JP2009086358A - Positive resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems relating to techniques for improving performances in micoprocessing of a semiconductor element using actinic rays or radiation, in particular, a KrF excimer laser beam, to provide a chemical amplification-type positive resist composition having high sensitivity and high resolution, suppressing generation of standing waves and giving a rectangular profile even when a high-reflection substrate is used as it is without applying an antireflection film, and to provide a pattern forming method using the composition. <P>SOLUTION: The positive resist composition includes: a resin containing a repeating unit having a structure expressed by general formula (I) and absorption at a wavelength of 248 nm, of which solubility in an alkali developer increases under an action of an acid; and a compound capable of generating an acid upon irradiation with actinic rays or radiation. The pattern forming method uses the positive resist composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a positive resist composition that can be suitably used in the manufacture of implantation resists, semiconductor integrated circuit elements, integrated circuit manufacturing masks, printed wiring boards, liquid crystal panels, and the like.

  An early chemically amplified positive resist composition comprising a photoacid generator and a resin protected with an acid-decomposable group is disclosed in, for example, Patent Document 1 (US Pat. No. 4,491,628). This chemically amplified positive resist composition generates an acid in the exposed area by irradiation with radiation such as far ultraviolet light, and dissolves in the developer in the active radiation irradiated area and non-irradiated area by a reaction using this acid as a catalyst. It is a pattern forming material that changes the properties and forms a pattern on a substrate.

  Various positive resist compositions containing a resin protected with an acid-decomposable group have been known so far. For example, Patent Document 2 (Japanese Patent Application Laid-Open No. 5-249682) discloses an alkoxy (acetal) group. A resist composition using a protected polyhydroxystyrene resin is disclosed in Patent Document 3 (Japanese Patent Application Laid-Open No. 9-21866) using a polyhydroxystyrene resin protected with two different acid-decomposable groups. Patent Document 4 (Japanese Patent Laid-Open No. 2000-352822) discloses a resist composition using a resin protected by an acetal group having a heterocyclic group at the terminal via a linking group. JP-A-2002-49156 discloses a resist composition using a polyhydroxystyrene resin protected with two different types of acetal groups. To 04-246326 JP) a resist composition using a polyhydroxystyrene resin protected by an acid decomposable group containing a group (heterocyclic) having absorption at a wavelength of 248nm is disclosed.

  However, a general positive resist composition does not use an antireflective film as in the case of forming a pattern for implantation such as ion implantation, and has a strong standing when a highly reflective substrate is used as it is. Improvements were desired because of the generation of waves. Further, improvement in sensitivity and resolution has been desired.

U.S. Pat. No. 4,491,628 JP-A-5-249682 JP-A-9-21866 JP 2000-352822 A JP 2002-49156 A JP 2004-246326 A

  The object of the present invention is to suppress the occurrence of standing waves even when a highly reflective substrate is used as it is without using an antireflection film, to obtain a rectangular profile, and to perform chemical amplification with high sensitivity and high resolution. An object of the present invention is to provide a type positive resist composition.

  As a result of intensive studies by the inventors, the object of the present invention has been achieved by the following constitution.

<1>
(A) a resin having a structure represented by the general formula (I) and containing a repeating unit having absorption at a wavelength of 248 nm and having increased solubility in an alkaline developer by the action of an acid; Alternatively, a positive resist composition comprising a compound that generates an acid upon irradiation with radiation.
In formula (I),
Ra and Rb are each independently a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group Represents an alkylcarbonyloxy group or an aralkyl group.
Z ¹ represents a non-acid-decomposable group. When a plurality of Z ¹ are present, they may be connected to each other to form a ring.
Y represents a single bond or a linking group.
m represents 1 or 2.

<2>
The positive resist composition as described in <1> above, wherein the repeating unit represented by formula (I) is a repeating unit represented by formula (Ia).
In formula (Ia),
Ra represents a hydrogen atom or a methyl group.
Z ¹ represents a non-acid-decomposable group.

<3>
The positive resist composition as described in <1> above, wherein the repeating unit represented by the general formula (I) is a repeating unit represented by the formula (Ib).
In formula (Ib),
Ra represents a hydrogen atom or a methyl group.
Z ¹ each independently represents a non-acid-decomposable group. Z ¹ may be bonded to each other to form a ring.

<4>
<1> to <1> above, wherein in the repeating unit represented by formula (I), Z ¹ is a group containing one or more benzene rings and a group having absorption at a wavelength of 248 nm. The positive resist composition according to any one of <3>.

<5>
<1> to <1> above, wherein in the repeating unit represented by the general formula (I), Z ¹ is a group containing two or more benzene rings and a group having absorption at a wavelength of 248 nm. The positive resist composition according to any one of <4>.

<6>
<1> to <1> above, wherein in the repeating unit represented by the general formula (I), Z ¹ is a group containing three or more benzene rings and a group having absorption at a wavelength of 248 nm. The positive resist composition according to any one of <5>.

<7>
<1> to <1> above, wherein the resin containing the repeating unit represented by formula (I) further contains at least one repeating unit represented by formula (A1) or (A2) The positive resist composition according to any one of <6>.
In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid, and when there are a plurality of groups, they may be the same or different.
S ₁ represents an arbitrary substituent, and when there are a plurality of S _{1 s} , they may be the same or different.
In the general formula (A2), X represents a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, an acyl group, an acyloxy group, a cycloalkyl group, an aryl group, a carboxyl group, an alkyloxycarbonyl group. Represents an alkylcarbonyloxy group or an aralkyl group.
A ₂ represents a group containing a group that decomposes by the action of an acid.

<8>
(B) The positive resist composition as described in any one of <1> to <7> above, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is oxime sulfonate or diazodisulfone.

<9>
Furthermore, it contains a compound that has a proton acceptor functional group and generates a compound that is decomposed by irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition as described in any one of <1> to <8> above.

<10> The positive resist composition as described in <2> above, wherein the repeating unit represented by the general formula (I) is a repeating unit represented by the formula (Iaa).
In the formula (Iaa),
Z ^{1 ′} represents an aryl group.

<11> The positive resist composition as described in <3> above, wherein the repeating unit represented by the general formula (I) is a repeating unit represented by the formula (Ibb).
In formula (Ib),
Z ^{1 ′} each independently represents an aryl group. Z ^{1 ′} may be bonded to each other to form a ring.

  <12> The positive resist composition as described in any one of <1> to <8>, wherein the resin (A) has a weight average molecular weight (Mw) in the range of 1,000 to 200,000. .

  <13> The positive resist composition as described in any one of <1> to <8> above, wherein the resin (A) has a weight average molecular weight (Mw) in the range of 1,000 to 100,000. .

  <14> The positive resist composition as described in any one of <1> to <8> above, wherein the resin (A) has a weight average molecular weight (Mw) in the range of 1,000 to 50,000. .

  <15> The positive resist composition as described in any one of <1> to <8> above, wherein the resin (A) has a weight average molecular weight (Mw) in the range of 1,000 to 25,000. .

  <16> The positive resist composition as described in any one of <1> to <12> above, further comprising (C) an organic basic compound.

  <17> The positive resist composition as described in any one of <1> to <13> above, further comprising (D) a surfactant.

  <18> The positive resist composition as described in any one of <1> to <14>, further comprising a solvent.

  <19> The positive resist composition as described in <15> above, which contains propylene glycol monomethyl ether acetate as the solvent.

  <20> The positive resist composition as described in <15> above, further containing propylene glycol monomethyl ether as the solvent.

  <21> The positive resist composition as described in <1> to <17> above, which is exposed by irradiation with KrF, electron beam, X-ray or EUV.

  <22> A pattern forming method comprising: forming a resist film from the resist composition according to any one of <1> to <21>, exposing and developing the resist film.

  Since the positive resist composition of the present invention contains a specific acid-decomposable resin, even when coated on a substrate having a highly reflective surface without using an antireflection film, the occurrence of standing waves is substantially reduced. Excellent profile with good sensitivity, high sensitivity and high resolution.

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

  The positive resist composition of the present invention is a resin containing a repeating unit represented by the general formula (I), which is insoluble or hardly soluble in an alkali developer and has increased solubility in an alkali developer by the action of an acid ( A) The compound (B) which generates an acid upon irradiation with actinic rays or radiation is contained.

  Hereinafter, each component blended in the positive resist composition of the present invention will be described.

[1] Resin containing repeating unit represented by general formula (I) The resist composition of the present invention contains a repeating unit having a structure represented by general formula (I) and having absorption at a wavelength of 248 nm. And a resin (A) whose solubility in an alkaline developer is increased by the action of an acid.
The resin (A) is preferably insoluble or hardly soluble in an alkali developer.

In formula (I),
Ra and Rb are each independently a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group Represents an alkylcarbonyloxy group or an aralkyl group. A hydrogen atom or an alkyl group is preferable, and a hydrogen atom is most preferable.
Z ¹ represents a non-acid-decomposable group. When a plurality of Z ¹ are present, they may be connected to each other to form a ring.
Y represents a single bond or a linking group.
m represents 1 or 2.

  The repeating unit represented by the general formula (I) is preferably a repeating unit represented by the following formula (Ia) or a repeating unit represented by the formula (Ib).

In formula (Ia),
Ra represents a hydrogen atom or a methyl group.
Z ¹ represents a non-acid-decomposable group.

In formula (Ib),
Ra represents a hydrogen atom or a methyl group.
Z ¹ each independently represents a non-acid-decomposable group. Z ¹ may be bonded to each other to form a ring.

  The repeating unit represented by the general formula (I) is more preferably a repeating unit represented by the following formula (Iaa) or a repeating unit represented by the formula (Ibb).

In formula (Iaa), Z ^{1 ′} represents an aryl group.

In formula (Ib), Z ^{1 ′} each independently represents an aryl group. Z ^{1 ′} may be bonded to each other to form a ring.

