JP4682026B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photo-publishing processes, and a pattern forming method using the same. More particularly, the present invention relates to a positive resist capable of forming a high-definition pattern using KrF excimer laser light, electron beam, EUV light, and the like, and a pattern forming method using the same. KrF excimer laser light, electron beam The present invention relates to a positive resist composition that can be suitably used for microfabrication of a semiconductor element using EUV light, and a pattern forming method using the same.

  Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a resist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Accordingly, there is a tendency for the exposure wavelength to be shortened from g-line to i-line, and further to KrF excimer laser light. Furthermore, at present, in addition to excimer laser light, lithography using electron beams, X-rays, or EUV light is also being developed.

  Lithography using an electron beam or EUV light is positioned as a next-generation or next-generation pattern forming technology, and a positive resist with high sensitivity and high resolution is desired. In particular, high sensitivity is a very important issue for shortening the wafer processing time. However, in positive resists for electron beams and EUV, if high sensitivity is to be pursued, not only the resolution will be lowered. As a result, the line edge roughness deteriorates, and it is strongly desired to develop a resist that satisfies these characteristics simultaneously. Here, the line edge roughness means that when the pattern is viewed from directly above because the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. Say that the edge looks uneven. The unevenness is transferred by an etching process using a resist as a mask, and the electrical characteristics are deteriorated, so that the yield is lowered. Particularly in the ultrafine region of 0.25 μm or less, the line edge roughness is an extremely important improvement issue. High sensitivity, high resolution, and good line edge roughness are in a trade-off relationship, and it is very important how to satisfy them simultaneously.

Further, in lithography using KrF excimer laser light, it is also important to satisfy high sensitivity, high resolution, and good line edge roughness at the same time, and these solutions are necessary.
As a resist suitable for the lithography process using KrF excimer laser light, electron beam, or EUV light, a chemically amplified resist utilizing an acid-catalyzed reaction is mainly used from the viewpoint of high sensitivity. In the resist, as a main component, a phenolic polymer (hereinafter abbreviated as a phenolic acid-decomposable resin) that is insoluble or hardly soluble in an alkaline aqueous solution and becomes soluble in an alkaline aqueous solution by the action of an acid, and acid generation A chemically amplified resist composition comprising an agent is effectively used.

For these positive resists, compounds that generate sulfonic acid upon irradiation with actinic rays or radiation using a phenolic acid-decomposable resin copolymerized with an acid-decomposable acrylate monomer (hereinafter abbreviated as sulfonic acid generator) Several resist compositions containing are known. For example, positive resist compositions disclosed in Patent Documents 1 to 5 can be exemplified.
However, in any combination of these, at present, high sensitivity, high resolution, and good line edge roughness are not satisfied at the same time in the ultrafine region.

US Pat. No. 5,561,194 JP 2001-166474 A JP 2001-166478 A JP 2003-107708 A JP 2001-194792 A

  The object of the present invention is to solve the problem of performance improvement technology in microfabrication of semiconductor elements using actinic rays or radiation, particularly KrF excimer laser light, electron beam or EUV light, and has high sensitivity and high resolution. Another object of the present invention is to provide a positive resist composition satisfying both good line edge roughness and good dissolution contrast and a pattern forming method using the same.

