafter also referred to as an “acid-decomposable group”) that is decomposed by an acid and becomes alkali-soluble.

  In addition to the repeating unit represented by the general formula (1) in the present invention, the resin of the present invention may have a repeating unit having a group that decomposes by the action of an acid.

Examples of the group capable of decomposing by the action of an acid include groups represented by —COOA ⁰ and —O—B ⁰ groups. Examples of the group containing these include a group represented by —R ⁰ —COOA ⁰ or —Ar—O—B ⁰ .

Here, A ⁰ is -C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -Si (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -C (R ⁰⁴ ) (R ⁰⁵ ) -O-R ⁰⁶ group or lactone group. B ⁰ represents —A ⁰ or —CO—O—A ⁰ group.

^{R 01, R 02, R 03} , R 04 and R ⁰⁵ may also be different from, and each of the same, represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group, R ⁰⁶ Represents an alkyl group, a cycloalkyl group or an aryl group. However, at least two of R ^{01 to} R ⁰³ are groups other than hydrogen atoms, and two groups of R ^{01 to} R ⁰³ and R ^{04 to} R ⁰⁶ are bonded to form a ring. Also good.

R ⁰ represents a single bond or a divalent or higher aliphatic or aromatic hydrocarbon group, and —Ar— represents a divalent or higher aromatic group which may have a monocyclic or polycyclic substituent. .

  Here, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, or a t-butyl group. Those having 3 to 30 carbon atoms such as propyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferred, and the alkenyl group has 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Those having 6 to 14 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl, and anthracenyl groups are preferable. Examples of the cycloalkyl group include those having 3 to 30 carbon atoms, specifically, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group, tricyclodecanyl group, dicyclo group. Examples thereof include a pentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a tetracyclododecanyl group, and a steroid residue. Examples of the aralkyl group include those having 7 to 20 carbon atoms, such as a benzyl group, a phenethyl group, and a cumyl group.

  Each of the above groups may have a substituent, such as a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the above alkyl group, a methoxy group, an ethoxy group, Hydroxyethoxy group, propoxy group, hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as t-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, benzyl group, phenethyl Group, aralkyl group such as cumyl group, aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanamyl group, acyl group such as valeryl group, acyloxy group such as butyryloxy group, the above alkenyl group, vinyloxy group, Propenyloxy, allyloxy, butenyloxy, etc. Keniruokishi group, said aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group.

  Examples of the lactone group include those having the following structure.

In the above formula, R ^a , R ^b and R ^c each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n represents an integer of 2 to 4.

When an ArF excimer laser is used as a light source for exposure, it is preferable to use a group represented by —C (═O) —X ₁ —R ₀ as a group that is decomposed by the action of an acid. Here, as R ₀ , tertiary alkyl groups such as t-butyl group and 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, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl group, 3-oxocyclohexyl group, the above lactone group Etc. X ₁ represents an oxygen atom or a sulfur atom, preferably an oxygen atom.

  In the acid-decomposable resin used in the present invention, the content of the repeating unit represented by the general formula (1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol% in all repeating units. More preferably, it is 15-40 mol%.

  The content of the repeating unit having an acid-decomposable group is preferably from 25 to 70 mol%, more preferably from 27 to 60 mol%, still more preferably from 29 to 50 mol% in all repeating structural units.

  When the composition of the present invention is irradiated with ArF excimer laser light, the resin of component (A) has a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposes by the action of an acid, and an alkaline developer. It is preferable that it is resin (henceforth an "alicyclic ring-containing acid-decomposable resin") whose solubility with respect to the resin increases. As such a resin, together with the repeating unit represented by the general formula (1), the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI), and the following A resin containing at least one selected from the group of repeating units represented by formula (II-AB) is preferred.

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.

R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R _{12 to} R ₁₄ , 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 Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group.

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 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 represents a hydrogen atom, a cyano group, a halogen atom, or an alkyl group.

  Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  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.

Wherein, R ₅ represents an alkyl group, cyclic hydrocarbon group, or -Y group shown below.

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 ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group.

R ₆ represents an alkyl group or a cyclic hydrocarbon group.