The alkyl group as Ra and Rb may have a substituent and may be linear or branched. As a linear alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, For example, a methyl group, an ethyl group, n-propyl group, n-butyl group, sec-butyl group, t-butyl Group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group and the like. As a branched alkyl group, Preferably it is C3-C30, More preferably, it is 3-20, for example, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, Examples include i-hexyl group, t-hexyl group, i-heptyl group, t-heptyl group, i-octyl group, t-octyl group, i-nonyl group, t-decanoyl group and the like.
The alkoxy group as Ra and Rb may have a substituent, for example, the above alkoxy group having 1 to 8 carbon atoms, for example, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyl. An oxy group, a cyclohexyloxy group, etc. can be mentioned.
Examples of the halogen atom as Ra and Rb include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
The acyl group as Ra and Rb may have a substituent, for example, an acyl group having 2 to 8 carbon atoms, specifically, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, Preferred examples include a pivaloyl group and a benzoyl group.

The acyloxy group as Ra and Rb may have a substituent, and is preferably an acyloxy group having 2 to 8 carbon atoms, such as an acetoxy group, a propionyloxy group, a butyltrioxy group, a valeryloxy group, a pivaloyloxy group, A hexanoyloxy group, an octanoyloxy group, a benzoyloxy group, etc. can be mentioned.
The cycloalkyl group as Ra and Rb may have a substituent, may be monocyclic, polycyclic, or bridged. For example, the cycloalkyl group may have a bridged structure. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic type include groups having a bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, Examples thereof include a camphanyl group, a dicyclopentyl group, an α-pinel group, a tricyclodecanyl group, a tetocyclododecyl group, an androstanyl group, and the following structures. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

Preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin group, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecanyl group. And cyclododecanyl group. More preferred are an adamantyl group, a decalin group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, and a tricyclodecanyl group.
Examples of the substituent of these alicyclic structures include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group. Preferred examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the substituent that the alkyl group and the alkoxy group may have include a hydroxyl group, a halogen atom, and an alkoxy group (preferably having 1 to 4 carbon atoms).

  Further, further substituents that the above group may have include hydroxyl group, halogen atom (fluorine, chlorine, bromine, iodine), nitro group, cyano group, the above alkyl group, methoxy group, ethoxy group, hydroxy group. Alkoxy groups such as ethoxy group, propoxy group, hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group and t-butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, benzyl group and 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, propenyl Such as oxy group, allyloxy group, butenyloxy group, etc. Rukeniruokishi group, said aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group.

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

The aryl group as Ra and Rb may have a substituent, and preferably has 6 to 14 carbon atoms, and examples thereof include a phenyl group, a xylyl group, a toluyl group, a cumenyl group, a naphthyl group, and an anthracenyl group. Can be mentioned.
The alkyloxycarbonyl group as Ra and Rb may have a substituent and preferably has 2 to 8 carbon atoms, and examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, and a propoxycarbonyl group.
The alkylcarbonyloxy group as Ra and Rb may have a substituent, and preferably has 2 to 8 carbon atoms, and examples thereof include a methylcarbonyloxy group and an ethylcarbonyloxy group.
The aralkyl group as Ra and Rb may have a substituent and is preferably an aralkyl group having 7 to 16 carbon atoms, for example, a benzyl group.

Z ¹ represents a non-acid-decomposable group. A non-acid-decomposable group is a group that is not an acid-decomposable group (a group that decomposes by the action of an acid to produce an alkali-soluble group), that is, an acid generated from a photoacid generator or the like upon exposure to a hydroxyl group, A group that does not generate an alkali-soluble group such as a carboxy group.

Specific examples of the non-acid-decomposable group as Z ¹ include, for example, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an acyl group, —OC (═O) R ⁰¹ , —OC ( = O) OR ⁰¹ , -C (= O) OR ⁰¹ , -C (= O) N (R ⁰² ) R ⁰¹ , -N (R ⁰² ) C (= O) R ⁰¹ , -N (R ⁰² ) C (= O) OR ⁰¹ , -N (R ⁰² ) SO ₂ R ⁰¹ , -SR ⁰¹ ,-
Examples include SO ₂ R ⁰¹ , —SO ₃ R ⁰¹ , and —SO ₂ N (R ⁰² ) R ⁰¹ .
R ⁰¹ and R ⁰² are each independently an alkyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyl Represents an oxy group or an aralkyl group.
R ⁰¹ and R ⁰² alkyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, or aralkyl group Is a group defined similarly to Ra and Rb in the general formula (I).

The alkyl group as Z ¹ may have a substituent as long as it is a non-acid-decomposable group, and may be linear or branched. As a linear alkyl group, Preferably it is C1-C30, More preferably, it is 1-20, for example, a methyl group, an ethyl group, n-propyl group, n-butyl group, sec-butyl group, n-pentyl. Group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decanyl group and the like. As a branched alkyl group, Preferably it is C3-C30, More preferably, it is 3-20, for example, i-propyl group, i-butyl group, i-pentyl group, i-hexyl group, i-heptyl group, An i-octyl group, an i-nonyl group, etc. are mentioned.

The halogen atom, cycloalkyl group, aryl group, alkoxy group and acyl group as Z ¹ are the same as those exemplified as the respective groups as Ra and Rb.

Z ¹ is preferably an aryl group.

General formula (I) has absorption at a wavelength of 248 nm.
In particular, Z ¹ may have any group having at least one benzene ring and having absorption at a wavelength of 248 nm as long as it is a group having absorption to some extent at 248 nm, but the absorption is preferably higher. .
The group having absorption at a wavelength of 248 nm has at least one benzene ring, but preferably further has a conjugated substituent. Further, a group having two or more benzene rings is preferable, and a group having three or more benzene rings is more preferable.
Here, the benzene ring is a ring structure composed of 6 carbon atoms, and includes the largest number of non-integrated double bonds (most numerous conjugated double bonds) in the ring.

Examples of the conjugated substituent include —C═C—, —C≡C—, —C (═O) —, —CN, —NO _{2 and the} like. More preferably, -C = C-, -C≡C-, and -C (= O)-can be mentioned. More preferably, -C (= O)-can be mentioned.

Z ¹ may have an arbitrary group together with a group having absorption at 248 nm, such as an alkylene group, a carbonyl group, —O—, —S—, —C (═S) —, an ester group, A thioester group, an alkenyl group, an alkynyl group, —NHC (═O) —, —C (═O) NH—, —NH—, more preferably an alkylene group, a carbonyl group, —O—, an ester group, an alkenyl group; is there.
Note that the group containing at least one benzene ring and a group having absorption at 248 nm in Z ¹ may be a group itself having at least one benzene ring and absorption at 248 nm.
The number of atoms constituting the group containing a group having absorption at 248 nm is preferably 100 or less, and more preferably 50 or less.

The group as Z ¹ is preferably an arylcarbonyl group, a condensed ring aryl group, a condensed ring arylcarbonyl group, a heteroarylcarbonyl group, a condensed ring heteroaryl group, a condensed ring heteroarylcarbonyl group, or an alkyl group having an arylcarbonyl group. An alkyl group having a condensed ring aryl group, an alkyl group having a condensed ring arylcarbonyl group, an alkyl group having a heteroarylcarbonyl group, an alkyl group having a condensed heteroaryl group, an alkyl group having a condensed ring heteroarylcarbonyl group, etc. Is mentioned.
Moreover, it is not necessary to limit to an aromatic ring such as a phenyl group, and a heterocyclic ring or the like can be used as long as it has a 248 nm absorption. In this case as well, it is more preferable to have a conjugated double bond (including a carbonyl group).

  The molar extinction coefficient ε at 248 nm of the monomer corresponding to the repeating unit represented by the general formula (I) is preferably 200 or more, more preferably 200 to 500,000, more preferably 300 to 300,000, particularly preferably 500 to 200000, most preferably 1000-100000. The molar extinction coefficient ε here is a value in a tetrahydrofuran solution (23 ° C.).

In the present invention, since the resin has a group having absorption at 248 nm, the transmittance of light at 248 nm of the film after being applied to the substrate can be controlled to a desired value. Can be changed. Therefore, the transmittance can be controlled without depending on the film thickness.
For example, the transmittance at 248 nm with a film thickness of 4000 mm is 90% or less. Preferably, it is 30 to 85%, more preferably 35 to 80%, still more preferably 38 to 78%, and most preferably 40 to 75%.
For example, when the film thickness is 1900 mm, the transmittance at 48 nm is 90% or less. Preferably, it is 30 to 88%, more preferably 40 to 85%, still more preferably 50 to 83%, and most preferably 60 to 80%.
The transmittance is preferably larger in terms of resolution and sensitivity, and smaller in terms of standing wave suppression. The film thickness is not limited to the above example.

  Y represents a single bond or a linking group, and the linking group is preferably a divalent linking group or a trivalent amino group. m represents 1 or 2.

  Here, the trivalent amino group represents the following structure. Further, substituents in the trivalent amino group may be bonded to each other to form a ring structure.

Examples of the linking group include an alkylene group, an arylene group, a carbonyl group, a sulfide group, a sulfone group, —COO—, —CONH—, —SO ₂ NH—, —CF ₂ —, —CF ₂ CF ₂ —, —OCF. ₂ O—, —CF ₂ OCF ₂ —, —SS—, —CH ₂ SO ₂ CH ₂ —, —CH ₂ COCH ₂ —, —COCF ₂ CO—, —COCO—, —OCOO—, —OSO ₂ O— , Ether group (oxygen atom), thioether group (sulfur atom), —NH— group, trivalent amino group, acyl group, alkylsulfonyl group, —CH═CH—, —C≡C—, aminocarbonylamino group, An aminosulfonylamino group, and the like, which may have a substituent.

The connection as Y preferably has 15 or less carbon atoms, more preferably 10 or less carbon atoms.
Y is preferably a direct bond, ether group (oxygen atom), thioether group (sulfur atom), -NH- group, trivalent amino group, Y is more preferably a direct bond, ether group (oxygen atom), -NH- Group, a trivalent amino group, particularly preferably an ether group (oxygen atom), -NH- group, and a trivalent amino group, and more preferably an ether group (oxygen atom).

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

  (A) It is preferable that the resin containing the repeating unit represented by the general formula (I) further includes a repeating unit represented by the general formula (A1) or (A2).