一般式（１）において、
Ｒ ₁ は、水素原子、メチル基、シアノ基、ハロゲン原子又は炭素数１〜４のペルフルオロアルキル基を表す。
Ｒ ₂ 及びＲ ₃ は、各々独立に、アルキル基を表す。
Ｘは、脂環式基を表す。
一般式（２）において、
Ｒ ₄ は、水素原子、メチル基、シアノ基、ハロゲン原子又は炭素数１〜４のペルフルオロアルキル基を表す。
Ｒ ₅ は、アルキル基、ハロゲン原子、アリール基、アルコキシ基又はアシル基を表す。
ｌは、０〜４の整数を表す。
一般式（３）において、
Ｒ ₆ は、水素原子、メチル基、シアノ基、ハロゲン原子又は炭素数１〜４のペルフルオロアルキル基を表す。
Ｒ ₇ は、アルキル基、ハロゲン原子、アリール基、アルコキシ基又はアシル基を表す。
Ｒ ₈ は、アルキル基、脂環式基、アリール基又はヘテロ環基を表す。
ｍは、０〜４の整数を表す。
ｎは、１〜５の整数を表す。
＜２＞ 樹脂（Ａ）が、一般式（１）で表される繰り返し単位を５〜８０モル％、一般式（２）で表される繰り返し単位を５〜９０モル％、一般式（３）で表される繰り返し単位を１０〜９０モル％有することを特徴とする上記＜１＞に記載のポジ型レジスト組成物。
＜３＞ 更に、活性光線又は放射線の照射により酸を発生する酸発生剤（Ｂ）を含有し、且つ酸発生剤（Ｂ）の含有量が、ポジ型レジスト組成物の全固形分に対し５〜２０質量％であることを特徴とする上記＜１＞又は＜２＞に記載のポジ型レジスト組成物。
＜４＞ 一般式（１）における、Ｘが、有橋脂環式基であることを特徴とする上記＜１＞〜＜３＞のいずれかに記載のポジ型レジスト組成物。
＜５＞ 一般式（１）における、Ｘが、アダマンチル基であることを特徴とする上記＜４＞に記載のポジ型レジスト組成物。
＜６＞ 上記＜１＞〜＜５＞のいずれかに記載のポジ型レジスト組成物から形成されたレジスト膜。
＜７＞ 上記＜６＞に記載のレジスト膜に対して、露光、現像を行うことを特徴とするパターン形成方法。
本発明は、上記＜１＞〜＜７＞に係る発明であるが、以下、参考のため、他の事項も含めて記載している。 As a result of intensive studies, the present inventors have found that the object of the present invention is achieved by the following resist composition.
<1> An alkaline developer comprising only a repeating unit represented by the following general formula (1), a repeating unit represented by the following general formula (2), and a repeating unit represented by the following general formula (3) A positive resist composition comprising a resin (A) which is insoluble or hardly soluble and has a property of being soluble in an alkali developer by the action of an acid.

In general formula (1),
R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₂ and R ₃ each independently represents an alkyl group.
X represents an alicyclic group.
In general formula (2),
R ₄ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group having 1 to 4 carbon atoms.
R ₅ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
l represents an integer of 0 to 4.
In general formula (3),
R ₆ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₇ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
R ₈ represents an alkyl group, an alicyclic group, an aryl group, or a heterocyclic group.
m represents an integer of 0 to 4.
n represents an integer of 1 to 5.
<2> The resin (A) contains 5 to 80 mol% of the repeating unit represented by the general formula (1), 5 to 90 mol% of the repeating unit represented by the general formula (2), and the general formula (3). The positive resist composition as described in <1> above, having 10 to 90 mol% of the repeating unit represented by formula (1).
<3> Furthermore, it contains an acid generator (B) that generates an acid upon irradiation with actinic rays or radiation, and the content of the acid generator (B) is 5 with respect to the total solid content of the positive resist composition. The positive resist composition as described in <1> or <2> above, which is ˜20% by mass.
<4> The positive resist composition as described in any one of <1> to <3>, wherein X in the general formula (1) is a bridged alicyclic group.
<5> The positive resist composition as described in <4> above, wherein X in the general formula (1) is an adamantyl group.
<6> A resist film formed from the positive resist composition according to any one of <1> to <5>.
<7> A pattern forming method comprising exposing and developing the resist film according to <6>.
The present invention is an invention according to the above <1> to <7>, but is described below including other matters for reference.

  (1) An alkaline developer having a repeating unit represented by the following general formula (1), a repeating unit represented by the following general formula (2), and a repeating unit represented by the following general formula (3) A positive resist composition comprising a resin (A) which is insoluble or hardly soluble and has a property of being soluble in an alkali developer by the action of an acid.

In general formula (1),
R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₂ and R ₃ each independently represents an alkyl group.
X represents an alicyclic group.
In general formula (2),
R ₄ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group having 1 to 4 carbon atoms.
R ₅ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
l represents an integer of 0 to 4.
In general formula (3),
R ₆ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₇ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
R ₈ represents an alkyl group, an alicyclic group, an aryl group, or a heterocyclic group.
m represents an integer of 0 to 4.
n represents an integer of 1 to 5.

  (2) The resin (A) contains 5 to 80 mol% of the repeating unit represented by the general formula (1), 5 to 90 mol% of the repeating unit represented by the general formula (2), and the general formula (3). The positive resist composition as described in (1), wherein 10 to 90 mol% of the repeating unit represented by formula (1) is contained.

  (3) Further, it contains an acid generator (B) that generates an acid upon irradiation with actinic rays or radiation, and the content of the acid generator (B) is 5 with respect to the total solid content of the positive resist composition. The positive resist composition as described in (1) or (2), which is ˜20% by mass.

  (4) The positive resist composition as described in any one of (1) to (3), wherein X in the general formula (1) is a bridged alicyclic group.

  (5) The positive resist composition as described in (4), wherein X in the general formula (1) is an adamantyl group.

  (6) A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of (1) to (5); and performing exposure and development.

  According to the present invention, it is possible to provide a positive resist composition excellent in sensitivity and resolution, and further excellent in line edge roughness and dissolution contrast, and an excellent pattern forming method.