  The -Y group;

In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an 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 (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

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

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

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

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

  The structures represented by the general formulas (pI) to (pVI) can be used for protecting an alkali-soluble group, that is, can constitute an acid-decomposable group. 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.

  Preferred examples of the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the resin include groups represented by the following general formulas (pVII) to (pXI).

Here, R _{11 to} R ₂₅ and Z are the same as defined above.

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

  Here, R represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.

  A is a single bond, a group selected from the group consisting of an 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, or a combination of two or more groups. Represents.

  Ra represents any group of the above formulas (pI) to (pVI).

  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.

  Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

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.

The alkyl group in R ₁₁ ′, R ₁₂ ′, and R ₂₁ ′ to R ₃₀ ′ 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 further substituent in the above alkyl group include a hydroxyl group, a halogen atom, a carboxy 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 alicyclic hydrocarbon skeleton formed include R _{11 to} R _{25 in} the general formulas (pI) to (pVI) and the alicyclic portion of Z ′ in the general formula (II-AB). Examples similar to the structural examples (1) to (51) may be mentioned.

  As a preferable bridged alicyclic hydrocarbon skeleton, among the structural examples, (5), (6), (7), (9), (10), (13), (14), ( 15), (23), (28), (36), (37), (42), (47).

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 acid-decomposable resin according to the present invention, the acid-decomposable group may be contained in the aforementioned —C (═O) —XA′—R ₁₇ ′ or represented by the general formula (II-AB). May be included as a substituent for Z ′.

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 and R ₁₃ ′ to R ₁₆ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear chain having 1 to 6 carbon atoms. Or a 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 carboxy 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 thereof 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.

  Examples of the alkylene group for A ′ include groups represented by the following formulae.

− [C (R _a ) (R _b )] _r −
In the formula, R _a and R _b represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and both may be the same or different. 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 selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. These groups may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group or the like. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r represents an integer of 1 to 10.

  In the alicyclic-containing acid-decomposable resin according to the present invention, the group that decomposes by the action of an acid is a repeating structure having a partial structure containing an 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 unit, 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 acid-decomposable resin of the present invention preferably has a lactone group, more preferably represented by any one of the following general formula (Lc) or the following general formulas (V-1) to (V-5). It has a repeating unit having a group having a lactone structure, 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. 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, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group. Represents. 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.

  The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. More preferably, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl It is a group.

As a cycloalkyl group in R _<1b > -R < _5b >, C3-C8 things, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, are preferable.

As an alkenyl group in R _<1b > -R < _5b >, C2-C6 things, such as a vinyl group, a propenyl group, a butenyl group, a hexenyl group, are preferable.

Examples of the ring formed by combining two of R _{1b to} R _5b include 3- to 8-membered rings such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring.

In the general formulas (V-1) to (V-5), R _{1b to} R _5b may be connected to any carbon atom constituting the cyclic skeleton.

Preferred substituents that the alkyl group of Ra _{1 to} Re ₁ and the alkyl group, cycloalkyl group, alkoxy group, alkoxycarbonyl group, alkylsulfonylimino group, and alkenyl group of R _{1b to} R _5b may have include 1 to 4 alkoxy groups, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, A C2-C5 alkoxycarbonyl group, a nitro group, etc. can be mentioned.

As the repeating unit having a group having a lactone structure represented by general formula (Lc) or any one of 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 an 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 _b represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.

V represents a group represented by any one of the general formula (Lc) and the general formulas (V-1) to (V-5). In A _b, examples of the divalent group formed by combining the above divalent group include for example those of the following formulas.

In the above formula, R _ab and R _bb represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and both may be the same or different.

  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 selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent for the alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms.

  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 halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r1 represents an integer of 1 to 10, preferably an integer of 1 to 4. m represents an integer of 1 to 3, preferably 1 or 2.

  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 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 _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c 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 in} —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 _1c represents a hydrogen atom or a methyl group, and is particularly preferably a methyl group.

R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

  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 acid-decomposable resin 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. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

The alkyl group in R ₄₁ and R ₄₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. More preferred are methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and t-butyl group.