In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid.
The group containing a group capable of decomposing by the action of an acid is a group in which A ₁ is eliminated, resulting in a hydroxyl group in the repeating unit represented by the general formula (A1), that is, an acid-decomposable group itself. It may be a group containing an acid-decomposable group, that is, a group in which an alkali-soluble group such as a hydroxyl group or a carboxyl group is generated in a residue that is decomposed by the action of an acid and bonded to a repeating unit.

Examples of the group containing a group capable of decomposing by the action of an acid include tertiary alkyl groups such as t-butyl group and t-amyl group, t-butoxycarbonyl group, t-butoxycarbonylmethyl group, -C (L ₁ ) ( An acetal group represented by L ₂ ) —O—Z ² can be mentioned.
L ₁ and L ₂ may be the same or different and each represents an atom or group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group.
Z ² represents an alkyl group, a cycloalkyl group or an aralkyl group.
Z ² and L ₁ may be bonded to each other to form a 5- or 6-membered ring.

Examples of the aralkyl group in L ₁ , L ₂ and Z ² include those having 7 to 15 carbon atoms such as benzyl group and phenethyl group. These groups may have a substituent.

Preferable substituents that the aralkyl group has include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acylamino group, a sulfonylamino group, an alkylthio group, an arylthio group, an aralkylthio group, and the like. Examples of the aralkyl group having a substituent include an alkoxybenzyl group, a hydroxybenzyl group, and a phenylthiophenethyl group.
The range of the number of carbon atoms of the substituent which the aralkyl group in L ₁ , L ₂ and Z ² may have is preferably 12 or less.

Examples of the 5- or 6-membered ring formed by combining Z ² and L ₁ with each other include a tetrahydropyran ring and a tetrahydrofuran ring.

In the present invention, Z ² is preferably a linear or branched alkyl group.
Thereby, the effect of the present invention becomes more remarkable.

When there are a plurality of S _{1 s,} each independently represents an arbitrary substituent, for example, an alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, aralkyl group, aralkyloxy group, hydroxy group, halogen atom , A cyano group, a nitro group, a sulfonylamino group, an alkylthio group, an arylthio group, and an aralkylthio group.
For example, as an alkyl group and a cycloalkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, an octyl group, A linear or branched alkyl group having 1 to 20 carbon atoms such as a dodecyl group or a cycloalkyl group is preferable. These groups may further have a substituent.
Further preferred substituents that may be included are alkyl group, alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, sulfonylamino group, alkylthio group, arylthio group, aralkylthio group, thiophenecarbonyloxy Group, a thiophenemethylcarbonyloxy group, a heterocyclic residue such as a pyrrolidone residue, and the like, and a substituent having 12 or less carbon atoms is preferable.

  Examples of the alkyl group having a substituent include a cyclohexylethyl group, an alkylcarbonyloxymethyl group, an alkylcarbonyloxyethyl group, a cycloalkylcarbonyloxymethyl group, a cycloalkylcarbonyloxyethyl group, an arylcarbonyloxyethyl group, and an aralkylcarbonyloxyethyl group. , Alkyloxymethyl group, cycloalkyloxymethyl group, aryloxymethyl group, aralkyloxymethyl group, alkyloxyethyl group, cycloalkyloxyethyl group, aryloxyethyl group, aralkyloxyethyl group, alkylthiomethyl group, cycloalkylthiomethyl Group, arylthiomethyl group, aralkylthiomethyl group, alkylthioethyl group, cycloalkylthioethyl group, arylthioethyl group, aralkyl Oechiru group, and the like.

  The alkyl group and cycloalkyl group in these groups are not particularly limited, and may further have a substituent such as the aforementioned alkyl group, cycloalkyl group, or alkoxy group.

  Examples of the alkylcarbonyloxyethyl group and cycloalkylcarbonyloxyethyl group include cyclohexylcarbonyloxyethyl group, t-butylcyclohexylcarbonyloxyethyl group, n-butylcyclohexylcarbonyloxyethyl group, and the like.

The aryl group is not particularly limited, but generally includes those having 6 to 14 carbon atoms such as a phenyl group, a xylyl group, a toluyl group, a cumenyl group, a naphthyl group, an anthracenyl group, and the above-mentioned alkyl groups and cycloalkyl groups. And may have a substituent such as an alkoxy group.
Examples of the aryloxyethyl group include a phenyloxyethyl group, a cyclohexylphenyloxyethyl group, and the like. These groups may further have a substituent.

Aralkyl is not particularly limited, and examples thereof include a benzyl group.
Examples of the aralkylcarbonyloxyethyl group include a benzylcarbonyloxyethyl group. These groups may further have a substituent.

Next, the repeating unit represented by general formula (A2) is demonstrated.
In the general formula (A2), X represents a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, an acyl group, an acyloxy group, a cycloalkyl group, an aryl group, a carboxyl group, an alkyloxycarbonyl group. Represents an alkylcarbonyloxy group or an aralkyl group. The details of each group are the same as Ra and Rb in the general formula (I). Preferably, a hydrogen atom or an alkyl group. More preferred is an alkyl group, and particularly preferred is a methyl group.

A ₂ represents a group containing a group that decomposes by the action of an acid.
The group containing a group that decomposes due to the action of an acid is a group in which A ₂ is eliminated, resulting in a carboxyl group in the repeating unit represented by the general formula (A2), that is, an acid-decomposable group itself. It may be a group containing an acid-decomposable group, that is, a group in which an alkali-soluble group such as a hydroxyl group or a carboxyl group is generated in a residue that is decomposed by the action of an acid and bonded to a repeating unit.

A ₂ is preferably a hydrocarbon group (preferably having a carbon number of 20 or less, more preferably 4 to 12), and a t-butyl group, a t-amyl group, or a hydrocarbon group having an alicyclic structure (for example, an alicyclic ring). The group itself and a group in which an alicyclic group is substituted on the alkyl group) are more preferable.
The alicyclic structure may be monocyclic or polycyclic. Specific examples include monocyclo, bicyclo, tricyclo, and tetracyclo structures having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These hydrocarbon groups having an alicyclic structure may have a substituent.
Examples of alicyclic structures are shown below.

  In the present invention, the alicyclic structure is preferably a monovalent alicyclic group as an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, or a norbornyl group. And 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 that the alicyclic ring may have include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group or a butyl group, more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. The alkyl group and the alkoxy group may have a further substituent. Examples of further substituents on the alkyl group and alkoxy group include a hydroxyl group, a halogen atom, and an alkoxy group.

  As the acid-decomposable group having an alicyclic structure, groups represented by the following general formula (pI) to general formula (pV) are preferable.

In the general formulas (pI) to (pV),
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 necessary atomic group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or 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 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 Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formulas (pI) to (pV), the alkyl group in R _{12 to} R ₂₅ may be either substituted or unsubstituted, and 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.

Examples of the alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom include those described above as the alicyclic structure.

Specific examples of groups (acid-decomposable groups) containing a group that decomposes by the action of an acid containing an alicyclic structure as A ₂ or a group that decomposes by the action of an acid are given below.

  Although the specific example of the repeating unit represented by general formula (A1) below is given, it is not limited to these.

  Although the specific example of the repeating unit represented by general formula (A2) below is given, it is not limited to these.

  The repeating unit represented by the general formula (A2) is preferably a repeating unit of t-butyl methacrylate.

  The repeating unit represented by the general formula (A2) is more preferably a repeating unit represented by the general formula (A2 ′).

In general formula (A2 ′),
AR represents a benzene ring, a naphthalene ring, or an anthracene ring, and each may have one or more substituents. Preferred substituents include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl and the like. Is a linear or branched alkyl group having 1 to 20 carbon atoms, or an alkoxy group, a hydroxyl group, a halogen atom, an aryl group, a cyano group, a nitro group, an acyl group, an acyloxy group, an acylamino group, a sulfonylamino group, an alkylthio group, Examples include arylthio groups, aralkylthio groups, thiophenecarbonyloxy groups, thiophenemethylcarbonyloxy groups, heterocyclic residues such as pyrrolidone residues, etc., but linear or branched alkyl groups having 1 to 5 carbon atoms, or alkoxy groups Is preferable from the viewpoint of resolution. More preferred is benzene, paramethylbenzene or paramethoxybenzene.
Rn represents an alkyl group or an aryl group.
AR and Rn may be bonded to each other to form a ring.
A represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkyloxycarbonyl group.

As the alkyl group in Rn, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, dodecyl group, etc. , Preferably a linear or branched alkyl group having 1 to 20 carbon atoms is used.
As the aryl group in Rn, those having 6 to 14 carbon atoms such as phenyl group, xylyl group, toluyl group, cumenyl group, naphthyl group, and anthracenyl group are preferable.
Preferred substituents that the above-mentioned group as Rn may have include alkoxy groups, hydroxyl groups, halogen atoms, nitro groups, acyl groups, acyloxy groups, acylamino groups, sulfonylamino groups, alkylthio groups, arylthio groups, Heterocyclic residues such as aralkylthio group, thiophenecarbonyloxy group, thiophenemethylcarbonyloxy group, pyrrolidone residue, etc. are mentioned, among them alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, A sulfonylamino group is preferred.

Examples of the alkyl group in A include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, dodecyl group, etc. A linear or branched alkyl group having 1 to 20 carbon atoms is preferable. These groups may have a substituent, and preferred substituents that may be included include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acyloxy group, an acylamino group, a sulfonylamino group, an alkylthio group, Examples include arylthio groups, aralkylthio groups, thiophenecarbonyloxy groups, thiophenemethylcarbonyloxy groups, and heterocyclic residues such as pyrrolidone residues. Among them, CF ₃ groups, alkyloxycarbonylmethyl groups, alkylcarbonyloxymethyl groups, hydroxy groups A methyl group, an alkoxymethyl group and the like are preferable.
Examples of the halogen atom in A include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the alkyl contained in the alkyloxycarbonyl group in A include the same alkyl groups as in A.

  Specific examples of the repeating unit represented by the general formula (A2 ′) are shown below, but are not limited thereto.

  The resin (A) preferably further has a repeating unit represented by the general formula (A4).

