JP4324496B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition used in an ultramicrolithography process such as the manufacture of a VLSI and a high-capacity microchip and other photofabrication processes, and a pattern forming method using the same.

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

  In general, chemically amplified resists can be broadly classified into three types, commonly called two-component systems, 2.5-component systems, and three-component systems. The two-component system combines a compound that generates an acid by photolysis (hereinafter referred to as a photoacid generator) and a binder resin. The binder resin is a resin having in its molecule a group (also referred to as an acid-decomposable group) that decomposes by the action of an acid and increases the solubility of the resin in an alkaline developer. The 2.5 component system further contains a low molecular weight compound having an acid-decomposable group in the two component system. A three-component system contains a photoacid generator, an alkali-soluble resin, and the low molecular weight compound.

  The chemically amplified resist is suitable as a photoresist for ultraviolet or far ultraviolet irradiation, but in the recent ArF resist process, it is desired to form a line pattern and a hole pattern of 120 nm or less smaller than the exposure wavelength. With this miniaturization, the PEB temperature-dependent performance in the device manufacturing process has become a problem. In the image formation by the chemically amplified resist, the acid generated by exposure is thermally diffused by heating after exposure (PEB: Post Exposure Bake) to decompose the acid-decomposable group in the binder resin, and in an alkaline developer of the resin. It uses a reaction mechanism that increases the solubility of. For this reason, resist characteristics (PEB temperature dependency) are required in which the change in size of the finished pattern is small with respect to in-plane and inter-apparatus temperature variations of the hot plate used for PEB in the device manufacturing process.

Patent Document 1 (Japanese Patent Laid-Open No. 2003-84438) discloses a repeating unit having adamantane and a repeating unit having norbornane as a resin for a resist material having a resolution, etching resistance, and heat treatment temperature. It proposes a resin to contain.
However, further reduction of PEB temperature dependency is desired.

  Accordingly, an object of the present invention is a positive resist which can be suitably used in an ultramicrolithography process such as VLSI manufacturing or high-capacity microchip manufacturing and other photofabrication processes, and has improved PEB temperature dependency. It is providing the composition and the pattern formation method using the same.

JP 2003-84438 A

  The above object is achieved by a positive resist composition having the following constitution and a pattern forming method using the same.

(1) A positive resist composition comprising two kinds of resins containing a group that decomposes by the action of an acid and increases the solubility in an alkaline developer, and a compound that generates an acid upon irradiation with actinic rays or radiation. ,
Each of the two types of resins contains at least one of a repeating unit derived from an acrylic acid derivative monomer and a repeating unit derived from a methacrylic acid derivative monomer, and an alicyclic structure, and has a weight average molecular weight of 4500 to 4500 . A positive resist composition having a range of 9370, wherein the difference between the weight average molecular weights of the two kinds of resins is 2000 or more.

  (2) At least one of the two kinds of resins contains at least one of the repeating unit represented by the general formula (A1) and the repeating unit represented by the general formula (A2). The positive resist composition as described in (1) above.

R represents a hydrogen atom, a hydroxyl group, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group or a urea group, or a combination of two or more groups. To express.
W ₁ represents an alkylene group.

  (3) The positive resist composition as described in (1) or (2) above, wherein at least one of the two kinds of resins contains a repeating unit represented by the following general formula (A3): object.

R ₃ and ₄ each independently represent a hydrogen atom or a methyl group.

  (4) A pattern forming method comprising: forming a resist film from the positive resist composition according to any one of (1) to (3) above; and exposing and developing the resist film.

  According to the present invention, it is possible to provide a positive resist composition excellent in PEB temperature dependency with a small change in the size of the finished pattern with respect to in-plane and inter-apparatus temperature variations of the hot plate used for PEB in the device manufacturing process.

Hereinafter, the compounds used in the present invention will be described in detail.
In addition, in the description of group (atomic group) in this specification, the description which is not describing substitution and non-substitution includes what has a substituent with what does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
Although this invention is invention which concerns on said (1)-(4), hereafter, other matters are also described.

[1] Resin (component A)
The resist composition of the present invention contains two types of resins (acid-decomposable resins) containing groups (acid-decomposable groups) that are decomposed by the action of an acid and increase the solubility in an alkaline developer.
These two acid-decomposable resins have an alicyclic structure and contain at least one of a repeating unit derived from an acrylic acid derivative monomer and a repeating unit derived from a methacrylic acid derivative monomer. The two kinds of acid-decomposable resins have a weight average molecular weight of 4500 or more, and the difference is 2000 or more.
Here, “acrylic acid derivative monomer” and “methacrylic acid derivative monomer” are used to include acrylic acid monomer and methacrylic acid monomer, respectively.

  Examples of the alicyclic structure contained in the resin include repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI).

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group 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 (pVI), the alkyl group in R _{12 to} R ₂₅ may be substituted or unsubstituted, and is a linear or branched alkyl group having 1 to 4 carbon atoms. Represents. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

The alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

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

  Examples of the substituent that these alicyclic hydrocarbon groups 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 alkoxy group as a substituent may further have a substituent such as a hydroxyl group, a halogen atom, or an alkoxy group.

The structures represented by the general formulas (pI) to (pVI) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.
Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.
Preferred examples of the alkali-soluble group (acid-decomposable group) protected by the structure represented by the general formulas (pI) to (pVI) include groups represented by the following general formulas (pVII) to (pXI).
That is, groups represented by the following general formulas (pVII) to (pXI) have an alicyclic structure and are also acid-decomposable groups.

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

In the resin used in the present invention, a repeating unit having an alkali-soluble group protected by a group having an alicyclic structure represented by general formulas (pI) to (pVI), that is, an alicyclic structure and an acid-decomposable group. It is preferable to contain the repeating unit which has.
An example of such a repeating unit is a repeating unit represented by the following general formula (pA).

Here, each R independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
A is a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups Represents.
Ra represents any group of the above formulas (pI) to (pVI).

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

  The resin according to the present invention may have an acid-decomposable group in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI), You may have in the at least 1 sort (s) of repeating unit among the repeating units of a postscript copolymerization component.

As the acid-decomposable group, in addition to the alkali-soluble group (acid-decomposable group) protected by the structure represented by the general formulas (pI) to (pVI) described above, for example, —C (═O) —X ₁ it can be exemplified those represented by -R _0.
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- 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 an -NHSO ₂ NH-.

  In the present invention, it is particularly preferable that at least one of the two kinds of resins contains at least one of the repeating units represented by the following general formulas (A1) and (A2).

R represents a hydrogen atom, a hydroxyl group, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms, such as a methyl group or an ethyl group). A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group or a urea group, or a combination of two or more groups. To express.
W ₁ represents an alkylene group.

Examples of the alkylene group for A and W ₁ include groups represented by the following formulas.
− [C (Rf) (Rg)] r ₁ −
In the formula, Rf and Rg represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and both may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of 1 to 10.