Examples of the substituted alkyl group in R ₄₁ and R ₄₂ include haloalkyl groups such as a trifluoromethyl group, nanofluorobutyl group, pentadecafluorooctyl group, and trichloromethyl group. Examples of the cycloalkyl group for R ₄₂ include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

The alkyl group as R ₄₁ and R ₄₂ , the cycloalkyl group as R ₄₂ , or the camphor residue may have a substituent. Examples of such a substituent include a hydroxyl group, a carboxy group, a cyano group, a halogen atom (for example, a chlorine atom, a bromine atom, a fluorine atom, an iodine atom), an alkoxy group (preferably having 1 to 4 carbon atoms, for example, methoxy Group, ethoxy group, propoxy group, butoxy group, etc.), acyl group (preferably having 2 to 5 carbon atoms, such as formyl group, acetyl group, etc.), acyloxy group (preferably having 2 to 5 carbon atoms, such as acetoxy group), An aryl group (preferably having 6 to 14 carbon atoms, for example, a phenyl group) and the like can be mentioned.

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

  In addition to the above repeating structural units, the alicyclic-containing acid-decomposable resin has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power, heat resistance, and sensitivity. Various repeating structural units can be contained for the purpose of adjusting the above.

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

Thereby, performance required for the alicyclic 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 the alicyclic-containing acid-decomposable resin, the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and the general required performance of resist, resolution and heat resistance. It is appropriately set to adjust the property, sensitivity, etc.

  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 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 usually 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 50 to 100 ° C.

In the positive resist composition of the present invention, the blending amount of all resins according to the present invention in the entire composition is preferably 40 to 99.99% by mass, more preferably 50 to 99.97, based on the total solid content of the resist. % By mass.
[2] Compound that generates acid upon irradiation with actinic rays or radiation (component B)
As a compound (acid generator) that generates an acid upon irradiation with actinic rays or radiation, a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, or a micro Known compounds that generate an acid upon irradiation with actinic rays or radiation used for resists 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.

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

In the above general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.

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

Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.

The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).

X ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion as X ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion having a remarkably low ability to cause a nucleophilic reaction, and is an anion capable of suppressing degradation with time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an alkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

  The alkyl moiety in the alkyl sulfonate anion may be an alkyl group or a cycloalkyl group, and preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, such as a methyl group or an ethyl group. Group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group Tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.

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

  The alkyl group, cycloalkyl group, and aryl group in the alkyl sulfonate anion and aryl sulfonate anion may have a substituent.

  Examples of such substituents include nitro groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxy groups, hydroxyl groups, amino groups, cyano groups, and alkoxy groups (preferably having 1 to 5 carbon atoms). ), A cycloalkyl group (preferably 3 to 15 carbon atoms), an aryl group (preferably 6 to 14 carbon atoms), an alkoxycarbonyl group (preferably 2 to 7 carbon atoms), an acyl group (preferably 2 to 12 carbon atoms). ), An alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the alkyl moiety in the alkylcarboxylate anion include those similar to the alkyl group and cycloalkyl group in the alkylsulfonate anion.

  Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate anion.

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

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent include an arylsulfonate anion. And the same halogen atom, alkyl group, cycloalkyl group, alkoxy group, alkylthio group and the like as in.

  Examples of the sulfonylimide anion include saccharin anion.

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

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

As the non-nucleophilic anion of X ⁻ , an alkanesulfonic acid anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an arylsulfonic acid anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group having a fluorine atom And a tris (alkylsulfonyl) methide anion in which the alkyl group is substituted with a fluorine atom. The non-nucleophilic anion is particularly preferably a perfluoroalkanesulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, most preferably nonafluorobutanesulfonic acid anion, perfluorooctanesulfonic acid anion, penta Fluorobenzenesulfonate anion, 3,5-bis (trifluoromethyl) benzenesulfonate anion.

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

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

  More preferable (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

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

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 with the remaining being an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, and an aryldialkylsulfonium compound.

  The aryl group of the arylsulfonium compound is preferably 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 or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

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

  Next, the compound (ZI-2) will be described.

Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group containing no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

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

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, most preferably a linear or branched 2-oxoalkyl group.

As the alkyl group and cycloalkyl group represented by R _{201 to} R ₂₀₃ , a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group.

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

  The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

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

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

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

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

R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.

R _6c and R _7c represent a hydrogen atom, an alkyl group, or a cycloalkyl group.

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

Any two or more of R _{1c to} R _5c , 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, and examples thereof include the same as the non-nucleophilic anion of X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _{5c 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 ( For example, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group)
Examples of the cycloalkyl group include a cyclic alkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).

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

Preferably, any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _1c to R _5c is 2 to 2. 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group and cycloalkyl group as R _x and R _y include the same alkyl groups and cycloalkyl groups as R _{1c to} R _{5c, such} as a 2-oxoalkyl group and a 2-oxocycloalkyl group. An alkoxycarbonylmethyl group is more preferable.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _5c .

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

Examples of the group formed by combining R _x and R _y include a butylene group and a pentylene group.

R _x and R _y are preferably an alkyl group 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.

Alkyl group and cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon A cyclic alkyl group (cyclopentyl group, cyclohexyl group, norbornyl group) of several 3 to 10 can be exemplified.

The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate acids, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

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

  In addition, as a compound that decomposes upon irradiation with active light or radiation to generate an acid, a compound that generates a sulfonic acid having one sulfonic acid group is preferable, and a compound that generates a monovalent perfluoroalkanesulfonic acid is more preferable. Or a compound that generates an aromatic sulfonic acid substituted with a fluorine atom or a group containing a fluorine atom.

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

The amount of component (B) added is generally 0.05 to 20% by mass, preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the resist composition. is there.
[3] Fluorine-based and / or silicon-based surfactant The positive resist composition of the present invention includes any of a fluorine-based surfactant, a silicon-based surfactant, and a surfactant containing both fluorine atoms and silicon atoms. Or it is preferable to contain 2 or more types.

  When the positive resist composition of the present invention contains the acid-decomposable resin and the surfactant, it is particularly effective when the line width of the pattern is narrower and development defects are further improved.

  As these fluorine-based and / or silicon-based surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950 are disclosed. JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A-2002-277862, US Pat. 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 The following commercially available surfactants can also be used as they are.

  Examples of commercially available fluorine-based and / or silicon-based 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.), Megafac 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) Fluorine-based surfactants or silicon-based surfactants such as those manufactured by K.K. 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 shown above, fluorine-based and / or silicon-based surfactants can be produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method). A surfactant using a polymer having a fluoroaliphatic group derived from a fluoroaliphatic compound 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).

For example, as a commercially available fluorine-based and / or silicon-based surfactant, Megafac F178, F-470, F-473, F-475, F-476, F-472 (manufactured by Dainippon Ink & Chemicals, Inc.) Can be mentioned. 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 the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, and particularly preferably 0.01 to the total amount of the positive resist composition (excluding the solvent). It is mass%-1 mass%.
[4] Organic Basic Compound The positive resist composition of the present invention preferably contains an organic basic compound. A preferable organic basic compound is a compound having a stronger basicity than phenol. Of these, nitrogen-containing basic compounds are preferable, and examples thereof include structures represented by the following (A) to (E).

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

In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group or a cycloalkyl 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 imidazole, substituted or unsubstituted 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 amino Examples include morpholine and substituted or unsubstituted aminoalkylmorpholine. Preferred substituents are amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group It is.

  Preferable specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethyl. Aminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2 -Amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino -2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-i Nopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5 Methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-diazabicyclo [ 4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] octane, 2,4,5- Triphenylimidazole, N-methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohex Examples include tertiary morpholine derivatives such as lumorpholinoethylthiourea (CHMETU), hindered amines described in JP-A-11-52575 (for example, those described in the publication [0005]), and the like, but are not limited thereto. Absent.