In general formula (A4),
R ₂ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a perfluoro group having 1 to 4 carbon atoms.
R ₃ represents a hydrogen atom, an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
q represents an integer of 0 to 4.
W represents a group that is not decomposed by the action of an acid.

  W represents a group that is not decomposed by the action of an acid (also referred to as an acid stabilizing group). Specifically, a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an acyl group, an alkylamide group, An arylamidomethyl group, an arylamide group, etc. are mentioned. The acid stabilizing group is preferably an acyl group or an alkylamide group, more preferably an acyl group, an alkylcarbonyloxy group, an alkyloxy group, a cycloalkyloxy group, or an aryloxy group.

  In the acid stable group of W, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group and t-butyl group. As the alkyl group, those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferable, and as the alkenyl group, carbon number such as vinyl group, propenyl group, allyl group and butenyl group. Those having 2 to 4 carbon atoms are preferable, those having 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group are preferable as alkenyl groups, and phenyl group, xylyl group and toluyl group are preferable as aryl groups. And those having 6 to 14 carbon atoms such as cumenyl group, naphthyl group and anthracenyl group are preferable. W may be at any position on the benzene ring, but is preferably a meta position or a para position of the styrene skeleton, particularly preferably a para position.

  Although the specific example of the repeating unit represented by general formula (A4) below is given, it is not limited to these.

  The resin (A) preferably further has a repeating unit composed of a (meth) acrylic acid derivative that is not decomposed by the action of an acid. Although a specific example is given below, it is not limited to this.

Resin (A) is a resin (acid-decomposable resin) whose solubility in an alkaline developer is increased by the action of an acid, and is decomposed by the action of an acid in an arbitrary repeating unit. Contains the resulting group (acid-decomposable group).
As described above, the repeating unit represented by the general formula (I), (A1) or (A2) may have an acid-decomposable group or may be contained in another repeating unit. Good.
Examples of the acid-decomposable group include those represented by —C (═O) —X ₁ —R ₀ other than those described above.
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- Examples include an oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue, and the like. X ₁ represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or -NHSO ₂
NH- is represented.
The content of the repeating unit having an acid-decomposable group in the resin (A) is preferably 5 to 95 mol%, more preferably 10 to 60 mol%, and particularly preferably 15 to 50 mol% in all repeating units. It is.

As for the content rate of the repeating unit represented by general formula (I) in resin (A), 1-70 mol% is preferable in all the repeating units, More preferably, it is 1-50 mol%, Most preferably, it is 1- 30 mol%.
As for the content rate of the repeating unit represented by general formula (A1) in resin (A), 20-90 mol% is preferable in all the repeating units, More preferably, it is 30-80 mol%, Especially preferably, 40- 70 mol%.
The content of the repeating unit represented by the general formula (A2) in the resin (A) is preferably 0 to 90 mol%, more preferably 5 to 75 mol%, and particularly preferably 10 to 10 mol% in all repeating units. 60 mol%.

  The resin (A) may further have a repeating unit represented by the general formula (A4), which is preferable from the viewpoints of improving the film quality and suppressing the decrease in film thickness of the unexposed area. The content of the repeating unit represented by the general formula (4) is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and particularly preferably 0 to 40 mol% in each of all the repeating units. 30 mol%.

  The resin (A) is copolymerized with other polymerizable monomers suitable so that an alkali-soluble group such as a phenolic hydroxyl group or a carboxyl group can be introduced in order to maintain good developability for an alkali developer. In order to improve the film quality, other hydrophobic polymerizable monomers such as alkyl acrylate and alkyl methacrylate may be copolymerized.

Monomers corresponding to the repeating units represented by the general formulas (I) and (A2) include (meth) acrylic acid chloride and an alcohol compound in a solvent such as THF, acetone, and methylene chloride, such as triethylamine, pyridine, and DBU. It can be synthesized by esterification in the presence of a basic catalyst. A commercially available product may be used.
The monomer corresponding to the repeating unit represented by the general formula (A1) is a hydroxy-substituted styrene monomer and a vinyl ether compound in a solvent such as THF and methylene chloride, such as p-toluenesulfonic acid and p-toluenesulfonic acid pyridine salt. It can be synthesized by acetalization in the presence of an acidic catalyst or by t-Boc protection using t-butyl dicarbonate in the presence of a basic catalyst such as triethylamine, pyridine, DBU or the like. A commercially available product may be used.

The weight average molecular weight (Mw) of the resin (A) is preferably in the range of 1000 to 200,000, respectively. 200,000 or less is preferable from the viewpoint of the dissolution rate and sensitivity of the resin itself in alkali. The dispersity (Mw / Mn) is preferably 1.0 to 3.0, more preferably 1.0 to 2.5, and particularly preferably 1.0 to 2.0.
Among them, the weight average molecular weight (Mw) of the resin is preferably in the range of 1,000 to 200,000, more preferably in the range of 1,000 to 100,000, and particularly preferably 1,000. Is in the range of ~ 50,000, most preferably in the range of 1,000-25,000.
Here, the weight average molecular weight is defined by a polystyrene conversion value of gel permeation chromatography.

Resin (A) having a dispersity of 1.5 to 2.0 can be synthesized by radical polymerization using an azo polymerization initiator. Further preferred resin (A) having a dispersity of 1.0 to 1.5 can be synthesized by living radical polymerization.

Moreover, you may use resin (A) in combination of 2 or more types.
The total amount of the resin (A) added is generally 10 to 99% by mass, preferably 20 to 99% by mass, particularly preferably 30 to 99% by mass, based on the total solid content of the positive resist composition. %.

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

[2] Compound that generates acid upon irradiation with actinic ray or radiation The resist composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”).
Examples of the acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, a microresist, and the like, KrF excimer laser light, electron Known compounds that generate acid upon irradiation with actinic rays or radiation such as rays and EUV, and mixtures thereof can be appropriately selected and used.
Examples of such an acid generator include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, o-nitrobenzyl sulfonates, and preferably oxime sulfonates. Or diazodisulfone.

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

  Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
It is also possible to form the two members to ring structure of R ₂₀₁ to R _203, an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Examples of the group formed by combining two of R _{201 to} R ₂₀₃ with each other include an alkylene group (eg, butylene group, pentylene group).
Z ⁻ represents a non-nucleophilic anion.

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

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

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

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

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

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

  The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferably 2 to 7 carbon atoms, acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (Preferably having 1 to 15 carbon atoms), alkyliminosulfonyl group (preferably having 2 to 15 carbon atoms), aryl Ruoxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 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 aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.

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

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

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

  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. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

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

Examples of the non-nucleophilic anion of Z ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the 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 compounds, namely, compounds containing an 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 triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. 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, more 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 which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having 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, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, 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 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. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl 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 alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

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

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

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure. It may contain an atom, an ester bond or an amide bond. Examples of the group formed by bonding any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y to each other include a butylene group and a pentylene group.

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

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. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

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 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 2-15. 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 group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

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 _7c .

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

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 general formulas (ZII) and (ZIII),
R ₂₀₄ to 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. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _207, 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 Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, 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 (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

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

  Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI), and those having a molecular weight of 3000 or less are preferable.

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 independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  As the acid generator, a compound capable of generating an acid having one sulfonic acid group or imide group is preferable, more preferably a compound generating a monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group that generates or a compound that generates an imide acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, and even more preferably, a fluorinated substituted alkane It is a sulfonium salt of sulfonic acid, fluorine-substituted benzenesulfonic acid, fluorine-substituted imide acid or fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

<Sulfonic acid generator>
A compound that generates sulfonic acid upon irradiation with actinic rays or radiation, which is preferable as an acid generator (also referred to as a sulfonic acid generator), is a compound that generates sulfonic acid upon irradiation with actinic rays or radiation, such as KrF excimer laser light, electron beam, EUV Examples of such compounds are diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

From the viewpoint of improving image performance such as resolution and pattern shape, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, and disulfones are preferable.
From the viewpoint of remaining low standing waves, more preferred are imide sulfonate, oxime sulfonate, diazodisulfone, and disulfone, and still more preferred are oxime sulfonate and diazodisulfone.
The sulfonic acid generator can be synthesized by a known method such as a synthesis method described in JP-A-2002-27806.

  Examples of particularly preferred sulfonic acid generators are given below.

The content of the acid generator is 0.5 to 20% by mass, preferably 1 to 15% by mass, particularly preferably 1 to 10% by mass, based on the total solid content of the resist composition. That is, 1% by mass or more is preferable in terms of sensitivity and line edge roughness, and 10% by mass or less is preferable in terms of resolution, pattern shape, and film quality.
In addition, one type of acid generator may be used, or two or more types may be mixed and used. For example, as the acid generator, a compound that generates aryl sulfonic acid upon irradiation with active light or radiation and a compound that generates alkyl sulfonic acid upon irradiation with active light or radiation may be used in combination.

<Carboxylic acid generator>
As the acid generator, a compound that generates a carboxylic acid upon irradiation with actinic rays or radiation (also referred to as a carboxylic acid generator) may be used.
As the carboxylic acid generator, a compound represented by the following general formula (C) is preferable.

In the general formula (C), R _{21 to} R ₂₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, and R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group. Z represents a sulfur atom or an iodine atom. When Z is a sulfur atom, p is 1, and when Z is an iodine atom, p is 0.

In the general formula (C), R _{21 to} R ₂₃ each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group, and these groups may have a substituent.
Examples of the substituent that the alkyl group, cycloalkyl group or alkenyl group may have include a halogen atom (a chlorine atom, a bromine atom, a fluorine atom, etc.), an aryl group (a phenyl group, a naphthyl group, etc.), a hydroxy group, An alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) etc. can be mentioned.
Examples of the substituent that the aryl group may have include a halogen atom (chlorine atom, bromine atom, fluorine atom, etc.), nitro group, cyano group, alkyl group (methyl group, ethyl group, t-butyl group, t -Amyl group, octyl group, etc.), hydroxy group, alkoxy group (methoxy group, ethoxy group, butoxy group, etc.) and the like.