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

[1] Resin (A) that is insoluble or hardly soluble in an alkali developer and becomes soluble in an alkali developer by the action of an acid
The resin (A) that is insoluble or hardly soluble in the alkali developer used in the present invention and has a property that becomes soluble in the alkali developer by the action of an acid is a repeating unit represented by the following general formula (1). And a repeating unit represented by the following general formula (2) and a repeating unit represented by the following general formula (3).

In general formula (1),
R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₂ and R ₃ each independently represents an alkyl group.
X represents an alicyclic group.
In general formula (2),
R ₄ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group having 1 to 4 carbon atoms.
R ₅ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
l represents an integer of 0 to 4.
In general formula (3),
R ₆ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₇ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
R ₈ represents an alkyl group, an alicyclic group, an aryl group, or a heterocyclic group.
m represents an integer of 0 to 4.
n represents an integer of 1 to 5.

In the general formula (1), R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a C _{1 to} C 4 perfluoroalkyl group (C _m F _{2m + 1} group, and m represents ₁ to 4). Represents an integer). R ₁ is preferably a hydrogen atom, a methyl group, or a C _m F _{2m + 1} group (m is preferably 1), and particularly preferably a hydrogen atom or a methyl group.

R ₂ and R ₃ each independently represents an alkyl group which may have a substituent, preferably an alkyl group having 1 to 16 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, particularly Preferably, it is a C1-C8 alkyl group (methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, etc.).
Examples of substituents include hydroxy groups, carboxyl groups, halogen atoms (fluorine atoms, bromine atoms, etc.), alkoxy groups (methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), alkyloxycarbonyl groups, alkyloxycarbonyl groups. Etc.

The alicyclic group as X may be monocyclic, polycyclic, or bridged, and preferably represents an alicyclic group having 5 to 25 carbon atoms.
In addition, the alicyclic group may have a substituent, and examples of the substituent include the same as those exemplified as the substituent of R ₂ above, and alkyl groups (methyl group, ethyl group, propyl group). Group, butyl group, etc.).
X preferably represents an alicyclic group having 5 to 25 carbon atoms, more preferably an alicyclic group having 6 to 20 carbon atoms, and particularly preferably a cycloalkyl group having 7 to 15 carbon atoms.
Below, the structural example of the alicyclic group as X is shown.

Preferred examples of the alicyclic group include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. , 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.
The alicyclic group as X is more preferably a bridged alicyclic group, and particularly preferably an adamantyl group.

  Hereinafter, although the specific example of the repeating unit represented by General formula (1) is given, this invention is not limited to this.

In the general formula (2), R ₄ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group having 1 to 4 carbon atoms (C _m F _{2m + 1} group, and m is 1 to 4 Represents an integer). R ₄ is preferably a hydrogen atom, a methyl group, or a C _m F _{2m + 1} group (m is preferably 1), and particularly preferably a hydrogen atom or a methyl group.

The alkyl group as R ₅ may have a substituent and is preferably an alkyl group having 1 to 8 carbon atoms. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- A butyl group, a hexyl group, an octyl group, etc. can be mentioned.
The alkoxy group as R ₅ may have a substituent and is preferably an 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.
The aryl group as R ₅ may have a substituent, and is preferably an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group, a tolyl group, a naphthyl group, and an anthryl group. it can.
The acyl group as R ₅ may have a substituent, and is preferably an acyl group having 2 to 8 carbon atoms. For example, formyl group, acetyl group, propanoyl group, butanoyl group, pivaloyl group, benzoyl Groups and the like.
The substituents that these groups may have include hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group) Etc.).

  In the general formula (2), the OH group may be in any position on the benzene ring, but is preferably the meta position or the para position of the styrene skeleton, and particularly preferably the para position.

  l represents an integer of 0 to 4, preferably 0 to 2, and particularly preferably 0 or 1.

  Although the specific example of the repeating unit represented by General formula (2) below is given, this invention is not limited to this.

In general formula (3), R ₆ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group (C _m F _{2m + 1} group having from 1 to 4 carbon atoms, m is 1 to 4 Represents an integer). R ₄ is preferably a hydrogen atom, a methyl group, or a C _m F _{2m + 1} group (m is preferably 1), and particularly preferably a hydrogen atom or a methyl group.

The alkyl group as R ₇ may have a substituent and is preferably an alkyl group having 1 to 8 carbon atoms. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- A butyl group, a hexyl group, an octyl group, etc. can be mentioned.
The alkoxy group as R ₇ may have a substituent and is preferably an 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.
The aryl group as R ₇ may have a substituent, preferably an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group, a tolyl group, a naphthyl group, and an anthryl group. it can.
The acyl group as R ₇ may have a substituent, and is preferably an acyl group having 2 to 8 carbon atoms. For example, formyl group, acetyl group, propanoyl group, butanoyl group, pivaloyl group, benzoyl Groups and the like.