  Particularly preferred examples are 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2. 2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, tertiary morpholines such as CHMETU, bis (1, 2,2,6,6-pentamethyl-4-piperidyl) sebagate and other hindered amines, N, N-dihydroxyethylaniline, N, N-dibutylaniline, trioctylamine, triphenylimidazole, antipyrine, 2,6-diisopropyl And aniline.

  Among them, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, CHMETU, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate, N, N-dihydroxyethylaniline, N, N-dibutylaniline, tri Octylamine, triphenylimidazole, antipyrine, and 2,6-diisopropylaniline are preferred.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The usage-amount of a nitrogen-containing basic compound is 0.001-10 mass% normally with respect to solid content of the whole composition of the resist composition of this invention, Preferably it is 0.01-5 mass%. That is, 0.001% by mass or more is preferable from the viewpoint of obtaining a sufficient addition effect, and 10% by mass or less is preferable from the viewpoint of sensitivity and developability of the non-exposed area.
[5] Solvent The composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethylene carbonate, toluene, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, pyruvin Ethyl acetate, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl Pyrrolidone, tetrahydrofuran and the like are preferable to use these solvents singly or in combination.

Among these, preferable solvents include propylene glycol monomethyl ether acetate, 2-heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether , Ethylene carbonate, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, N-methylpyrrolidone and tetrahydrofuran.
[6] Other Additives The composition of the present invention further has solubility in other surfactants, acid-decomposable dissolution inhibiting compounds, dyes, plasticizers, photosensitizers, and developers as necessary. A compound to be promoted and the like can be contained.

Specific examples of the other surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, and polyoxyethylene. Polyoxyethylene alkyl allyl ethers such as octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan Sorbitan fatty acid esters such as trioleate, sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polio Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as ciethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, etc. be able to.
[7] Preparation of composition The resist composition prepared by dissolving each component in a solvent is preferably 3 to 25% by mass, and 5 to 22% by mass as the total solid content. More preferably, the content is 7 to 20% by mass.

  Such a positive resist composition of the present invention is applied onto a substrate to form a thin film. The thickness of this coating film is preferably 0.2 to 1.2 μm.

  Examples of the substrate that can be used include a normal BareSi substrate, an SOG substrate, and a substrate having an inorganic antireflection film described below.

  If necessary, a commercially available inorganic or organic antireflection film can be used.

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

  Further, as the organic antireflection film, DUV30 series, DUV-40 series, ARC25, AC-2, AC-3, AR19, AR20, etc., manufactured by Brewer Science can be used.

Appropriate use of the resist solution on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements (if necessary on the substrate provided with the antireflection film), spinner, coater, etc. A good resist pattern can be obtained by coating with an appropriate coating method, forming a resist film, exposing with actinic rays or radiation through a predetermined mask, baking and developing. Here, the actinic ray or radiation is preferably light having a wavelength of 150 nm to 250 nm. Specific examples include a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), an F ₂ excimer laser (157 nm), an X-ray, and an electron beam.

  Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di- Secondary amines such as n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions (usually 0.1 to 10% by mass) of cyclic amines such as salts, pyrrole and pihelidine can be used.

  Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.
Synthesis Example (1) Synthesis of Resin (1) Monomers (A1), (B1) and (C1) having the following structure were charged at a ratio of 30/40/30, and PGMEA (propylene glycol monomethyl ether acetate) / PGME (propylene glycol) Monomethyl ether) = 7/3 (mass ratio) was dissolved to prepare 450 g of a solution having a solid concentration of 22% by mass. 1 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was heated to 100 ° C. for 6 hours under a nitrogen atmosphere. PGMEA (propylene glycol monomethyl ether acetate) / PGME (propylene glycol monomethyl ether) = 7 / The solution was added dropwise to 50 g of a 3 (mass ratio) mixed solution. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (1).

  The polymer composition ratio determined from NMR was 29/40/31. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 8600.

  Resins (2) to (16) were synthesized by the same operation as in the above synthesis example. Resins (15) and (16) are comparative resins.