R _{21 to} R ₂₃ are preferably each independently an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aryl group having 6 to 24 carbon atoms. And more preferably an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 18 carbon atoms, and particularly preferably an aryl group having 6 to 15 carbon atoms. Each of these groups may have a substituent.

R ₂₄ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group.
Examples of the substituent that the alkyl group, cycloalkyl group, and alkenyl group may have are the same as those described as examples of the substituent when R ₂₁ is an alkyl group. Examples of the substituent for the aryl group, the R ₂₁ may be the same as those mentioned as examples of the substituent when it is an aryl group.

R ₂₄ is preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 24 carbon atoms, and more Preferably, they are a C1-C18 alkyl group, a C3-C18 cycloalkyl group, and a C6-C18 aryl group, Most preferably, a C1-C12 alkyl group, C3-C3 A cycloalkyl group having 12 carbon atoms and an aryl group having 6 to 15 carbon atoms. Each of these groups may have a substituent.

Z represents a sulfur atom or an iodine atom. p is 1 when Z is a sulfur atom, and 0 when Z is an iodine atom.
Two or more cation moieties of formula (C) are bonded by a single bond or a linking group (for example, -S-, -O-, etc.) to form a cation structure having a plurality of cation moieties of formula (C). May be.

  Although the preferable specific example of a carboxylic acid generator is given to the following, of course, it is not limited to these.

When the carboxylic acid generator is used, the content in the positive resist composition of the present invention is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, based on the total solid content of the composition. Especially preferably, it is 0-3 mass%. In addition, these compounds that generate carboxylic acid upon irradiation with actinic rays or radiation may be used alone or in combination of two or more.
The carboxylic acid generator can be synthesized by a known method such as the synthesis method described in JP-A-2002-27806.
When the sulfonic acid generator (B) and the carboxylic acid generator (C) are used in combination, the C / B (mass ratio) is usually 99.9 / 0.1-50 / 50, preferably 99 / 1-60. / 40, particularly preferably 98/2 to 70/30.

[3] A compound that has a proton acceptor functional group and generates a compound that is decomposed by irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition of the present invention has a proton acceptor functional group in terms of sensitivity, resolution, and line edge roughness, and is decomposed by irradiation with actinic rays or radiation, resulting in a decrease or disappearance of proton acceptor properties. Or a compound that generates a compound that has been changed from proton acceptor property to acidity (hereinafter also referred to as “compound (PA)”).

A compound (PA) generated by decomposition by irradiation with actinic rays or radiation, wherein the proton acceptor property is lowered, disappears, or is changed from proton acceptor property to acid, is represented by the following general formula (PA-I) Mention may be made of the compounds represented.
Q-A- (X) nBR (PA-1)
In general formula (PA-I),
Q represents a sulfo group (—SO ₃ H) or a carboxyl group (—CO ₂ H).
A represents a divalent linking group.
X represents —SO ₂ — or —CO—.
n represents 0 or 1.
B represents a single bond, an oxygen atom or -N (Rx)-. Rx represents a hydrogen atom or a monovalent organic group.
R represents a monovalent organic group having a proton acceptor functional group or a monovalent organic group having an ammonium group.

  The divalent linking group in A is preferably a divalent linking group having 2 to 12 carbon atoms, and examples thereof include an alkylene group and a phenylene group. More preferably, it is an alkylene group having at least one fluorine atom, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is particularly preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, and more preferably, the carbon atom bonded to the Q site has a fluorine atom. Further, a perfluoroalkylene group is preferable, and a perfluoroethylene group, a perfluoropropylene group, and a perfluorobutylene group are more preferable.

The monovalent organic group in Rx preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group in Rx may have a substituent, preferably a linear or branched alkyl group having 1 to 20 carbon atoms, and has an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain. May be. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
Examples of the alkyl group having a substituent include groups in which a linear or branched alkyl group is substituted with a cycloalkyl group (for example, an adamantylmethyl group, an adamantylethyl group, a cyclohexylethyl group, a camphor residue, etc.). .
The cycloalkyl group in Rx may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom in the ring. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Rx may have a substituent and is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group and a naphthyl group.
The aralkyl group in Rx may have a substituent, preferably an aralkyl group having 7 to 20 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group.
The alkenyl group in Rx may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group mentioned as Rx.

  The proton acceptor functional group in R is a group capable of electrostatically interacting with protons or a functional group having electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether. Or a functional group having a nitrogen atom with a lone electron pair that does not contribute to π conjugation. The nitrogen atom having a lone electron pair that does not contribute to π conjugation is, for example, a nitrogen atom having a partial structure represented by the following general formula.

Preferable partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine structure and the like.
Preferred examples of the partial structure of the ammonium group include tertiary ammonium, secondary ammonium, primary ammonium, pyridinium, imidazolinium, and pyrazinium structures.
The group containing such a structure preferably has 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group.
The alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, the alkyl group in the alkenyl group, the cycloalkyl group, the aryl group, the aralkyl group, and the alkenyl group, which contain a proton acceptor functional group or an ammonium group in R, are represented by Rx. These are the same as the alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group mentioned.

  Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C20) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 20). As for the aminoacyl group, examples of the substituent further include 1 or 2 alkyl groups (preferably having 1 to 20 carbon atoms).

When B is -N (Rx)-, R and Rx are preferably bonded to each other to form a ring. By forming the ring structure, the stability is improved, and the storage stability of the composition using the ring structure is improved. The number of carbon atoms forming the ring is preferably 4 to 20, and may be monocyclic or polycyclic, and may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the ring.
Examples of the monocyclic structure include a 4-membered ring, a 5-membered ring, a 6-membered ring, a 7-membered ring, and an 8-membered ring containing a nitrogen atom. Examples of the polycyclic structure include a structure composed of a combination of two or three or more monocyclic structures. The monocyclic structure and polycyclic structure may have a substituent, for example, a halogen atom, a hydroxyl group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), Aryl group (preferably having 6 to 14 carbon atoms), alkoxy group (preferably having 1 to 10 carbon atoms), acyl group (preferably having 2 to 15 carbon atoms), acyloxy group (preferably having 2 to 15 carbon atoms), alkoxycarbonyl A group (preferably having 2 to 15 carbon atoms), an aminoacyl group (preferably having 2 to 20 carbon atoms) and the like are preferable. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 15). As for the aminoacyl group, examples of the substituent include 1 or 2 alkyl groups (preferably having 1 to 15 carbon atoms).

  Among the compounds represented by the general formula (PA-I), a compound in which the Q site is a sulfonic acid can be synthesized by using a general sulfonamidation reaction. For example, a method in which one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine compound to form a sulfonamide bond, and then the other sulfonyl halide part is hydrolyzed, or a cyclic sulfonic acid anhydride is used. It can be obtained by a method of ring-opening by reacting with an amine compound.

  Hereinafter, although the specific example of a compound represented by general formula (PA-I) is shown, this invention is not limited to this.

  The compound represented by the following general formula (PA-II), which is generated by the decomposition of the compound (PA) upon irradiation with actinic rays or radiation and whose proton acceptor property is lowered, disappeared, or changed from proton acceptor property to acidity, ) Can be mentioned.

In general formula (PA-II),
Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either _one of Q ₁ and Q ₂ has a proton acceptor functional group. Q ₁ and Q ₂ may be bonded to each other to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —.

The monovalent organic groups as Q ₁ and Q _{2 in} formula (PA-II) preferably have 1 to 40 carbon atoms, and examples thereof include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, An alkenyl group etc. can be mentioned.
The alkyl group in Q ₁ and Q ₂ may have a substituent, preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and an oxygen atom, sulfur atom, nitrogen atom in the alkyl chain You may have. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.
The cycloalkyl group in Q ₁ and Q ₂ may have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and may have an oxygen atom or a nitrogen atom in the ring. Good. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Q ₁ and Q ₂ may have a substituent, and preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group and a naphthyl group.
The aralkyl group in Q ₁ and Q ₂ may have a substituent, and preferably an aralkyl group having 7 to 20 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, or a naphthylethyl group. Is mentioned.
The alkenyl group for Q ₁ and Q ₂ may have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group.
Examples of the substituent that each group may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group (preferably Has 6 to 14 carbon atoms, an alkoxy group (preferably 1 to 10 carbon atoms), an acyl group (preferably 2 to 20 carbon atoms), an acyloxy group (preferably 2 to 10 carbon atoms), an alkoxycarbonyl group (preferably C2-C20), an aminoacyl group (preferably C2-C10) etc. are mentioned. As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 10). Examples of the alkyl group having a substituent include perfluoroalkyl groups such as a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group.

One of the monovalent organic groups of Q ₁ and Q ₂ has a proton acceptor functional group.

  The proton acceptor functional group may be substituted with an organic group having a bond that is cleaved by an acid. Examples of the organic group having a bond that can be cleaved by an acid include an amide group, an ester group (preferably a tertiary alkyloxycarbonyl group), an acetal group (preferably a 1-alkyloxy-alkyloxy group), and a carbamoyl group. Group, carbonate group and the like.

Q ₁ and Q ₂ are bonded to each other to form a ring, and the formed ring has a proton acceptor functional group. For example, the organic group of Q ₁ and Q ₂ is further an alkylene group, an oxy And a structure bonded with a group, an imino group or the like.

In the general formula (PA-II), at least one of X ₁ and X ₂ is preferably —SO ₂ —.

  The compound represented by the general formula (PA-II) is preferably a compound represented by the following general formula (PA-III).

In general formula (PA-III),
Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ has a proton acceptor functional group. Q ₁ and Q ₃ may be bonded to each other to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may be bonded to each other to form a ring.
n represents 0 or 1.

Q ₁ has the same meaning as Q _{1 in} formula (PA-II).
Examples of the organic group of Q ₃ include the same organic groups as Q ₁ and Q ₂ in formula (PA-II).

  The divalent linking group in A is preferably a divalent linking group having 1 to 8 carbon atoms, for example, an alkylene group having 1 to 8 carbon atoms, a phenylene group having a fluorine atom. Etc. An alkylene group having a fluorine atom is more preferable, and a preferable carbon number is 2 to 6, more preferably 2 to 4. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, more preferably a perfluoroalkylene group, and particularly preferably a perfluoroethylene group, a perfluoropropylene group, or a perfluorobutylene group. .