The alkyl group as R ₈ may have a substituent and is preferably an alkyl group having 1 to 8 carbon atoms. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group, a tert-butyl group, a pentyl group, a hexyl group, and an octyl group, and more preferred are an ethyl group, a propyl group, a tert-butyl group, and a hexyl group.
The alicyclic group as R ₈ may have a substituent, and examples thereof include the same as the alicyclic group of X in the general formula (1).
The aryl group as R ₈ may have a substituent, and is preferably an aryl group having 6 to 15 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthranyl group. A phenyl group or a naphthyl group is preferable.
The heterocyclic group as R ₈ may have a substituent, for example, a pyrrole ring group (residue obtained by removing one hydrogen atom from the pyrrole ring, the same shall apply hereinafter), a furan ring group, a thiophene ring group, Imidazole ring group, oxazole ring group, thiazole ring group, pyridine ring group, pyrazine ring group, pyrimidine ring group, pyridazine ring group, indolizine ring group, indole ring group, benzofuran ring group, benzothiophene ring group, isobenzofuran ring group Quinolidine ring group, quinoline ring group, phthalazine ring group, naphthyridine ring group, quinoxaline ring group, quinoxazoline ring group, isoquinoline ring group, carbazole ring group, phenanthridine ring group, acridine ring group, phenanthroline ring group, thianthrene ring group Chromene ring group, xanthene ring group, phenoxathiin ring group, phenothiazine ring group, phenazine ring group, etc. And the like.

Examples of the substituent that the R ₇ and R ₈ groups may have include, for example, a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkoxy group (methoxy group, ethoxy group) , Propoxy group, butoxy group, etc.).

m represents an integer of 0 to 4, preferably 0 to 2, and particularly preferably 0 or 1.
n represents an integer of 1 to 5, preferably 1 to 2, and particularly preferably 1.

In the general formula (3), the —OCOR ₈ group may be in any position on the benzene ring, but is preferably the meta position or the para position of the styrene skeleton, particularly preferably the para position.

  It is considered that the repeating unit represented by the general formula (3) is partially hydrolyzed in an alkaline developer, and improves the resist performance such as line edge roughness.

  Although the specific example of the repeating unit represented by General formula (3) below is given, this invention is not limited to this.

The content of the repeating unit represented by the general formula (1) in the resin (A) is preferably 5 to 80 mol%, more preferably 5 to 70 mol%, particularly preferably 5 in all repeating units. ˜50 mol%. 5 mol% or more is preferable in order to reliably prevent film loss and resolution reduction in the unexposed area, and 80 mol% or less is preferable from the viewpoint of adhesion to the substrate and scum suppression.
As for the content rate of the repeating unit represented by General formula (2) in resin (A), 5-90 mol% is preferable in all the repeating units, More preferably, it is 20-90 mol%, Especially preferably, 30 ˜80 mol%. 5% or more is preferable from the viewpoint of poor adhesion to the substrate and suppression of scum, and 90 mol% or less is preferable from the viewpoint of surely preventing a reduction in film thickness and a decrease in resolution in the unexposed area.
As for the content rate of the repeating unit represented by General formula (3) in resin (A), 10-90 mol% is preferable in all the repeating units, More preferably, it is 10-50 mol%, Most preferably, it is 10 ˜30 mol%. 10% or more is preferable from the viewpoint of poor adhesion to the substrate and suppression of scum, and 90 mol% or less is preferable from the viewpoint of surely preventing a reduction in film thickness and a decrease in resolution in the unexposed area.

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.
Furthermore, in addition to the acid-decomposable group contained in the general formula (1), the resin (A) may have a repeating unit of a monomer having another acid-decomposable group. A group represented by C (═O) —X ₁ —R ₀ can be given.
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.

The weight average molecular weight (Mw) of the resin (A) is preferably in the range of 1,000 to 200,000, more preferably in the range of 1,500 to 100,000, and particularly preferably 2,000. It is in the range of ~ 50,000. It is preferably 1,000 or more from the viewpoint of preventing the unexposed portion from being reduced in film thickness, and is preferably 200,000 or less from the viewpoint of slowing the dissolution rate of the resin itself in the alkali and reducing the sensitivity. The dispersity (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.5.
Here, the weight average molecular weight is defined by a polystyrene conversion value of gel permeation chromatography.

Moreover, you may use resin (A) in combination of 2 or more types, respectively.
The total amount of the resin (A) added is generally 10 to 96% by mass, preferably 15 to 96% by mass, and particularly preferably 20 to 95% by mass with respect to the total solid content of the positive resist composition. %.