  Specific examples of the repeating units represented by the general formulas (A1) and (A2) are listed below as corresponding monomers, but are not limited thereto.

  It is preferable that at least one of the two kinds of resins contained in the positive resist composition of the present invention contains a repeating unit represented by the general formula (A3).

R ₃ and ₄ each independently represent a hydrogen atom or a methyl group.

  Moreover, it is preferable that resin contains the repeating unit which has group represented by the following general formula (I).

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

  The group represented by formula (I) is preferably a dihydroxy form or a monohydroxy form, and particularly preferably a dihydroxy form.

  Examples of the repeating unit having a group represented by the general formula (I) include a repeating unit represented by the following general formula (AII).

In general formula (AII), R _1c represents a hydrogen atom.
R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

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

  The resin can further contain a repeating unit having a lactone structure represented by the following general formula (IV).

In the general formula (IV), R ₁ a represents a hydrogen atom or a methyl group.
W ₁ represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, or a group of two or more groups selected from the group consisting of an ester group.
Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. m and n each independently represent an integer of 0 to 3, and m + n is 2 or more and 6 or less.

Examples of the alkyl group having 1 to 4 carbon atoms of Ra _{1 to} Re ₁ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Can do.

Examples of the substituent that the alkyl group may have include a carboxyl group, an acyloxy group, a cyano group, a cycloalkyl group, a halogen atom, a hydroxyl group, an alkoxy group, an acetylamide group, an alkoxycarbonyl group, and an acyl group. Here, examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, and a cyclopentyl 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.
Examples of the acyloxy group include an acetoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkylene group for W ₁ include groups represented by the following formulae.
− [C (Rf) (Rg)] r ₁ −
In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group or an alkoxy group, and both may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of 1 to 10.

  Hereinafter, although the specific example of the monomer corresponding to the repeating unit shown by general formula (IV) is shown, it is not limited to these.

In the specific example of the general formula (IV), (IV-17) to (IV-36) are preferable because the exposure margin becomes better.
Further, as the structure of the general formula (IV), those having an acrylate structure are preferable from the viewpoint that the edge roughness becomes good.

  Moreover, although you may contain the repeating unit which has group represented by either of the following general formula (V-1)-(V-4), it has group represented by general formula (V-1). Repeat units are particularly preferred.

In General Formulas (V-1) to (V-4), R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. Two of R _{1b to} R _5b may combine to form a ring.

In the general formulas (V-1) to (V-4), examples of the alkyl group in R _{1b to} R _5b include linear and branched alkyl groups, which may have a substituent.
The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. More preferably, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl It is a group.
As a cycloalkyl group in R _<1b > -R < _5b >, C3-C8 things, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, are preferable.
As an alkenyl group in R _<1b > -R < _5b >, C2-C6 things, such as a vinyl group, a propenyl group, a butenyl group, a hexenyl group, are preferable.
Examples of the ring formed by combining two of R _{1b to} R _5b include 3- to 8-membered rings such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring.
In the general formulas (V-1) to (V-4), R _{1b to} R _5b may be connected to any carbon atom constituting the cyclic skeleton.

  Moreover, as a preferable substituent which the said alkyl group, a cycloalkyl group, and an alkenyl group may have, a C1-C4 alkoxy group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), Examples thereof include an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, and a nitro group.

  Examples of the repeating unit having a group represented by general formulas (V-1) to (V-4) include a repeating unit represented by the following general formula (V).

In General Formula (V), R _0b represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. As a preferable substituent which the alkyl group of R _0b may have, the alkyl group as R _{1b to} R _5b in the general formulas (V-1) to (V-4) may preferably have. What was illustrated previously as a substituent is mentioned.
Examples of the halogen atom for R _0b include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R _0b is preferably a hydrogen atom.
A _b represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.
V represents a group represented by any one of the general formulas (V-1) to (V-4). In A _b, examples of the divalent group in combination the include for example those of the following formulas.

In the above formula, R _ab and R _bb represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and both may be the same or different.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent that the alkyl group may have include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r1 represents an integer of 1 to 10, preferably an integer of 1 to 4. m represents an integer of 1 to 3, preferably 1 or 2.

  Although the specific example of the repeating unit represented by general formula (V) is given to the following, the content of this invention is not limited to these.

  The resin can further contain a repeating unit represented by the following general formula (VI).

In the general formula (VI), A ₆ represents a single bond, an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group, or a group of two or more groups selected from the group consisting of ester groups.
R _6a represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen atom.

In the general formula (VI), examples of the alkylene group represented by A ₆ include groups represented by the following formulae.
-[C (Rnf) (Rng)] r-
In the above formula, Rnf and Rng represent a hydrogen atom, an alkyl group, a halogen atom, a hydroxyl group, and an alkoxy group, and both may be the same or different.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Here, the alkyl group and the alkoxy group may further have a substituent such as a hydroxyl group, a halogen atom, or an alkoxy group.
r is an integer of 1-10.
In the general formula (VI), examples of the cycloalkylene group represented by A ₆ include those having 3 to 10 carbon atoms, and examples thereof include a cyclopentylene group, a cyclohexylene group, and a cyclooctylene group.

The bridged alicyclic ring containing Z ₆ may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), an alkoxycarbonyl group (preferably having 1 to 5 carbon atoms), an acyl group (for example, a formyl group and a benzoyl group), an acyloxy group ( For example, propyl carbonyloxy group, benzoyloxy group), an alkyl group (preferably having from 1 to 4 carbon atoms), a carboxyl group, a hydroxyl group and an alkylsulfonylsulfamoyl group (-CONHSO ₂ CH _3, etc.). In addition, the alkyl group as a substituent may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), or the like.

In the general formula (VI), the oxygen atom of the ester group bonded to A ₆ may be bonded at any position of the carbon atom constituting the bridged alicyclic ring structure containing Z ₆ .

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

  In addition to the above repeating units, the resin is various for the purpose of adjusting dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required characteristics of resist, such as resolution, heat resistance, and sensitivity. Repeating units.

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

Specifically, the following monomers can be mentioned.
Acrylic acid esters (preferably alkyl acrylates having an alkyl group with 1 to 10 carbon atoms):
Methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxy Propyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, and the like.

Methacrylic acid esters (preferably alkyl methacrylate having 1 to 10 carbon atoms in the alkyl group):
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2 , 2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate and the like.

Acrylamides:
Acrylamide, N-alkylacrylamide (alkyl group having 1 to 10 carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, t-butyl group, heptyl group, octyl group, cyclohexyl group, hydroxyethyl group, etc. N, N-dialkylacrylamide (alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, butyl, isobutyl, ethylhexyl, cyclohexyl, etc.), N-hydroxy Ethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like.

Methacrylamide:
Methacrylamide, N-alkylmethacrylamide (alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cyclohexyl, etc.), N, N -Dialkylmethacrylamide (there are alkyl groups such as ethyl group, propyl group, butyl group), N-hydroxyethyl-N-methylmethacrylamide and the like.