  The monovalent organic group in Qx is preferably an organic group having 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Examples of the alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group are the same as those described above.

In the general formula (PA-III), X ₁ , X ₂ and X ₃ are preferably —SO ₂ —.

  Hereinafter, although the specific example of a compound represented by general formula (PA-II) is shown, this invention is not limited to this.

  As the compound (PA), a sulfonium salt compound of the compound represented by the general formula (PA-I), (PA-II) or (PA-III), the general formula (PA-I), (PA-II) or The iodonium salt compound of the compound represented by (PA-III) is preferable, and the compound represented by the following general formula (PA1) or (PA2) is more preferable.

In general formula (PA1):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (PA-I) is removed, or a general formula (PA-II) or (PA -III) represents an anion of the compound represented by

The carbon number of the organic group in R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
It is also possible to form the two members to ring structure of the R ₂₀₁ to R _203, an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Examples of the group formed by combining two of R _{201 to} R ₂₀₃ with each other include an alkylene group (eg, butylene group, pentylene group).
Specific examples of the organic group for R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (A1a), (A1b) and (A1c) described later.
In addition, the compound which has two or more structures represented by general formula (PA1) may be sufficient. For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by the general formula (PA1) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (PA1) It may be a compound.

  As more preferred (PA1) component, compounds (A1a), (A1b), and (A1c) described below can be exemplified.

Compound (A1a) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (PA1), 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, diarylcycloalkylsulfonium compounds, aryldialkylsulfonium compounds, aryldicycloalkylsulfonium compounds, arylalkylcycloalkylsulfonium compounds, and the like.
The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are 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 They are a C1-C4 alkyl group and a C1-C4 alkoxy group. The substituent may be substituted on any one of three R ₂₀₁ to R _203, or may be substituted on 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 (A1b) will be described.
The compound (A1b) is a compound in which R _{201 to} R ₂₀₃ in the general formula (PA1) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.
The organic group not having an aromatic ring in R ₂₀₁ to R _203, generally from 1 to 30 carbon atoms, preferably an organic group having 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, An alkoxycarbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.
The alkyl group in R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 20 carbon atoms (for example, a methyl group, an ethyl group,
Propyl group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, an alkoxycarbonylmethyl group are preferred.
Preferred examples of the cycloalkyl group for R _{201 to} R ₂₀₃ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable.
The linear or branched 2-oxoalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably has> C═O at the 2-position of the alkyl group. The group can be mentioned.
The 2-oxocycloalkyl group in R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably includes a group having> C═O at the 2-position of the cycloalkyl group. be able to.
The alkoxy group in the alkoxycarbonylmethyl group of R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), an alkoxycarbonyl group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. .

  The compound (A1c) is a compound represented by the following general formula (A1c), and is a compound having an arylacylsulfonium salt structure.

In general formula (A1c):
_R213 represents an aryl group which may have a substituent, and is preferably a phenyl group or a naphthyl group. Preferred substituents in R _213, an alkyl group, an alkoxy group, an acyl group, a nitro group, a hydroxyl group, an alkoxycarbonyl group and a carboxy group.
R ₂₁₄ and R ₂₁₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Y ₂₀₁ and Y ₂₀₂ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or a vinyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (PA-I) is removed, or a general formula (PA-II) or (PA -III) represents an anion of the compound represented by
R ₂₁₃ and R ₂₁₄ may be bonded to each other to form a ring structure, R ₂₁₄ and R ₂₁₅ may be bonded to each other to form a ring structure, and Y ₂₀₁ and Y ₂₀₂ are respectively They may be bonded to each other to form a ring structure. These ring structures may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond. Examples of the group formed by combining R ₂₁₃ and R ₂₁₄ , R ₂₁₄ and R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ with each other include a butylene group and a pentylene group.

As the alkyl group for R ₂₁₄ , R ₂₁₅ , Y _201, and Y ₂₀₂ , a linear or branched alkyl group having 1 to 20 carbon atoms is preferable. Examples of the alkyl group for Y ₂₀₁ and Y ₂₀₂ include a 2-oxoalkyl group having> C═O at the 2-position of the alkyl group, an alkoxycarbonylalkyl group (preferably an alkoxy group having 2 to 20 carbon atoms), and a carboxyalkyl group. More preferred.
The cycloalkyl group for R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a cycloalkyl group having 3 to 20 carbon atoms.

Y ₂₀₁ and Y ₂₀₂ are preferably an alkyl group having 4 or more carbon atoms, more preferably an alkyl group having 4 to 6, and further preferably 4 to 12.
In addition, at least one of R ₂₁₄ or R ₂₁₅ is preferably an alkyl group, and more preferably both R ₂₁₄ and R ₂₁₅ are alkyl groups.

In the general formula (PA2),
_R204 and _R205 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X ⁻ represents a sulfonate anion or carboxylate anion from which a hydrogen atom of the —SO ₃ H site or —COOH site of the compound represented by the general formula (PA-I) is removed, or a general formula (PA-II) or (PA -III) represents an anion of the compound represented by

The aryl group of R ₂₀₄ and R _205, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group in R ₂₀₄ and R ₂₀₅ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).
Preferred examples of the cycloalkyl group for R ₂₀₄ and R ₂₀₅ include cycloalkyl groups having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group, norbornyl group).
_R204 and _R205 may have a substituent. Examples of the substituent that R ₂₀₄ and R ₂₀₅ may have include, 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 (for example, 6 to 6 carbon atoms). 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

  The compound that generates the compound represented by the general formula (PA-I), (PA-II), or (PA-III) upon irradiation with actinic rays or radiation is preferably represented by the general formula (PA1). A compound, more preferably compounds (A1a) to (A1c).

Compound (PA) decomposes upon irradiation with actinic rays or radiation to generate, for example, a compound represented by general formula (PA-1) or (PA-2).
The compound represented by the general formula (PA-1) has a sulfo group or a carboxyl group together with a proton acceptor functional group, so that the proton acceptor property is reduced or disappeared compared to the compound (PA), or the proton acceptor. It is a compound that has changed from scepter to acidic.
The compound represented by the general formula (PA-2) has an organic sulfonylimino group or an organic carbonylimino group together with a proton acceptor functional group, so that the proton acceptor property decreases and disappears compared to the compound (PA). Or a compound that is changed from proton acceptor property to acidity.
In the present invention, the acceptor property is lowered when the non-covalent complex that is a proton adduct is formed from a compound having a proton acceptor functional group and a proton, and the equilibrium constant in the chemical equilibrium is reduced. Means.
Proton acceptor property can be confirmed by measuring pH.

  Hereinafter, although the specific example of the compound (PA) which generate | occur | produces the compound represented with general formula (PA-I) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

  These compounds are synthesized from a compound represented by the general formula (PA-I) or a lithium, sodium or potassium salt thereof and a hydroxide, bromide or chloride of iodonium or sulfonium. Or a salt exchange method described in JP-A No. 2003-246786.

  Hereinafter, although the specific example of the compound (PA) which generate | occur | produces the compound represented by general formula (PA-II) by irradiation of actinic light or a radiation is given, this invention is not limited to this.

These compounds can be easily synthesized by using a general sulfonic acid esterification reaction or sulfonamidation reaction. For example, one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine or alcohol containing a partial structure represented by the general formula (PA-II) to form a sulfonamide bond or a sulfonate bond Then, the other sulfonyl halide moiety can be hydrolyzed, or the cyclic sulfonic acid anhydride can be opened by an amine or alcohol containing a partial structure represented by the general formula (PA-II). . An amine or alcohol containing a partial structure represented by the general formula (PA-II) is an amine, an alcohol such as (R′O ₂ C) ₂ O or an anhydride such as R′O ₂ CCl, acid It can be synthesized by reacting with a chloride compound.

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

[4] Organic basic compound (C)
The organic basic compound contained in the resist composition of the present invention is preferably a compound having a stronger basicity than phenol. The molecular weight of the organic basic compound is usually 100 to 900, preferably 150 to 800, more preferably 200 to 700. Further, nitrogen-containing basic compounds are particularly preferable.

  Preferred nitrogen-containing basic compounds are compounds having structures of the following formulas (A) to (E) as a preferred chemical environment. Formulas (B) to (E) may be part of a ring structure.

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group. (Preferably having 6 to 20 carbon atoms), wherein R ²⁵¹ and R ²⁵² may be bonded to each other to form a ring.

  The alkyl group may be unsubstituted or may have a substituent. Examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 6 carbon atoms and a hydroxyalkyl group having 1 to 6 carbon atoms. preferable.

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.

  Further, at least one nitrogen-containing compound selected from an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group can be exemplified. .

As the amine compound, a primary, secondary or tertiary amine compound can be used, and an amine compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. The amine compound is more preferably a tertiary amine compound. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the amine compound has an cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (preferably having 3 to 20 carbon atoms). Preferably C6-C12) may be bonded to a nitrogen atom. The amine compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

As the ammonium salt compound, a primary, secondary, tertiary, or quaternary ammonium salt compound can be used, and an ammonium salt compound in which at least one alkyl group is bonded to a nitrogen atom is preferable. As long as at least one alkyl group (preferably having 1 to 20 carbon atoms) is bonded to a nitrogen atom, the ammonium salt compound has a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group in addition to the alkyl group. (Preferably having 6 to 12 carbon atoms) may be bonded to a nitrogen atom. The ammonium salt compound preferably has an oxygen atom in the alkyl chain and an oxyalkylene group is formed. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group. Examples of the anion of the ammonium salt compound include halogen atoms, sulfonates, borates, and phosphates. Among them, halogen atoms and sulfonates are preferable. As the halogen atom, chloride, bromide, and iodide are particularly preferable. As the sulfonate, an organic sulfonate having 1 to 20 carbon atoms is particularly preferable. Examples of the organic sulfonate include alkyl sulfonates having 1 to 20 carbon atoms and aryl sulfonates. The alkyl group of the alkyl sulfonate may have a substituent, and examples of the substituent include fluorine, chlorine, bromine, alkoxy groups, acyl groups, and aryl groups. Specific examples of the alkyl sulfonate include methane sulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzyl sulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, and nonafluorobutane sulfonate. Examples of the aryl group of the aryl sulfonate include a benzene ring, a naphthalene ring, and an anthracene ring. The benzene ring, naphthalene ring and anthracene ring may have a substituent, and the substituent is preferably a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the linear or branched alkyl group and cycloalkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl and the like. Examples of the other substituent include an alkoxy group having 1 to 6 carbon atoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxy group.