  Although the specific example of resin (A) is given to the following, this invention is not limited to this.

[2] Acid generator (B) that generates acid upon irradiation with actinic rays or radiation
The acid generator (B) that generates acid upon irradiation with actinic rays or radiation contained in the positive resist composition of the present invention is an acid generator upon irradiation with actinic rays or radiation such as KrF excimer laser light, electron beam, EUV, etc. Examples of such compounds are diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

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

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

  In the present invention, preferred acid generators (B) from the viewpoint of improving image performance such as resolution and pattern shape include sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, and disulfones.

Preferable acid generators (B) 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. Two of R ₂₀₁ to R ₂₀₃ are bonded to the ring structure may be formed.
X ⁻ represents an anion.

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

The two of the group formed by bonding of the R ₂₀₁ to R _203, an alkylene group (e.g., butylene, pentylene), and an example of an oxygen atom, a sulfur atom, an ester bond, an amide bond And may contain a carbonyl group.

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

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

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

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

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

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

Examples of the aryl group of the arylsulfonium compound include an aryl group composed of a hydrocarbon and a heteroaryl group having a hetero atom such as a nitrogen atom, a sulfur atom, or an oxygen atom. The aryl group composed of hydrocarbon is preferably a phenyl group or a naphthyl group,
More preferred is a phenyl group. Examples of the heteroaryl group include a pyrrole group, an indole group, a carbazole group, a furan group, and a thiophene group, and an indole group is preferable. 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.

The aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (for example, having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), an aryl group (for example, having 6 to 6 carbon atoms). 14), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, a phenylthio group or the like may be used as a substituent. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms. Group, 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.

In the general formula (ZI), an anion of X ⁻ is preferably an organic anion. An organic anion represents an anion having at least one carbon atom. Furthermore, the organic anion is preferably a non-nucleophilic 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.
Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  Examples of the non-nucleophilic sulfonate anion include an alkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion. Examples of the non-nucleophilic carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

The alkyl moiety in the alkyl sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, such as a methyl group, Ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl Group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.
The aryl group in the aryl sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.
Examples of the substituent of the alkyl group, cycloalkyl group and aryl group in the alkyl sulfonate anion and aryl 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 1 to 5 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (preferably May include 2 to 7 carbon atoms, an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

Examples of the alkyl moiety in the alkylcarboxylate anion include the same alkyl group and cycloalkyl group as in the alkylsulfonate anion. Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate anion. The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.
Examples of the alkyl group, cycloalkyl group, aryl group and aralkyl group substituent in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom, alkyl group as in the arylsulfonate anion, A cycloalkyl group, an alkoxy group, an alkylthio group, etc. can be mentioned.

  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 the substituent for these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group.

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

The anion represented by X- is preferably a sulfonate anion, more preferably an aryl sulfonic acid.
Specific examples of the anion represented by X- include methanesulfonic acid anion, trifluoromethanesulfonic acid anion, pentafluoroethanesulfonic acid anion, heptafluoropropanesulfonic acid anion, perfluorobutanesulfonic acid anion, perfluorohexane. Sulfonate anion, perfluorooctane sulfonate anion, pentafluorobenzene sulfonate anion, 3,5-bistrifluoromethylbenzene sulfonate anion, 2,4,6-triisopropylbenzene sulfonate anion, perfluoroethoxyethane sulfonate anion 2,3,5,6-tetrafluoro-4-dodecyloxybenzenesulfonate anion, methanesulfonate anion, p-toluenesulfonate anion, 2,4,6-trimethylbenzenesulfonate anion, etc. And the like.

  When compound (ZI-1) has two or more cation moieties, compound (ZI-1) may have two or more monovalent anions or one divalent or more anion. You may have.

Next, the compound (ZI-2) will be described.
The compound (ZI-2) is, R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently is a compound when it represents an organic group having no aromatic ring.

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, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, most preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R _{201 to} R ₂₀₃ may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group. Butyl group, pentyl group and the like. More preferable examples of the alkyl group include a linear or branched 2-oxoalkyl group and an alkoxycarbonylmethyl group.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group. More preferable examples of the cycloalkyl group include a cyclic 2-oxoalkyl group.

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

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

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

  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 represent a hydrogen atom, an alkyl group, or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included.
Zc ⁻ represents an anion, and examples thereof include the same as the anion of X ^{− in} the general formula (ZI).

The alkyl group as R _{1c to} R _7c is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, A linear or branched pentyl group can be exemplified.

The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group and a cyclohexyl group.