Allyl compounds:
Allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol and the like.

Vinyl ethers:
Alkyl vinyl ethers (eg hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, Diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and the like.

Vinyl esters:
Vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl acetoacetate, vinyl lactate, vinyl -Β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

Dialkyl itaconates:
Dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.
Dialkyl esters or monoalkyl esters of fumaric acid; dibutyl fumarate and the like.

  Others include crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilonitrile and the like.

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

  In the resin, the molar ratio of each repeating unit adjusts resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general resist performance such as resolution, heat resistance, and sensitivity. Therefore, it is set appropriately.

The content of the repeating unit having an alicyclic structure is preferably 30 to 100 mol%, more preferably 35 to 100 mol%, and still more preferably 40 to 100 mol% in all repeating units constituting the resin.
The content of the repeating unit having an acid-decomposable group is preferably from 15 to 70 mol%, more preferably from 20 to 65 mol%, still more preferably from 25 to 60 mol%, based on all repeating units constituting the resin.
The content of the repeating unit derived from the acrylic acid derivative monomer is preferably from 5 to 70 mol%, more preferably from 10 to 60 mol%, still more preferably from 15 to 50 mol% in all repeating units constituting the resin. .
The content of the repeating unit derived from the methacrylic acid derivative monomer is preferably 30 to 95 mol%, more preferably 40 to 90 mol%, still more preferably 50 to 85 mol% in all the repeating units constituting the resin. is there.
The total content of the repeating units represented by the general formulas (A1) and (A2) is preferably 5 to 95 mol%, more preferably 10 to 85 mol%, still more preferably 15 to 75 in all repeating units. Mol%.
As for content of the repeating unit represented by general formula (A3), 10-80 mol% is preferable in all the repeating units, More preferably, it is 15-75 mol%, More preferably, it is 20-70 mol%.
The content of the repeating unit having a group represented by the formula (I) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, still more preferably 15 to 35 mol% in all repeating units. .

Further, the content of the repeating unit based on the monomer of the further copolymer component in the resin can be appropriately set according to the performance of the desired resist.
When the composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

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

  The repeating structural units represented by the above specific examples may be used singly or in combination.

The weight average molecular weight of the resin according to the present invention is preferably 4,500 to 200,000, more preferably 5,000 to 20,000, in terms of polystyrene by gas permeation chromatography (GPC) method. is there. The weight average molecular weight is preferably 4,500 or more from the viewpoint of heat resistance and dry etching resistance, and 200,000 or less is preferable from the viewpoint of developability, viscosity, and film-forming property.
The dispersity (Mw / Mn) is usually 1 to 10, preferably 1 to 5, and more preferably 1 to 4. The smaller the degree of dispersion, the smoother the resolution, resist shape, and resist pattern side walls, and the better the roughness.

The two resins contained in the resist composition of the present invention are resins having an average weight molecular weight difference of 2000 or more, more preferably 2500 or more, and particularly preferably 3000 or more.
In addition, as an upper limit of the average weight molecular weight difference, 20000 or less is preferable, 17000 or less is more preferable, and 14000 or less is still more preferable.

The resin having a high average weight molecular weight is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, based on the total amount of the two resins contained in the resist composition of the present invention. It is especially preferable that it is -70 mass%.
The total amount of the two resins is preferably 50 to 100% by mass and more preferably 70 to 100% by mass with respect to the total resin contained in the resist composition of the present invention.

  In the positive resist composition of the present invention, the total amount of the resin is preferably 40 to 99% by mass, more preferably 50 to 98% by mass in the total resist solid content.

[2] Compound that generates acid upon irradiation with actinic rays or radiation (component B)
The composition of this invention contains the compound (photo-acid generator) which generate | occur | produces an acid by irradiation of actinic light or a radiation.
Such photoacid generators include ArF excimers used in photocationic photoinitiators, photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, and microresists. A known compound that generates an acid upon irradiation with an actinic ray or radiation such as a laser (193 nm), F ₂ excimer laser (157 nm), radiation, electron beam, X-ray, ion beam, or a mixture thereof is appropriately selected and used. can do.

  For example, diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts, organic halogen compounds, organic metal / organic halides, photoacid generators having o-nitrobenzyl type protecting groups Examples thereof include disulfone compounds and compounds that generate photosulfonic acid by photolysis, such as agents and iminosulfonates.

  Further, a group which 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, JP 63- The compounds described in No. 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.

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, the compounds represented by formula (PAG1) or (PAG2) that are particularly effectively used will be described below.

  (1) A compound represented by the following general formula (PAG1) or a compound represented by the general formula (PAG2).

In the formula (PAG1), Ar ¹ and Ar ² each independently represents an aryl group. The aryl group as Ar ¹ and Ar ² may have a substituent, and preferred substituents include alkyl groups (particularly haloalkyl groups as substituted alkyl groups), cycloalkyl groups, aryl groups, alkoxy groups, nitro groups. Group, carboxyl group, alkoxycarbonyl group, hydroxy group, mercapto group and halogen atom.

In the formula (PAG2), R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represents an alkyl group or an aryl group.
The alkyl group or aryl group as R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ may have a substituent, preferably an aryl group having 6 to 14 carbon atoms or an alkyl group having 1 to 8 carbon atoms.

Preferred substituents include an alkoxy group (preferably 1 to 8 carbon atoms), an alkyl group (preferably 1 to 8 carbon atoms), a nitro group, a carboxyl group, a hydroxy group, and a halogen atom for the aryl group. An alkyl group having 1 to 8 carbon atoms (preferably 1 to 8 carbon atoms), a carboxyl group, an alkoxycarbonyl group (preferably having 2 to 2 carbon atoms).
9).

Z ^- represents a counter anion, Z in the general formula (PAG6) to be described later ^- is the same as.

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ , Ar ¹ and Ar ² may be bonded via a single bond or a substituent.

  Specific examples include the following compounds, but are not limited thereto.

  The above onium salts represented by the general formulas (PAG1) and (PAG2) are known, and can be synthesized, for example, by the methods described in US Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331.

  (2) A disulfone derivative represented by the following general formula (PAG3) or an iminosulfonate derivative represented by the general formula (PAG4).

In the formula (PAG3), Ar ³ and Ar ⁴ each independently represent an aryl group.
^{R206 represents} an alkyl group, a cycloalkyl group or an aryl group. A represents an alkylene group, an alkenylene group or an arylene group.
Preferred substituents that these groups may have include, as preferred substituents, an aryl group with an alkoxy group (preferably having 1 to 8 carbon atoms) and an alkyl group (preferably having 1 to 8 carbon atoms). , A nitro group, a carboxyl group, a hydroxy group, and a halogen atom, and an alkyl group and a cycloalkyl group having 1 to 8 carbon atoms (preferably 1 to 8 carbon atoms), a carboxyl group, and an alkoxycarbonyl group. (Preferably having 2 to 9 carbon atoms).
Specific examples include the following compounds, but are not limited thereto.