  The amine compound having a phenoxy group and the ammonium salt compound having a phenoxy group are those having a phenoxy group at the terminal opposite to the nitrogen atom of the alkyl group of the amine compound or ammonium salt compound. The phenoxy group may have a substituent. Examples of the substituent of the phenoxy group include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, a sulfonic acid ester group, an aryl group, an aralkyl group, an acyloxy group, and an aryloxy group. Etc. The substitution position of the substituent may be any of the 2-6 positions. The number of substituents may be any in the range of 1 to 5.

It is preferable to have at least one oxyalkylene group between the phenoxy group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  In the amine compound having a sulfonic acid ester group and the ammonium salt compound having a sulfonic acid ester group, the sulfonic acid ester group may be any of alkyl sulfonic acid ester, cycloalkyl group sulfonic acid ester, and aryl sulfonic acid ester. In the case of an alkyl sulfonate ester, the alkyl group has 1 to 20 carbon atoms, in the case of a cycloalkyl sulfonate ester, the cycloalkyl group has 3 to 20 carbon atoms, and in the case of an aryl sulfonate ester, the aryl group has 6 carbon atoms. ~ 12 are preferred. Alkyl sulfonic acid ester, cycloalkyl sulfonic acid ester, and aryl sulfonic acid ester may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, a carboxyl group, a carboxylic acid ester group, and a sulfonic acid. An ester group is preferred.

It is preferable to have at least one oxyalkylene group between the sulfonate group and the nitrogen atom. The number of oxyalkylene groups is one or more in the molecule, preferably 3 to 9, and more preferably 4 to 6. Among the oxyalkylene groups, an oxyethylene group (—CH ₂ CH ₂ O—) or an oxypropylene group (—CH (CH ₃ ) CH ₂ O— or —CH ₂ CH ₂ CH ₂ O—) is preferable, and more preferably oxy Ethylene group.

  Preferred examples include guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, imidazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and the like. These may have a substituent, and preferred substituents include 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 and the like.

  Particularly preferred compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4 , 5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4- Aminoethylpyridine, 3-aminopyrrolidine, Perazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, Examples include, but are not limited to, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine. It is not a thing.

  A tetraalkylammonium salt type nitrogen-containing basic compound can also be used. Of these, tetraalkylammonium hydroxide having 1 to 8 carbon atoms (tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra- (n-butyl) ammonium hydroxide, etc.) is particularly preferable. These nitrogen-containing basic compounds are used alone or in combination of two or more.

  The use ratio of the acid generator and the organic basic compound in the composition is preferably acid generator / organic basic compound (molar ratio) = 1.0 to 300. That is, the molar ratio is preferably 1.0 or more from the viewpoints of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / organic basic compound (molar ratio) is more preferably 1.5 to 200, still more preferably 2.0 to 150.

[5] Surfactants In the present invention, surfactants can be used, which are preferable from the viewpoints of film forming properties, pattern adhesion, development defect reduction, and the like.

  Specific examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene Polyoxyethylene alkyl allyl ethers such as nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Sorbitan fatty acid esters such as rate, polyoxyethylene sorbitan monolaurate, polyoxyethylene Sorbitan mono palmitate - door,

Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, F-top EF301, EF303, EF352 (Shin-Akita Kasei) (Made by Co., Ltd.), MegaFuck F171, F173 (Dainippon Ink Chemical Co., Ltd.), Florad FC430, FC431 (Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC101, SC102 , SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical Co., Ltd.) and the like, or silicon-based surfactants, organosiloxane polymer KP341 Shin-Etsu Chemical Co., Ltd.) and acrylic or methacrylic acid-based (co) polymer Polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.). The compounding amount of these surfactants is usually 2 parts by mass or less, preferably 1 part by mass or less per 100 parts by mass of the solid content in the composition of the present invention.
These surfactants may be added alone or in some combination.

The surfactant is any one of fluorine and / or silicon surfactants (fluorine surfactants and silicon surfactants, surfactants containing both fluorine atoms and silicon atoms), or It is preferable to contain 2 or more types.
As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), PF6320 Fluorosurfactants such as (manufactured by OMNOVA) or silicon surfactants 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). It may be 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. 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 the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition (excluding the solvent).

[6] Other components The positive resist composition of the present invention may further contain a dye, a photobase generator and the like, if necessary.

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

2. Photobase generator As photobase generators that can be added to the composition of the present invention, JP-A-4-151156, JP-A-4-162040, JP-A-5-197148, JP-A-5-5995, JP-A-6-194835, Examples thereof include compounds described in JP-A-8-146608, JP-A-10-83079 and European Patent No. 622682, specifically, 2-nitrobenzylcarbamate, 2,5-dinitrobenzylcyclohexylcarbamate, N-cyclohexyl-4- Methylphenylsulfonamide, 1,1-dimethyl-2-phenylethyl-N-isopropylcarbamate and the like can be suitably used. These photobase generators are added for the purpose of improving the resist shape and the like.

3. Antioxidant An antioxidant may be used as an additive.
The antioxidant is for preventing the organic material from being oxidized in the presence of oxygen. The antioxidant is not particularly limited as long as it is effective in preventing the oxidation of commonly used plastics, for example, a phenolic antioxidant, an antioxidant made of an organic acid derivative, and a sulfur-containing agent. Antioxidants, phosphorus antioxidants, amine antioxidants, antioxidants composed of amine-aldehyde condensates, antioxidants composed of amine-ketone condensates, and the like. Of these antioxidants, a phenolic antioxidant as an antioxidant and an antioxidant composed of an organic acid derivative are used to exhibit the effects of the present invention without deteriorating the function of the resist. It is preferable.
Here, as the phenolic antioxidant, substituted phenols such as 1-oxy-3-methyl-4-isopropylbenzene, 2,6-di-tert-butylphenol, 2,6-di-tert- Butyl-4-ethylphenol, 2,6-di-tert-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-tert-butylphenol, butyl hydroxyanisole, 2- (1-methyl (Cyclohexyl) -4,6-dimethylphenol, 2,4-dimethyl-6-tert-butylphenol, 2-methyl-4,6-dinonylphenol, 2,6-di-tert-butyl-α-dimethylamino- p-cresol, 6- (4-hydroxy-3,5-di-tert-butylanilino) 2,4-bisoctyl-thio-1,3,5-triazine, n-octyl Examples include decyl-3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl) propionate, octylated phenol, aralkyl-substituted phenols, alkylated p-cresol, hindered phenol and the like. Bis, tris, polyphenols such as 4,4′-dihydroxy diphenyl, methylene bis (dimethyl-4,6-phenol), 2,2′-methylene-bis- (4-methyl-6-tert. -Butylphenol), 2,2'-methylene-bis- (4-methyl-6-cyclohexyl phenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4 '-Methylene-bis- (2,6-di-tert-butylphenol), 2,2'-methylene-bis- (6-alphamethyl-benzyl-p-cresol ), Methylene-bridged polyhydric alkylphenol, 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2′-dihydroxy -3,3'-di- (α-methylcyclohexyl) -5,5'-dimethyl diphenylmethane, alkylated bisphenol, hindered bisphenol, 1,3,5-trimethyl-2,4,6-tris (3 5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, tetrakis- [methylene-3- (3 ′, 5 ′ -Di-tert-butyl-4'-hydroxyphenyl) propionate] methane and the like.
Preferable specific examples of the antioxidant used in the present invention include 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, and 2,2′-methylenebis. (4-methyl-6-tert-butylphenol), butylhydroxyanisole, t-butylhydroquinone, 2,4,5-trihydroxybutyrophenone, nordihydroguaiaretic acid, propyl gallate, octyl gallate, lauryl gallate, And isopropyl citrate. Of these, 2,6-di-t-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-t-butylphenol, butylhydroxyanisole, and t-butylhydroquinone are preferred, and 2,6-diethyl is further preferred. -T-Butyl-4-methylphenol or 4-hydroxymethyl-2,6-di-t-butylphenol is more preferred.
When the antioxidant is used, the content in the positive resist composition of the present invention is preferably 1 ppm or more, more preferably 5 ppm or more, further preferably 10 ppm or more, even more preferably 50 ppm or more, particularly Preferably it is 100 ppm or more, Most preferably, it is 100-1000 ppm. One type of antioxidant may be used, or two or more types may be mixed.

4). Solvents The resist composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. The solid content concentration of all resist components is usually preferably 2 to 30% by mass, more preferably 3 to 25% by mass.
Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.
In particular, a solvent containing propylene glycol monomethyl ether acetate is preferably used, and a mixed solvent containing propylene glycol monomethyl ether is more preferably used.

  The 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 0.05 to 4.0 μm.

  The composition of the present invention is excellent in that the generation of a standing wave is remarkably suppressed and a good pattern can be obtained even when it is directly applied to a substrate having a highly reflective surface without applying an antireflection film. Although effective, a good pattern can be formed even if an antireflection film is used.

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

In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.
Further, if necessary, an antireflection film can be used as an upper layer of the resist.
Examples of the antireflection film include AQUATAR-II, AQUATAR-III, and AQUATAR-VII manufactured by AZ Electronic Materials.

  In the manufacture of precision integrated circuit elements, the pattern forming process on the resist film is carried out on the substrate (eg, silicon / silicon dioxide coated substrate, glass substrate, ITO substrate, quartz / chromium oxide coated substrate, etc.). A resist pattern is formed by applying a resist composition, forming a resist film, and then irradiating actinic rays or radiation such as KrF excimer laser light, electron beam, EUV light, etc., heating, developing, rinsing and drying. Can be formed.