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

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

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

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

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

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

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

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Examples of the aryl group of R _{204 to} R ₂₀₇ include an aryl group composed of a hydrocarbon and a heteroaryl group having a hetero atom such as a nitrogen atom, a sulfur atom, or an oxygen atom. The aryl group composed of hydrocarbon is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Examples of the heteroaryl group include a pyrrole group, an indole group, a carbazole group, a furan group, and a thiophene group, and an indole group is preferable.
The alkyl group as R ₂₀₄ to R ₂₀₇ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably a cycloalkyl group having 3 to 10 carbon atoms, e.g., cyclopentyl, cyclohexyl group and a norbornyl group.
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents an anion, and examples thereof include the same as the anion X ^{− in} the general formula (ZI).

  Preferred examples of the acid generator (B) further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₆ , R ₂₀₇ and R _{208 each} represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  Preferred examples of the acid generator (B) further include a compound represented by the following general formula (ZVII).

In general formula (ZVII),
R _210a and R _211a each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a cyano group, a nitro group or an alkoxycarbonyl group, preferably a halogen-substituted alkyl group or a cycloalkyl group, a nitro group or a cyano group. is there.
R _212a represents a hydrogen atom, an alkyl group, a cycloalkyl group, a cyano group or an alkoxycarbonyl group.
X _1a represents a monovalent group formed by removing a hydrogen atom of —SO ₃ H of an organic sulfonic acid.

  Preferred examples of the acid generator (B) further include compounds represented by the following general formula (ZVIII).

In general formula (ZVIII):
Ra represents an alkyl group, a cycloalkyl group, or an aryl group. When there are a plurality of Ras, the plurality of Ras may be the same or different.
n represents an integer of 1 to 6.

  Hereinafter, although the specific example of an acid generator (B) is given, this invention is not limited to this.

  As for an acid generator (B), the compound represented by general formula (ZI) is more preferable, and a compound (ZI-1) is especially preferable.

The content of the acid generator (B) is preferably 5 to 20% by mass, more preferably 6 to 18% by mass, particularly preferably 7 to 16%, based on the solid content of the positive resist composition. % By mass. It is 5% by mass or more from the viewpoint of sensitivity and line edge roughness, and 20% by mass or less from the viewpoint of resolution, pattern shape, and film quality.
One type of acid generator (B) may be used, or two or more types may be mixed and used.

[3] Organic Basic Compound In the present invention, it is preferable to use an organic basic compound from the viewpoint of improving performance such as resolution and improving storage stability. As the organic basic compound, a compound containing a nitrogen atom is more preferable.
A preferable organic basic compound in the present invention is a compound having a stronger basicity than phenol.
As a preferable chemical environment, structures of the following formulas (A) to (E) can be exemplified. Formulas (B) to (E) may be part of a ring structure.

In the formula (A), R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group, or an aryl group having 6 to 20 carbon atoms. Here, R ²⁰¹ and R ²⁰² may combine with each other to form a ring.
The alkyl group, cycloalkyl group and aryl group as R ²⁰⁰ , R ²⁰¹ and R ²⁰² may have a substituent. As the alkyl group and cycloalkyl group having a substituent, an aminoalkyl group having 1 to 20 carbon atoms and an aminocycloalkyl group, and a hydroxyalkyl group having 1 to 20 carbon atoms are preferable.
In the formula (E), R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 6 carbon atoms and a cycloalkyl group.
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

  Preferred examples include guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, imidazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine and the like. Preferred substituents that these may have include amino groups, alkylamino groups, aminoaryl groups, arylamino groups, alkyl groups (substituent alkyl groups, particularly aminoalkyl groups), alkoxy groups, acyl groups, and acyloxy groups. , 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, piperazine, N- (2-aminoethyl) piperazine N- (2-aminoethyl) piperi 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, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, Examples thereof include, but are not limited to, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine.
These nitrogen-containing basic compounds are used alone or in combination of two or more.

  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 (total amount of acid generator) / (organic basic compound) (molar ratio) = 2.5 to 300. By setting the molar ratio to 2.5 or more, high sensitivity is obtained, and by setting the molar ratio to 300 or less, it is possible to suppress the resist pattern from becoming thicker over time until post-exposure heat treatment and improve resolution. . (Total amount of acid generator) / (organic basic compound) (molar ratio) is preferably 5.0 to 200, more preferably 7.0 to 150.

[4] 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 Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as bitane monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, Ftop EF301, EF303, EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), Megafac F171, F173 (manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431 (manufactured by 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.), etc. Hexane polymer KP341 (manufactured by Shin-Etsu Chemical Co.) 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. 3,606,921, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the positive resist composition (excluding the solvent).

[5] 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. 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.

  The 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.