(3) A diazodisulfone derivative represented by the following general formula (PAG5).

Each R independently represents an alkyl group, a cycloalkyl group or an aryl group.
Preferred substituents that these groups may have include alkoxy groups (preferably having 1 to 8 carbon atoms), alkyl groups (preferably having 1 to 8 carbon atoms), nitro groups, and carboxyl groups for aryl groups. A hydroxy group and a halogen atom, and an alkyl group and a cycloalkyl group having 1 to 8 carbon atoms (preferably 1 to 8 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (preferably having 2 carbon atoms). ~ 9).

Specific examples include the following compounds, but are not limited thereto.

(4) A compound represented by the following general formula (PAG6).

R represents an alkyl group, a cycloalkyl group or an aromatic group.
Y ₃ represents a single bond or a divalent linking group.
R ₆ and R ₇ represent a hydrogen atom, a cyano group, an alkyl group or an aryl group. R ₆ and R ₇ may combine to form a ring.
Y ₁ and Y ₂ represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an aromatic group containing a hetero atom, and Y ₁ and Y ₂ may be bonded to form a ring.
Z ⁻ represents a counter anion.

The alkyl group, cycloalkyl group or aromatic group as R preferably has 20 or less carbon atoms.
The aromatic group as R is preferably a group represented by the following formula (Va) or a naphthyl group.

In the formula (PAG6),
R _{1 to} R ₅ represent a hydrogen atom, an alkyl group, an alkoxy group, a nitro group, a halogen atom, an alkyloxycarbonyl group or an aryl group, and at least two of R _{1 to} R ₅ are bonded to form a ring structure. It may be formed.

Provided that at least one of R ₁ to R ₅ and at least one of Y ₁ or Y ₂ are bonded to form a ring, or at least one of R ₁ to R ₅ and at least one of R ₆ or R ₇ are bonded. To form a ring.
In addition, it may be bonded via a linking group at any position of R ₁ to R ₇ or at any position of Y ₁ or Y ₂ and may have two or more structures of the formula (PAG6).

Examples of the group formed by combining R ₆ and R ₇ include an alkylene group (preferably 4 to 10), and a butylene group, a pentylene group, and a hexylene group are preferable. In addition, the formed ring may have a substituent, and may contain a hetero atom in the ring skeleton.

The alkyl group represented by R _{1 to} R ₇ is a substituted or unsubstituted alkyl group, preferably an alkyl group having 1 to 5 carbon atoms. Examples of the unsubstituted alkyl group include a methyl group, an ethyl group, and a propyl group. Group, n-butyl group, sec-butyl group, t-butyl group and the like.
The alkoxy group in R _{1 to} R ₅ and the alkyloxycarbonyl group is a substituted or unsubstituted alkoxy group, preferably an alkoxy group having 1 to 5 carbon atoms. Methoxy group, ethoxy group, propoxy group, butoxy group and the like.
The aryl group of R _{1 to} R ₇ , Y ₁ , and Y ₂ is a substituted or unsubstituted aryl group, preferably an aryl group having 6 to 14 carbon atoms. As the unsubstituted aryl group, for example, phenyl Group, tolyl group, naphthyl group and the like.
Examples of the halogen atom represented by R _{1 to} R ₅ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group of Y ₁ and Y ₂ is a substituted or unsubstituted alkyl group, preferably an alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, Examples thereof include linear or branched alkyl groups such as sec-butyl group and t-butyl group.
The cycloalkyl group of Y ₁ and Y ₂ is a substituted or unsubstituted cycloalkyl group, preferably an alkyl group having 3 to 30 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group. And a cycloalkyl group such as a norbornyl group and a boronyl group.

The aralkyl group of Y ₁ and Y ₂ is a substituted or unsubstituted aralkyl group, preferably an aralkyl group having 7 to 12 carbon atoms. Examples of the unsubstituted aralkyl group include benzyl group, phenethyl group, cumyl group Groups and the like.

The aromatic group containing a hetero atom represents a group having a hetero atom, for example, a nitrogen atom, an oxygen atom, a sulfur atom, etc. in an aromatic group such as an aryl group having 6 to 14 carbon atoms.
The aromatic group containing a hetero atom of Y ₁ and Y ₂ is an aromatic group containing a substituted or unsubstituted hetero atom. Examples of the unsubstituted group include furan, thiophene, pyrrole, pyridine, and indole. And the heterocyclic aromatic hydrocarbon group.

Y ₁ and Y ₂ may combine to form a ring together with S ⁺ in formula (PAG6).
In this case, examples of the group formed by combining Y ₁ and Y ₂ include an alkylene group having 4 to 10 carbon atoms, preferably a butylene group, a pentylene group, and a hexylene group, and particularly preferably a butylene group and a pentylene group. Can be mentioned.
In addition, a ring formed by combining Y ₁ and Y ₂ together with S ⁺ in formula (PAG6) may contain a hetero atom.

  Each of the above alkyl group, alkoxy group, alkoxycarbonyl group, aryl group, aralkyl group and alkylene group is, for example, a nitro group, a halogen atom, a carboxyl group, a hydroxyl group, an amino group, a cyano group, or an alkoxy group (preferably having a carbon number). 1-5) and the like may be substituted. Further, the aryl group and aralkyl group may be substituted with an alkyl group (preferably having 1 to 5 carbon atoms).

Y ₃ represents a single bond or a divalent linking group, and examples of the divalent linking group include an optionally substituted alkylene group, alkenylene group, —O—, —S—, —CO—, —CONR—. (R is hydrogen, an alkyl group, or an acyl group.) And a linking group that may include two or more of these are preferable.

Z ⁻ is preferably a non-nucleophilic anion, and examples thereof include a sulfonate anion and a carboxylate 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 alkyl sulfonate anion, a cycloalkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion.
Examples of the carboxylic acid anion include an alkyl carboxylic acid anion, a cycloalkyl carboxylic acid anion, an aryl carboxylic acid anion, and an aralkyl carboxylic acid anion.

The alkyl group in the alkylsulfonate anion is preferably an alkyl group having 1 to 30 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, or a pentyl group. , Neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl be able to.
Preferred examples of the cycloalkyl group in the cycloalkyl sulfonate anion include an alkyl group having 1 to 30 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group.
The aryl group in the aryl sulfonate anion preferably has 6 to 14 carbon atoms.
Aryl groups such as a phenyl group, a tolyl group, and a naphthyl group.

The alkyl group, cycloalkyl group and aryl group in the alkyl sulfonate anion, cycloalkyl sulfonate anion and aryl sulfonate anion may have a substituent.
Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, and an alkylthio group.

Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.
As the alkyl group, for example, preferably an alkyl group having 1 to 15 carbon atoms, for example, 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, etc. it can.
As an alkoxy group, Preferably a C1-C5 alkoxy group, for example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned, for example.
As the alkylthio group, for example, preferably an alkylthio group having 1 to 15 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, an n-butylthio group, an isobutylthio group, a sec-butylthio group, a pentylthio group, Neopentylthio group, hexylthio group, heptylthio group, octylthio group, nonylthio group, decylthio group, undecylthio group, dodecylthio group, tridecylthio group, tetradecylthio group, pentadecylthio group, hexadecylthio group, heptadecylthio group, octadecylthio group, nonadecylthio group Group, eicosylthio group and the like. The alkyl group, alkoxy group, and alkylthio group may be further substituted with a halogen atom (preferably a fluorine atom).

Examples of the alkyl group in the alkylcarboxylate anion include the same alkyl groups as in the alkylsulfonate anion.
Examples of the cycloalkyl group in the cycloalkyl carboxylate anion include the same cycloalkyl groups as in the cycloalkyl sulfonate anion.
Examples of the cycloalkyl group in the cycloalkyl carboxylate anion include the same cycloalkyl groups as in the cycloalkyl sulfonate anion.
Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate anion.
The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the alkylcarboxylate anion, cycloalkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion may have a substituent. And the same halogen atom, alkyl group, alkoxy group, alkylthio group and the like as in the aryl sulfonate anion.

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

In the formula (PAG6) of the present invention, at least one of R ₁ to R ₅ and at least one of Y ₁ or Y ₂ are bonded to form a ring, or at least one of R ₁ to R ₅ At least one of R _{6 and} R ₇ is bonded to form a ring.
The compound represented by the formula (PAG6) has a three-dimensional structure and improves optical resolution by forming a ring.
In addition, it may be bonded via a linking group at any position of R ₁ to R ₇ , or any position of Y ₁ or Y ₂ , and may have two or more structures of the formula (PAG6).

  Specific examples of the compound represented by the above formula (PAG6) are shown below, but the present invention is not limited thereto.

It is preferable that the composition of this invention contains at least 1 sort (s) of the compound represented by general formula (PAG1), (PAG2), and (PAG6).
In the present invention, as a compound that generates an acid upon irradiation with an actinic ray or radiation, an onium salt compound represented by the general formula (PAG1) or (PAG2) and other non-onium salt compounds are used. It is preferable to use together.
In the present invention, it is preferable to use two or more compounds having different transmittances for exposure at a wavelength of 193 nm as a compound that generates an acid upon irradiation with actinic rays or radiation.
In the present invention, as the compound that generates an acid upon irradiation with actinic rays or radiation, it is preferable to use in combination two or more compounds having different carbon chain lengths of the acid generated upon irradiation with actinic rays or radiation.
In the present invention, it is preferable to use two or more kinds of compounds having different acid strengths generated by irradiation with actinic rays or radiation in combination as the compounds generating acid upon irradiation with actinic rays or radiation.

  In the specific example of the acid generator represented by the general formula (PAG6), (PAG6A-1) to (PAG6A-30) and (PAG6B-1) to (PAG6B-12) are more preferable.

  An acid generator can be used individually by 1 type or in combination of 2 or more types.

  The content of the acid generator in the positive resist composition of the present invention is preferably 0.1 to 20% by mass, more preferably 0.5 to 20% by mass, and still more preferably, based on the solid content of the composition. 1 to 15% by mass.

  Among the acid generators used in the present invention, examples of particularly preferable ones are listed below.

  In the present invention, the photoacid generator is particularly preferably a compound that generates perfluorobutanesulfonic acid or perfluorooctanesulfonic acid.

[3] Solvent (component D)
The resist composition of the present invention is obtained by dissolving the above-described components in a solvent.
Examples of the solvent include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene. Glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, Dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, 3-methoxy-1-butanol, and Organic solvent such as Russia pyrene carbonate. These solvents may be used alone or in combination.

In the present invention, in particular, at least two kinds selected from propylene glycol monoalkyl ether carboxylate, propylene glycol monoalkyl ether, linear or cyclic ketone, alkyl lactate, cyclic lactone, 3-methoxy-1-butanol, and propylene carbonate. It is preferable to use a mixed solvent containing.
In this specific mixed solvent, it is preferable to contain 3% by mass or more of each specific solvent.

[4] Nitrogen-containing basic compound The resist composition of the present invention preferably further contains a nitrogen-containing basic compound.
As the nitrogen-containing basic compound, an organic amine, a basic ammonium salt, a basic sulfonium salt, or the like is used, as long as it does not deteriorate sublimation or resist performance.
Among these nitrogen-containing basic compounds, organic amines are preferred because of excellent image performance.
For example, JP-A-63-149640, JP-A-5-249662, JP-A-5-127369, JP-A-5-289322, JP-A-5-249683, JP-A-5-289340, JP-A-5-232706 JP-A-5-257282, JP-A-62-242605, JP-A-6-242606, JP-A-6-266100, JP-A-6-266110, JP-A-6-317902, JP-A-7-120929, JP-A-7-65558, JP-A-7-319163, JP-A-7-508840, JP-A-7-333844, JP-A-7-219217, JP-A-7-92678, JP-A-7-28247, Special Kaihei 8-22120, JP-A-8110638, JP-A8-123030, JP-A-9-274312, JP-A-9-66871, JP-A-9-292708, JP-A-9-325496, Special table Basic compounds described in JP-A-7-508840, USP5525453, USP5629134, USP5667938 and the like can be used.

 Specific examples of the nitrogen-containing basic compound include structures of the following formulas (A) to (E).

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

The alkyl group, cycloalkyl group and aryl group of R ²⁵⁰ , R ²⁵¹ and R ²⁵² may have a substituent. Examples of the alkyl group and cycloalkyl group which may have a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 0 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and carbon. Examples thereof include a hydroxycycloalkyl group having a number of 3 to 20.

R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms.
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, or aliphatic tertiary amines.

As the nitrogen-containing basic compound, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo is preferable. [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidines, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, anilines, hydroxyalkylanilines, 4,4′-diamino Diphenyl ether, pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, and tetrabutylammonium lactate, triethylamine, tributylamine, tripentylamine, tri-n -Oct And ruamine, tri-i-octylamine, tris (ethylhexyl) amine, tridecylamine, and tridodecylamine.
Among these, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, 1-naphthylamine, piperidine, 4-hydroxypiperidine, 2,2,6,6-tetramethyl-4-hydroxypiperidine, hexamethylenetetramine, imidazoles, hydroxypyridines, pyridines, aniline Kind, 4
, 4'-diaminodiphenyl ether, triethylamine, tributylamine, tripentylamine, tri-n-octylamine, tris (ethylhexyl) amine, tridodecylamine, N, N-di-hydroxyethylaniline, N-hydroxyethyl-N- Organic amines such as ethylaniline are preferred.