Examples of the alkaline developer used in development include inorganic alkalis 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, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, An aqueous solution (usually 0.1 to 20% by mass) of an alkali such as a quaternary ammonium salt such as choline or a cyclic amine such as pyrrole or piperidine can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.
Among these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.
The pH of the alkali developer is usually 10-15.

  Examples of the actinic ray or radiation serving as the exposure light source include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly Preferably, far ultraviolet light having a wavelength of 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), X-ray, electron beam, EUV, etc., KrF The exposure is preferably performed by irradiation with an electron beam, X-rays or EUV.

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

(Synthesis Example 1) Synthesis of polymer (A-1) 31.63 g (0.195 mol) of 4-acetoxystyrene, 13.65 g (0.096 mol) of t-butyl methacrylate, 2.14 g of (4-phenyl) phenyl methacrylate 0.009 mol) and 3.45 g (0.015 mol) of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) were dissolved in 151.75 g of cyclohexanone. In a reaction vessel, 37.94 g of cyclohexanone was placed and added dropwise to the system at 80 ° C. over 6 hours under a nitrogen gas atmosphere. After dropping, the reaction solution was allowed to cool to room temperature after being heated and stirred for 2 hours, dropped into 2.5 L of hexane to precipitate a polymer, and filtered. The filtered solid was filtered with 500 mL of hexane, and the filtered solid was dried under reduced pressure to obtain 42.68 g of 4-acetoxystyrene / t-butyl methacrylate / (4-phenyl) phenyl methacrylate copolymer.

  In a reaction vessel, 40.00 g of the polymer obtained above was dissolved in 92 mL of ethyl acetate and 92 mL of methanol, 39.05 g of a 28% methanol solution of sodium methoxide was added and stirred for 3 hours, and hydrochloric acid was added. Acidified. Ethyl acetate 500mL was added and it wash | cleaned 5 times with distilled water 200mL. The organic layer was taken out and concentrated, dissolved in 150 mL of methanol, and dropped into 1.5 L of distilled water / methanol = 7/3 to precipitate a polymer, followed by filtration. The solid filtered with 500 mL of distilled water / methanol = 7/3 was washed, and the filtered solid was dried under reduced pressure to obtain 4-hydroxystyrene / t-butyl methacrylate / (4-phenyl) phenyl methacrylate copolymer. 29.77 g was obtained. The weight average molecular weight by GPC was 8000, and the molecular weight dispersity (Mw / Mn) was 1.47.

  In addition, when acetalization is required like the polymers (A-59), (A-60), and (A-61), the following steps are performed.

(Synthesis Example 2) Synthesis of Polymer (A-60) In a reaction vessel, 20.00 g of the above polymer (A-1) was dissolved in 300 g of PGMEA, and this solution was decompressed to 60 mm and 20 mmHg, and about 150 g of solvent. Was distilled off with water remaining in the system, cooled to 20 ° C., 1.32 g of ethyl vinyl ether and 5.6 mg of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 2 hours. Thereafter, 0.06 g of triethylamine was added for neutralization, and 300 g of ethyl acetate and 100 g of water were added for washing operation three times. Thereafter, the amount of the solvent was adjusted to obtain a 30% by mass polymer solution. The weight average molecular weight by GPC was 8100, the molecular weight dispersity was 1.47, and from 1H and 13C-NMR analysis, the acetal protection rate of phenolic OH was 10%.

  Resins whose structures were previously exemplified as shown in Table 1 were synthesized in the same manner as in Synthesis Examples 1 and 2 except that the monomers and vinyl ethers used were changed. The composition ratio (molar ratio) is the order of repeating units from the left in the resin structure exemplified above with the symbols shown in Table 1.

(Preparation of resist composition)
Resins, acid generators, proton acceptor-containing compounds, surfactants, and basic compounds shown in Tables 2 and 3 are dissolved in propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether in the following addition amounts to form solids. After preparing a solution having a partial concentration of 5.0% by mass, the obtained solution was microfiltered with a membrane filter having a 0.1 μm aperture to obtain a resist composition.

<Preparation of resist composition>
Resin: 17.1653g
Acid generator: 0.1479 g
Basic compound (or proton acceptor group-containing compound): 0.0393 g (0.0196 g each when a proton acceptor group-containing compound and a basic compound are used in combination)
Surfactant: 0.4020 g

[Pattern preparation and evaluation (KrF)
Using a spin coater, the positive resist solution prepared as described above is uniformly coated on a silicon wafer that has been subjected to hexamethyldisilazane treatment, and is heated and dried at 120 ° C. for 90 seconds to form a positive film having a thickness of 0.4 μm. A mold resist film was formed. The resist film was subjected to pattern exposure using a KrF excimer laser stepper (FPA3000EX-5 manufactured by Canon Inc., wavelength 248 nm). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.

  Resist performance was evaluated as follows. The results are shown in Table 2.

[Remaining standing waves]
The side wall of the resist pattern obtained with a 0.30 μm line and space mask pattern was observed with a scanning electron microscope, and the following five-step evaluation was performed.
A: When there is no standing wave and the side wall of the pattern is very clean B: When the standing wave is slightly seen or irregularities are seen on the side wall of the pattern C: When the standing wave can be clearly confirmed (this implementation) Not applicable in the example)
D: When the standing wave can be confirmed slightly strongly E: When the standing wave can be confirmed very strongly

[Profile]
The profile of the pattern obtained above was observed with a cross-sectional SEM, and the following three-stage evaluation was performed.
1: When the shape is rectangular 2: When the taper is almost not recognized, the shape is almost rectangular 3: When the shape is clearly tapered

〔sensitivity〕
Scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.) was used for the cross-sectional shape of the obtained pattern.
Was observed. The minimum irradiation energy when resolving a 180 nm line (line: space = 1: 1) was defined as sensitivity.

[Resolution]
The resolving power was defined as the limiting resolving power (line and space were separated and resolving) at the irradiation dose showing the above sensitivity.

The component (c) used in the examples, other components, and resins used in the comparative examples are shown below.
[Organic basic compounds]
D-1: Dicyclohexylmethylamine D-2: 2,4,6-triphenylimidazole D-3: Tetra- (n-butyl) ammonium hydroxide

[Other components (surfactant)]
W-1: Fluorosurfactant, PF6320 (manufactured by OMNOVA)
W-2: Fluorine / silicone surfactant, MegaFac R08 (manufactured by Dainippon Ink & Chemicals, Inc.)
W-3: Silicon-based surfactant, siloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  Molar composition ratio 65/35 Weight average molecular weight 12000 Dispersity 1.55

Molar composition ratio 60/40 Weight average molecular weight 8500 Dispersity 1.20

  From the results in Table 2, the resist composition of the present invention is superior to the case where the compound of the comparative example is used in each of standing wave, profile, sensitivity, and resolving power without using an antireflection film in the lower layer. It can be seen that it is suitable for implantation.

Claims (10)

(A) a resin having a structure represented by the general formula (I) and containing a repeating unit having absorption at a wavelength of 248 nm and having increased solubility in an alkaline developer by the action of an acid; Alternatively, a positive resist composition comprising a compound that generates an acid upon irradiation with radiation.
In formula (I),
Ra and Rb are each independently a hydrogen atom, alkyl group, hydroxyl group, alkoxy group, halogen atom, cyano group, nitro group, acyl group, acyloxy group, cycloalkyl group, aryl group, carboxyl group, alkyloxycarbonyl group Represents an alkylcarbonyloxy group or an aralkyl group.
Z ¹ represents a non-acid-decomposable group. When a plurality of Z ¹ are present, they may be connected to each other to form a ring.
Y represents a single bond or a linking group.
m represents 1 or 2. 2. The positive resist composition according to claim 1, wherein the repeating unit represented by the general formula (I) is a repeating unit represented by the formula (Ia).
In formula (Ia),
Ra represents a hydrogen atom or a methyl group.
Z ¹ represents a non-acid-decomposable group. 2. The positive resist composition according to claim 1, wherein the repeating unit represented by the general formula (I) is a repeating unit represented by the formula (Ib).
In formula (Ib),
Ra represents a hydrogen atom or a methyl group.
Z ¹ each independently represents a non-acid-decomposable group. Z ¹ may be bonded to each other to form a ring. In the repeating unit represented by the general formula (I), Z ¹ is a group containing a group having one or more benzene rings and absorbing at a wavelength of 248 nm. The positive resist composition according to any one of the above. In the repeating unit represented by the general formula (I), Z ¹ is a group containing a group having two or more benzene rings and having absorption at a wavelength of 248 nm. The positive resist composition according to any one of the above. In the repeating unit represented by the general formula (I), Z ¹ is a group containing a group having 3 or more benzene rings and absorbing at a wavelength of 248 nm. The positive resist composition according to any one of the above. The resin containing the repeating unit represented by the general formula (I) further contains at least one repeating unit represented by the general formula (A1) or (A2). The positive resist composition according to any one of the above.

In general formula (A1),
n shows the integer of 0-5. m shows the integer of 0-5. However, m + n ≦ 5.
A ₁ represents a hydrogen atom or a group containing a group that decomposes under the action of an acid, and when there are a plurality of groups, they may be the same or different.
S ₁ represents an arbitrary substituent, and when there are a plurality of S _{1 s} , they may be the same or different.
In the general formula (A2), X represents a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, an acyl group, an acyloxy group, a cycloalkyl group, an aryl group, a carboxyl group, an alkyloxycarbonyl group. Represents an alkylcarbonyloxy group or an aralkyl group.
A ₂ represents a group containing a group that decomposes by the action of an acid.   (B) The positive resist composition according to claim 1, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is oxime sulfonate or diazodisulfone.   Furthermore, it contains a compound that has a proton acceptor functional group and generates a compound that is decomposed by irradiation with actinic rays or radiation to decrease, disappear, or change the proton acceptor property to acidic. The positive resist composition according to claim 1, wherein the positive resist composition is a positive resist composition.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1, exposing and developing the resist film.