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

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

[Synthesis Example 1: Synthesis of Resin (A-1)]
p-Acetoxystyrene and 1- (1-adamantyl) -1-methylethyl methacrylate were charged at a ratio (molar ratio) of 80/20 and dissolved in cyclohexanone to prepare 750 mL of a solution having a solid content concentration of 20% by mass. 20 mol% of dimethyl 2,2-azobis (2-methylpropionate) was added to this solution, and this was added dropwise to 150 mL of dichlorohexanone heated to 80 ° C. over 6 hours under a nitrogen atmosphere. After completion of dropping, the reaction solution was stirred for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 3 L of hexane, and the precipitated white powder was collected by filtration to obtain 155 g. The obtained crystals are dissolved in a mixed solution of 600 ml of tetrahydrofuran and 300 ml of methanol, and a 20 mass% tetramethylammonium hydroxide aqueous solution is added dropwise over 15 minutes. After stirring at room temperature for 4 hours, 500 ml of ethyl acetate and 150 ml of 5% by mass hydrochloric acid are added for liquid separation. The organic layer is separated and washed 4 times with 300 ml of water. The organic layer is distilled off under reduced pressure, then dissolved in 400 ml of ethyl acetate and crystallized in 2.5 L of hexane. The precipitated white powder is collected by filtration to obtain 102 g of crystals. The obtained crystals are dissolved in 500 ml of PGMEA, and 6.5 g of pyridine and 7.0 g of acetic anhydride are added. After reacting at room temperature for 2 hours, 400 ml of ethyl acetate is added to separate the layers. The organic layer is washed twice with 400 ml of water, and then the organic layer is distilled off under reduced pressure. Thereafter, the resultant was dissolved in 300 ml of ethyl acetate, crystallized and precipitated in 2 L of hexane, collected by filtration, and dried to obtain a resin (A-1).
The composition ratio of the resin (A-1) determined from H1NMR was hydroxystyrene / 1- (1-adamantyl) -1-methylethyl methacrylate / acetoxystyrene = 70/20/10. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 7800, and dispersion degree (Mw / Mn) was 1.87.
Resins (A-2), (A-4), (A-7), (A-13), (A-16) whose structures have been exemplified above, as shown in Table 1 in the same manner as in Synthesis Example 1 , (A-18) was synthesized. In Table 1, repeating units 1, 2, and 3 correspond to the repeating units in order from the left.

[Example 1]
(1) Preparation and coating of positive resist Resin (A-1) 0.93 g
0.07 g of acid generator (B-2)
Is dissolved in 8.8 g of propylene glycol monomethyl ether acetate, and further, 0.003 g of (D-1) (see below) as an organic basic compound and Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc.) as a surfactant. , hereinafter referred to as "W-1") added 0.001 g, was dissolved, the resulting solution was microfiltered through a membrane filter of 0.1μm pore size to obtain a resist solution.
This resist solution was applied onto a 6-inch silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and baked at 110 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.25 μm.

(2) Creation of positive resist pattern This resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750, acceleration voltage 50 KeV manufactured by Hitachi, Ltd.). 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.

(2-1) Sensitivity The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). Sensitivity was defined as the minimum irradiation energy when resolving a 0.15 μm line (line: space = 1: 1).
(2-2) Resolving power The resolving power was defined as the limiting resolving power (the line and space were separated and resolved) at the irradiation dose showing the above sensitivity.
(2-3) Line Edge Roughness The line width was measured at any 30 points in the length direction 50 μm of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, the standard deviation was obtained, and the variation was evaluated with 3σ. .
The results of Example 1 are shown in Table 2.

[Examples 2 to 9]
Using the components shown in Table 2, resist preparation / coating and electron beam exposure evaluation were performed in the same manner as in Example 1.

[Comparative Example 1]
Resist preparation / coating and electron beam exposure evaluation were performed in the same manner as in Example 1 except that the resin (AA-1) shown below was used.

  The evaluation results of Examples 2 to 9 and Comparative Example 1 are shown in Table 2 together with the evaluation results of Example 1.

The symbols for each component in Table 2 are as follows.
The resin and acid generator (B) are those listed above. The organic basic compound, surfactant and solvent are as follows.

[Organic basic compounds]
D-1: tri-n-hexylamine D-2: 2,4,5-triphenylimidazole D-3: tetra- (n-butyl) ammonium hydroxide D-4: triphenylsulfonium acetate D-5: N -Hydroxyethylpiperidine D-6: 2,6-diisopropylaniline D-7: Tripentylamine

[Surfactant]
W-1: Fluorosurfactant, Megafac F-176 (Dainippon Ink Chemical Co., Ltd.)
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.)