  The use ratio of the acid generator and the nitrogen-containing basic compound in the positive resist composition is usually (acid generator) / (nitrogen-containing basic compound) (molar ratio) = 2.5 to 300, preferably Is 5.0 to 200, more preferably 7.0 to 150.

  In the positive resist composition of the present invention, a low-molecular acid-decomposable compound, a surfactant, a dissolution-promoting compound for a developer, an antihalation agent, a plasticizer, a photosensitizer, and a surfactant, if necessary. , An adhesion assistant, a crosslinking agent, a photobase generator, and the like can be contained.

The positive resist composition of the present invention has a low molecular acid decomposability, which has a molecular weight of 2000 or less, if necessary, has a group that can be decomposed by the action of an acid, and has increased alkali solubility by the action of an acid. A compound and a low molecular weight alicyclic compound can be included.
For example, Proc. SPIE, 2724, 355 (1996), JP-A-8-15865, U.S. Pat.No. 5310619, U.S. Pat.No. 5372912, J. Photopolym. Sci., Tech., Vol. 10, No. 3, 511 (1997) )) Containing an acid-decomposable group, an alicyclic compound such as a cholic acid derivative, a dehydrocholic acid derivative, a deoxycholic acid derivative, a lithocholic acid derivative, a ursocholic acid derivative, an abietic acid derivative, An aromatic compound such as a naphthalene derivative containing a group can be used as the low-molecular acid-decomposable compound.
Further, the low-molecular acid-decomposable dissolution inhibiting compounds described in JP-A-6-51519 can also be used in an addition range at a level that does not deteriorate the transmittance at 220 nm, and 1,2-naphthoquinone diazite compounds can also be used.

  As the alicyclic moiety possessed by the low molecular weight alicyclic compound, the alicyclic hydrocarbon group of the alicyclic hydrocarbon group has a repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pVI). (1) to (50) exemplified as the cyclic moiety can be mentioned. These alicyclic moieties may have a substituent, and examples of the substituent include an alkyl group (preferably 1 to 10 carbon atoms), a halogen atom, a hydroxyl group, a carboxyl group, and an alkoxy group.

When the low molecular acid decomposable dissolution inhibiting compound is used in the resist composition of the present invention, the content thereof is usually in the range of 0.5 to 50 parts by mass based on 100 parts by mass (solid content) of the resist composition. Preferably 0.5 to 40 parts by mass, more preferably 0.5 to 30 parts by mass, and particularly preferably 0.5 to 20.0 parts by mass.
When these low molecular acid decomposable dissolution inhibiting compounds and low molecular alicyclic compounds are added, not only the development defects are further improved, but also dry etching resistance is improved.

Examples of the dissolution promoting compound that can be used in the present invention include compounds containing two or more phenolic hydroxyl groups described in JP-A-3-206458, one naphthol such as 1-naphthol, or one carboxyl group. Examples thereof include low molecular compounds having a molecular weight of 1000 or less, such as compounds having the above, carboxylic acid anhydrides, sulfonamide compounds and sulfonylimide compounds.
The blending amount of these dissolution promoting compounds is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total mass (solid content) of the composition.

As a suitable antihalation agent, a compound that efficiently absorbs irradiated radiation is preferable, and substituted benzenes such as fluorene, 9-fluorenone, and benzophenone; anthracene, anthracene-9-methanol, anthracene-9-carboxyethyl, phenanthrene , Polycyclic aromatic compounds such as perylene and azylene. Of these, polycyclic aromatic compounds are particularly preferred. These antihalation agents exhibit the effect of improving standing waves by reducing the reflected light from the substrate and reducing the influence of multiple reflections in the resist film.

  Moreover, in order to improve the acid generation rate by exposure, a photosensitizer can be added. Suitable photosensitizers include benzophenone, p, p′-tetramethyldiaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, pyrene, phenothiazine, benzyl, benzoflavine, acetophenone, phenanthrene, benzoquinone, anthraquinone, 1 , 2-naphthoquinone and the like, but are not limited thereto. These photosensitizers can also be used as the antihalation agent.

The positive resist composition of the present invention comprises a surfactant, particularly a fluorine-based and / or silicon-based surfactant (a fluorine-based surfactant and a silicon-based surfactant, a surface activity containing both fluorine atoms and silicon atoms). It is preferable to contain any one of these, or two or more.
When the positive resist composition of the present invention contains a fluorine-based and / or silicon-based surfactant, adhesion and development defects are obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It is possible to provide a resist pattern with less.
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 EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, and 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). 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).

≪How to use≫
The positive resist composition of the present invention is used by dissolving the above components in a solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
That is, the positive resist composition is coated, dried or baked on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate coating method such as a spinner or a coater. A resist film is formed.
The resist film is exposed through a predetermined mask, preferably baked and developed. In this way, a good resist pattern can be obtained. Here, the exposure light is preferably far ultraviolet rays having a wavelength of 200 nm or less. Specifically, ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), radiation, electron beam, X-ray, ion beam, etc. Is mentioned.

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example. In the following synthesis examples, the ratio of solvents used in plural is a mass ratio, the monomer ratio, and the polymer composition ratio are molar ratios.

Synthesis Example (1) Synthesis of Resin (1-1) 2-Adamantyl-2-propyl methacrylate, dihydroxyadamantane methacrylate and norbornane lactone acrylate were charged at a ratio of 40/20/40, and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 was dissolved, and 450 g of a solution having a solid content concentration of 22% by mass was prepared. To this solution, 8 mol% of a polymerization initiator V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added.
The mixture was added dropwise to 50 g of a mixed solution of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 heated to 100 ° C. over time. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (1-1). did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 39/22/39. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 5190, and dispersion degree was 1.8. Moreover, as a result of measuring with the differential scanning calorimeter (DSC), the glass transition point of resin (1-1) was 152 degreeC.

Synthesis Example (2) Synthesis of Resin (1-2) 2-Adamantyl-2-propyl methacrylate, dihydroxyadamantane methacrylate and norbornane lactone acrylate were charged at a ratio of 40/20/40, and propylene glycol monomethyl ether acetate / 3-methoxy- It melt | dissolved in 1-butanol = 60/40, and 450 g of solutions with a solid content concentration of 22% were prepared. 8 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was heated to 120 ° C. over 6 hours in a nitrogen atmosphere, propylene glycol monomethyl ether acetate / 3-methoxy-1-butanol = 60 / It was dripped at 50 g of 40 mixed solutions. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (1-2). did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 36/23/41. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 3270, and dispersion degree was 1.5. Moreover, as a result of performing DSC measurement, the glass transition point of resin (1-2) was 119 degreeC.