Examples 1 to 24 and Comparative Examples 1 and 2
(Preparation and evaluation of positive resist composition)
As in Table 2,
Resin synthesized in the above synthesis example (2 g),
Photoacid generator (blending amount shown in Table 2),
Organic basic compound (4 mg),
Surfactant (10mg)
And dissolved in the solvents shown in Table 2 so that the solid content is 10% by mass, then filtered through a 0.1 μm microfilter, and further filtered through a 0.03 μm filter. Examples 1 to 24 and comparison The positive resist compositions of Examples 1 and 2 were prepared. In addition, the ratio at the time of using two or more about each component in Table 2 is a mass ratio.

The symbol of each component in Table 2 shows the following.
[Surfactant]
1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine and silicone)
3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
4: Polyoxyethylene nonylphenyl ether 5: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
[Basic compounds]
1: N, N-dihydroxyethylaniline 2: N, N-dibutylaniline 3: trioctylamine 4: triphenylimidazole 5: antipyrine 6: 2,6-diisopropylaniline 7: 1,5-diazabicyclo [4.3. 0] -5-Nonene (DBN)
〔solvent〕
S1: Propylene glycol monomethyl ether acetate S2: Propylene glycol monomethyl ether S3: γ-butyrolactone S4: Cyclohexanone S5: Ethyl lactate S6: Butyl acetate [Evaluation method]
(Pattern profile)
The positive photoresist solution prepared above is applied onto a silicon wafer using a spin coater and dried at the temperature (SB) shown in Table 2 for 90 seconds to produce a positive photoresist film of about 0.3 μm. Then, it was exposed with an ArF excimer laser (ArF stepper manufactured by ISI having a wavelength of 193 nm and NA = 0.6). The heat treatment after exposure is performed for 90 seconds at the temperature (PEB) shown in Table 2, and development is performed with an aqueous 2.38 mass% tetramethylammonium hydroxide solution, followed by rinsing with distilled water to obtain a resist pattern profile.

A pattern formed on a 140 nm trench pattern (line / space = 1/1) obtained on a silicon wafer (6 inches) was cross-sectioned using a scanning electron microscope measuring SEM S-9260 manufactured by Hitachi, Ltd. The pattern shape was evaluated.
[PEB temperature dependence]
First, ARC-29A-8 manufactured by Brewer Science was applied to a silicon wafer at a thickness of 78 nm using a spin coater, dried, and then the positive photoresist composition obtained thereon was applied thereto. (SB) Dry for 90 seconds, produce a positive photoresist film of about 0.3 μm, and expose it with an ArF excimer laser (ArF stepper made by ISI having a wavelength of 193 nm, NA = 0.6), and heating after exposure The treatment was carried out at the temperature (PEB) shown in Table 2 for 90 seconds, developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, and rinsed with distilled water to obtain 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.

The exposure of the isolated contact hole pattern with a mask size of 180 nm is performed at an exposure amount that reproduces the isolated contact hole with a mask size of 180 nm at 140 nm, and post-exposure heating (PEB) is performed at + 2 ° C. and − The measurement is performed at two temperatures of 2 ° C. (for example, 98 ° C. and 102 ° C. when the PEB temperature shown in the table is 100 ° C.), and the obtained contact hole patterns are measured, and their diameter L ₁ and L ₂ was determined. The PEB temperature dependency was defined as a change in diameter per 1 ° C. PEB temperature change, and was calculated by the following formula.

PEB temperature dependency (nm / ° C.) = | L ₁ −L ₂ | / 4
[Exposure margin]
Fluctuation rate of the line width of the 130 nm line pattern obtained when the exposure amount for reproducing the line width of the 130 nm line and space pattern (line / space = 1/1) is changed ± 5% [(fluctuation width / 130) × 100] (%) was used as an index of exposure margin. The smaller this value, the better.

  The evaluation results are shown in Table 2 above.

  From the results in Table 2, it can be seen that the composition of the present invention is excellent in the above performances.

Claims (2)

(A) A resin containing a repeating unit represented by the following general formula (1), which increases the dissolution rate in an alkali developer by the action of an acid, and (B) generates an acid upon irradiation with actinic rays or radiation. A positive resist composition containing a compound.

In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² represents a monovalent organic group, and L ¹ represents a divalent linking 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.