〔solvent〕
C1: propylene glycol methyl ether acetate C2: 2-heptanone C3: cyclohexanone C4: γ-butyrolactone C5: propylene glycol methyl ether C6: ethyl lactate

  From Table 2, it can be seen that the positive resist composition of the present invention is higher in sensitivity and resolution and superior in line edge roughness as compared with the compound of the comparative example with respect to pattern formation by electron beam irradiation.

Example 10
Resist preparation and coating were performed using the components shown in Table 3 in exactly the same manner as in Example 1 to obtain a resist film. However, the film thickness was 0.40 μm.

(3) Formation of positive pattern The obtained resist film was subjected to pattern exposure using a KrF excimer laser stepper (FPA3000EX-5 manufactured by Canon Inc., wavelength 248 nm). The post-exposure processing was performed in the same manner as in Example 1. The pattern was evaluated as follows.

(3-1) Sensitivity The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). Sensitivity was defined as the minimum irradiation energy when resolving a 0.18 μm line (line: space = 1: 1).
(3-2) Resolving power The resolving power was defined as the limiting resolving power (line and space are separated and resolving) at the irradiation amount showing the above sensitivity.
(3-3) Line Edge Roughness The line width is measured at any 30 points in the length direction of 50 μm of the 0.18 μm line pattern at the irradiation dose showing the above sensitivity, the standard deviation is calculated, and the variation is evaluated by 3σ. did.
The results of Example 10 are shown together in Table 3.

[Examples 11 to 18]
Using the components shown in Table 3, resist preparation / coating and KrF excimer laser exposure evaluation were performed in exactly the same manner as in Example 10.

[Comparative Example 2]
A resist was prepared and coated in the same manner as in Example 10 except that the resin AA-1 was used, and KrF excimer laser exposure evaluation was performed.

  The evaluation results of Examples 11 to 18 and Comparative Example 2 are shown in Table 3 together with the evaluation results of Example 10.

  From Table 3, it can be seen that the positive resist composition of the present invention has higher sensitivity, higher resolution, and better line edge roughness than the comparative example with respect to pattern formation by KrF excimer laser exposure.

[Examples 19 to 27]
Using each resist composition of Examples 1 to 9, a resist film was obtained in the same manner as in Example 1. However, the resist film thickness was 0.13 μm. The obtained resist film was subjected to surface exposure using EUV light (wavelength 13 nm) while changing the exposure amount by 0.5 mJ in the range of 0 to 5.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure dose was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast.

[Comparative Example 3]
A resist was prepared and coated in the same manner as in Example 19 except that AA-1 was used as the resin, and exposure evaluation with EUV light was performed.

  The evaluation results of Examples 19 to 27 and Comparative Example 3 are shown in Table 4.

  From Table 4, it can be seen that the positive resist composition of the present invention is superior in sensitivity and high contrast as compared with the composition of the comparative example in the property evaluation by irradiation with EUV light.

Claims (7)

Insoluble repeating units of which are represented by the following general formula (1), the repeating units of which are represented by the following general formula (2), and, consisting of a repeating unit represented by the following general formula (3), in an alkaline developer Alternatively, a positive resist composition comprising a resin (A) which is hardly soluble and has a property of being soluble in an alkali developer by the action of an acid.

In general formula (1),
R ₁ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₂ and R ₃ each independently represents an alkyl group.
X represents an alicyclic group.
In general formula (2),
R ₄ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom, or a perfluoroalkyl group having 1 to 4 carbon atoms.
R ₅ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
l represents an integer of 0 to 4.
In general formula (3),
R ₆ represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a C 1-4 perfluoroalkyl group.
R ₇ represents an alkyl group, a halogen atom, an aryl group, an alkoxy group or an acyl group.
R ₈ represents an alkyl group, an alicyclic group, an aryl group, or a heterocyclic group.
m represents an integer of 0 to 4.
n represents an integer of 1 to 5.   The resin (A) is represented by 5 to 80 mol% of the repeating unit represented by the general formula (1), 5 to 90 mol% of the repeating unit represented by the general formula (2), and represented by the general formula (3). The positive resist composition according to claim 1, comprising 10 to 90 mol% of repeating units.   Furthermore, it contains an acid generator (B) that generates an acid upon irradiation with actinic rays or radiation, and the content of the acid generator (B) is 5 to 20 mass based on the total solid content of the positive resist composition. The positive resist composition according to claim 1, wherein the positive resist composition is%.   The positive resist composition according to claim 1, wherein X in the general formula (1) is a bridged alicyclic group.   The positive resist composition according to claim 4, wherein X in the general formula (1) is an adamantyl group.   A resist film formed from the positive resist composition according to claim 1. Patterning method against Les resist film according to claim 6, exposure, and performing development.