Synthesis Example (3) Synthesis of Resin (1-3) 2-Adamantyl-2-propyl methacrylate, dihydroxyadamantane methacrylate and norbornane lactone acrylate were charged at a ratio of 40/20/40, and propylene glycol monomethyl ether acetate / 3-methoxy- It melt | dissolved in 1-butanol = 60/40, and 450 g of solutions with a solid content concentration of 22% were prepared. 6 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was heated to 120 ° C. over 6 hours in a nitrogen atmosphere, propylene glycol monomethyl ether acetate / 3-methoxy-1-butanol = 60 / It was dripped at 50 g of 40 mixed solutions. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (1-3). did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 36/23/41. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 4100, and dispersion degree was 1.6. Moreover, as a result of performing DSC measurement, the glass transition point of resin (1-3) was 139 degreeC.

Synthesis Example (4) Synthesis of Resin (1-4) 2-Adamantyl-2-propyl methacrylate, norbornane lactone acrylate, and dihydroxyadamantane methacrylate were charged at a ratio of 35/45/20, dissolved in THF solvent, and a solid content of 22 450 g of a% solution was prepared.
9 mol% of Wako Pure Chemical Industries, Ltd. V-601 was added to this solution, and this was dripped at 50 g of THF solvent heated at 65 degreeC over 6 hours in nitrogen atmosphere. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of heptane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to collect the resin (1-4) which was the target product.
The polymer composition ratio determined from NMR was 35/44/21. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 7700, and dispersion degree was 2.0. The obtained resin (1-4) had a glass transition temperature of 168 ° C.

Synthesis Example (5) Synthesis of Resin (1-5) 2-Adamantyl-2-propyl methacrylate, norbornane lactone acrylate and dihydroxyadamantane methacrylate were charged at a ratio of 35/45/20, and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 7/3 Dissolved in a mixed solvent to prepare 450 g of a solution having a solid concentration of 22%. 8 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was heated to 80 ° C. over 6 hours under a nitrogen atmosphere. Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 7/3 mixed solvent It was dripped at 50g. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of heptane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to collect the resin (1-5) which was the target product.
The polymer composition ratio determined from NMR was 35/44/21. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 8500, and dispersion degree was 2.0. The obtained resin (1-5) had a glass transition temperature of 183 ° C.

Synthesis Example (6) Synthesis of Resin (2-1) 2-Ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantane acrylate, and γ-lactone acrylate were charged at a ratio of 40/20/40, and propylene glycol monomethyl ether It melt | dissolved in acetate / propylene glycol monomethyl ether = 60/40 (mass ratio), and 450 g of solutions with a solid content concentration of 22 mass% were prepared. 1 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was heated to 100 ° C. over 6 hours in a nitrogen atmosphere, and a mixture of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 It was dripped at 50g of solutions. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1 (mass ratio), and the precipitated white powder was collected by filtration to obtain the target resin (2- 1) was recovered.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 35/27/28. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 9910, and dispersion degree was 2.2. Moreover, as a result of performing DSC measurement, the glass transition point of resin (2-1) was 122 degreeC.

Synthesis Example (7) Synthesis of Resin (3-1) Polymerization was performed in the same manner as in Synthesis Example (1) to obtain a target resin (3-1).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 30/22/39/9. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 5840, and dispersion degree was 1.7. Moreover, as a result of performing DSC measurement, the glass transition point of resin (3-1) was 152 degreeC.

Synthesis Example (8) Synthesis of Resin (3-2) Polymerization was performed in the same manner as in Synthesis Example (3) to obtain the desired resin (3-2).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 30/22/39/9. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 3890, and dispersion degree was 1.6. Moreover, as a result of performing DSC measurement, the glass transition point of resin (3-2) was 134 degreeC.

Synthesis Example (9) Synthesis of Resin (4-1) 2-Adamantyl-2-propyl methacrylate, 2-adamantyl-2-propyl acrylate, dihydroxyadamantane methacrylate and norbornane lactone acrylate were charged at a ratio of 20/20/20/40. Then, it was dissolved in propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 to prepare 450 g of a solution having a solid content concentration of 22%. 9 mol% of Wako Pure Chemical Industries, Ltd. V-601 was added to this solution, and this was heated to 80 ° C. over 6 hours in a nitrogen atmosphere, and a mixture of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 It was dripped at 50g of solutions. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the target resin (4-1). did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 20/20/21/39. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 7980, and dispersion degree was 2.3. Moreover, as a result of performing DSC measurement, the glass transition point of resin (4-1) was 155 degreeC.

Synthesis Example (10) Synthesis of Resin (4-2) 2-Adamantyl-2-propyl methacrylate, 2-adamantyl-2-propyl acrylate, dihydroxyadamantane methacrylate and norbornane lactone acrylate were charged at a ratio of 20/20/20/40. Then, it was dissolved in propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 to prepare 450 g of a solution having a solid content concentration of 22%. To this solution, 5 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added, and this was heated to 80 ° C. over 6 hours in a nitrogen atmosphere, and a mixture of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 It was dripped at 50g of solutions. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 9/1, the precipitated white powder was collected by filtration, and the target resin (4-2) was recovered. did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 20/20/21/39. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 9370, and dispersion degree was 2.2. Moreover, as a result of performing DSC measurement, the glass transition point of resin (4-2) was 161 degreeC.

Synthesis Example (11) Synthesis of Resin (5-1) Polymerization was performed in the same manner as in Synthesis Example (6) to obtain a target resin (5-1).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 37/19/2/42. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 8350, and dispersion degree was 2.1. Moreover, as a result of performing DSC measurement, the glass transition point of resin (5-1) was 156 degreeC.

Synthesis Example (12) Synthesis of Resin (5-2) Polymerization was performed in the same manner as in Synthesis Example (6) to obtain the desired resin (5-2).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 35/19/5/41. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 7630, and dispersion degree was 2.0. Moreover, as a result of performing DSC measurement, the glass transition point of resin (5-2) was 139 degreeC.

Synthesis Example (13) Synthesis of Resin (6-1) Polymerization was performed in the same manner as in Synthesis Example (6) to obtain the desired resin (6-1).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 39/16/40/5. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 8670, and dispersion degree was 2.2. Moreover, as a result of performing DSC measurement, the glass transition point of resin (6-1) was 147 degreeC.

Synthesis Example (14) Synthesis of Resin (7-1) Polymerization was performed in the same manner as in Synthesis Example (6) to obtain the desired resin (7-1).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c / d = 37/19/39/5. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 7560, and dispersion degree 1.9. Moreover, as a result of performing DSC measurement, the glass transition point of resin (7-1) was 139 degreeC.

Synthesis Example (15) Synthesis of Resin (8-1) 2-Ethyl-2-adamantyl acrylate, 3-hydroxy-1-adamantane acrylate and norbornane lactone acrylate were charged at a ratio of 40/20/40, and propylene glycol monomethyl ether acetate / Propylene glycol monomethyl ether = 60/40 to prepare 450 g of a solution having a solid content of 22%. To this solution, 1 mol% of V-601 manufactured by Wako Pure Chemical Industries, Ltd. was added dropwise to 50 g of a mixed solution of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60/40 heated to 80 ° C. over 6 hours in a nitrogen atmosphere. did. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of hexane / ethyl acetate = 10/1, and the precipitated white powder was collected by filtration to recover the target resin (8-1). did.
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 36/22/42. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 7900, and dispersion degree was 2.2. Moreover, as a result of performing DSC measurement, the glass transition point of resin (8-1) was 83 degreeC.

Synthesis Example (16) Synthesis of Resin (8-2) 10 g of the resin (8-1) was dissolved in 90 mL of tetrahydrofuran, and 80 mL of hexane was added to this solution while stirring. The precipitated white solid was collected by filtration to recover the target resin (8-2).
^The polymer composition ratio determined from ¹³ CNMR was a / b / c = 35/23/42. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 11540, and dispersion degree was 1.5. Moreover, as a result of performing DSC measurement, the glass transition point of resin (8-2) was 141 degreeC.

Synthesis Example (17) Synthesis of Resin (1-6) 2-Adamantyl-2-propyl methacrylate, norbornane lactone acrylate and dihydroxyadamantane methacrylate were charged at a ratio of 35/45/20, and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 7/3 Dissolved in a mixed solvent to prepare 450 g of a solution having a solid concentration of 22%. 9 mol% of Wako Pure Chemical Industries, Ltd. V-601 was added to this solution, and this was heated to 100 ° C. over 6 hours in a nitrogen atmosphere, and propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 7/3 mixed solvent It was dripped at 50g. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of a mixed solvent of heptane / ethyl acetate = 9/1, and the precipitated white powder was collected by filtration to recover the resin (1-6) which was the target product.
The polymer composition ratio determined from NMR was 36/22/42. Moreover, the standard polystyrene conversion weight average molecular weight calculated | required by GPC measurement was 6700, and dispersion degree was 1.9. The obtained resin (1-6) had a glass transition temperature of 183 ° C.

[Example 1]
50 parts by mass of the polymer of Synthesis Example 1-5 and 50 parts by mass of the polymer of Synthesis Example 1-1, 4.0 parts by mass of the photoacid generator PAG2-4, 0.25 parts by mass of the additive N-1, 0.7 parts by weight of surfactant W-1, 540 parts by weight of solvent SL-1 and 360 parts by weight of solvent SL-2 were mixed, sufficiently stirred and dissolved, and then filtered through a 0.1 μm filter. A resist solution was prepared.

  ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was spin-coated on the BareSi substrate as an antireflection film and heated on a hot plate at 205 ° C. for 60 seconds to form a 78 nm ARC29a film on the substrate. The resist solution prepared above was spin-coated on this substrate and heated on a hot plate at 115 ° C. for 60 seconds to form a 260 nm resist film. The wafer was exposed with an ArF scanner with NA = 0.75 (PAS5500 / 1100 manufactured by ASML) and then subjected to PEB treatment for 60 seconds on a 120 ° C. hot plate. Subsequently, development was performed with an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide for 30 seconds, rinsed with pure water for 15 seconds, and then the substrate was spin-dried to form a resist pattern (substrate A).

Substrates B and C on which resist patterns were formed in the same manner as substrate A, except that the PEB treatment temperature was changed to 115 ° C. and 125 ° C.
The formed line pattern is observed with a length-measuring SEM (Hitachi S9260), the exposure amount for reproducing the 100 nm line-and-space pattern (1: 1) formed on the substrate A is obtained, and the substrate B at this exposure amount is obtained. And the width of a 100 nm line and space pattern in C was measured.
With the exposure amount that reproduces the 100 nm line and space pattern (line: space = 1: 1) on the substrate A, the width on the substrate B and the width on the substrate C for the 100 nm line and space pattern (line: space = 1: 1) A value (nm / ° C.) obtained by dividing the width difference (nm) by the PEB temperature difference 10 (° C.) was used as an index of PEB temperature dependency.
As a result, the composition of Example 1 was 115 nm for the substrate B and 85 nm for the substrate C. Therefore, the PEB temperature dependency was (115−85) nm / 10 ° C. = 3 nm / ° C.

[Examples 2 to 11]
The compositions of Examples 2 to 11 shown in Table 2 were also evaluated in the same manner as in Example 1.
In addition, Examples 10 and 11 are reference examples by amending the claims.

[Comparative Examples 1-4]
The compositions of Comparative Examples 1 to 4 in Table 2 were also evaluated in the same manner as in Example 1.

[Evaluation results of PEB temperature dependence]
The evaluation results of the PEB temperature dependency for Examples 1 to 11 and Comparative Examples 1 to 4 are shown in Table 2 as follows.
A: Less than 5 nm / ° C. B: 5 nm / ° C. or more and less than 10 nm / ° C. C: 10 nm / ° C. or more

  The symbols for each component listed in Table 2 are as follows.

[Photoacid generator]

[Basic compounds]
N-1: 1,5-diazabicyclo [4.3.0] -5-nonene N-2: 1,8-diazabicyclo [5.4.0] -7-undecene N-3: 4-dimethylaminopyridine N -4: triphenylimidazole N-5: 2,6-diisopropylaniline N-6: tributylamine N-7: N, N-dibutylaniline N-8: N, N-diethanol aniline

[Surfactant]
W-1: Megafuck F176 (manufactured by Dainippon Ink & Chemicals, Inc.)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
W-3: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

〔solvent〕
SL-1: Propylene glycol monomethyl ether acetate SL-2: Propylene glycol monomethyl ether SL-3: 3-methoxy-1-butanol SL-4: Propylene carbonate SL-5: Cyclohexanone

  From the results in Table 2, it can be seen that the composition of the present invention has low PEB temperature dependency.

Claims (4)

A positive resist composition comprising two types of resins containing a group that decomposes by the action of an acid and increases solubility in an alkaline developer, and a compound that generates an acid upon irradiation with actinic rays or radiation,
Each of the two types of resins contains at least one of a repeating unit derived from an acrylic acid derivative monomer and a repeating unit derived from a methacrylic acid derivative monomer, and an alicyclic structure, and has a weight average molecular weight of 4500 to 4500 . A positive resist composition having a range of 9370, wherein the difference between the weight average molecular weights of the two kinds of resins is 2000 or more. The resin of at least one of the two kinds of resins contains at least one of a repeating unit represented by the general formula (A1) and a repeating unit represented by the general formula (A2). 2. The positive resist composition according to 1.

R represents a hydrogen atom, a hydroxyl group, a halogen atom or an alkyl group. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group or a urea group, or a combination of two or more groups. To express.
W ₁ represents an alkylene group. The positive resist composition according to claim 1 or 2, wherein at least one of the two kinds of resins contains a repeating unit represented by the following general formula (A3).

R ₃ and ₄ each independently represent a hydrogen atom or a methyl group.   A pattern forming method comprising: forming a resist film from the positive resist composition according to claim 1; and exposing and developing the resist film.