WO2006077705A1

WO2006077705A1 - Positive resist composition and method for forming resist pattern

Info

Publication number: WO2006077705A1
Application number: PCT/JP2005/023154
Authority: WO
Inventors: Yohei Kinoshita
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2005-01-18
Filing date: 2005-12-16
Publication date: 2006-07-27

Abstract

Disclosed is a positive resist composition having high resolution which enables to improve DOF. This composition contains a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) which generates an acid when exposed to light. The resin component (A) has at least one constitutional unit (a1) selected from those represented by the general formula (a1-01) below and the general formula (a1-02) below, and the acid generator component (B) is composed of an onium salt acid generator (B1) having a cation component represented by the general formula (b-1) below or an onium salt acid generator (B4) having an anion component represented by the general formula (b-3) or (b-4) below. In the formulae below, Y represents an alicyclic group; n represents 0 or an integer of 1-3; m represents 0 or 1; R represents a hydrogen atom, a lower alkyl group, a fluorine atom or a fluorinated lower alkyl group; R1 and R2 respectively represent a hydrogen atom or a lower alkyl group; R11 represents an alkyl group, an alkoxy group, a halogen atom or a hydroxyl group; R12 and R13 respectively represent an aryl group of an alkyl group; and n' represents 0 or an integer of 1-3.

Description

Specification

Positive resist composition and resist pattern forming method

Technical field

The present invention relates to a positive resist composition and a resist pattern forming method.

Background art

In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, miniaturization has rapidly progressed due to advances in lithography technology. As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, ultraviolet rays typified by g-line and i-line have been used in the past, but now KrF excimer laser (248nm) is the center of mass production, and ArF excimer laser (193nm) is mass-produced. It has begun to be introduced.

Such a resist for a short wavelength light source is required to have high resolution capable of reproducing a pattern with a fine dimension and high sensitivity to such a short wavelength light source. As one of the resists satisfying such conditions, a chemically amplified resist containing a base resin and an acid generator (PAG) that generates acid upon exposure is known. There are a positive type in which the alkali solubility in the part increases and a negative type in which the alkali solubility in the exposed part decreases.

[0003] There is an onium salt as a PAG used in a chemically amplified positive resist composition, and various types have been proposed so far. For example, Patent Document 1 listed below describes PAGs composed of triphenylsulfonium onium salts, and among them, fluorinated compounds such as triphenylsulfonium nonafluorobutanesulfonate (TPS-PFBS). Onium salt acid generators that use an alkyl sulfonate ion as an anion are the most commonly used.

Patent Document 1: Japanese Patent Laid-Open No. 2003-167347

Disclosure of the invention

Problems to be solved by the invention

[0004] By the way, it is important to improve the depth of focus (D0F) in order to realize a resist pattern with fine dimensions. It is not possible to improve DOF while achieving high resolution. It ’s not easy.

[0005] The present invention has been made in view of the above circumstances, and provides high resolution.

It is an object of the present invention to provide a positive resist composition capable of improving DOF and a method for forming a resist pattern.

Means for solving the problem

In order to achieve the above object, the present invention employs the following configuration.

The first aspect (aspect) of the present invention is a positive resist composition, which comprises a resin component (A) whose alkali solubility is increased by the action of an acid, and an acid generator that generates an acid upon exposure. Component (B), wherein the component (A) is a structural unit represented by the following general formula (al-01) and a structural unit represented by the following general formula (al-02)

[Chemical 1]

(a 1 -0 2)

Replacement paper (Rule 26) [In the above formula, Y represents an aliphatic ring S; n represents 0 or an integer of 1 to 3; m represents 0 or 1; and R each independently represents a hydrogen atom or a carbon number of 1 to 5] A lower alkyl group, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms; and R ² each independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. Group power consisting of

Replacement paper (Rule 26) At least one structural unit (al), and

The component (B) is represented by the following general formula (b-1)

[Chemical 2]

[Wherein, R represents an aralkyl group, an alkoxy group, a halogen atom, or a hydroxyl group, R 1 and R ¹³ each independently represents an optionally substituted aryl group or alkyl group, and n ′ represents 0 or an integer of 1 to 3 is represented. And an onium salt-based acid generator (B1) having a cation moiety represented by the formula:

[0007] The second aspect of the present invention includes a step of forming a resist film on a substrate using the positive resist composition of the first aspect of the present invention, a step of exposing the resist film, and A resist pattern forming method including a step of developing the resist film to form a resist pattern is provided.

[0008] A third aspect of the present invention is a positive resist composition comprising a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) which generates an acid upon exposure. The component (A) is a structural unit represented by the following general formula (al-01) and a structural unit represented by the following general formula (a 1 02)

[Chemical 3]

Difference paper (Rule 26) [In the above formula, Y represents an aliphatic cyclic group; n represents 0 or an integer of 1 to 3; m represents 0 or 1; and R independently represents a hydrogen atom or a carbon number of 1 to 5] Represents a lower alkyl group, a fluorine atom or a fluorinated lower alkynole group having 1 to 5 carbon atoms; R ¹ R ² independently represents a hydrogen atom or a carbon number :! Represents a lower alkyl group of ˜5. Has at least one structural unit (al) selected, and

The component (B) is represented by the following general formula (b-3) or (b-4)

[Chemical 4]

[Wherein X "represents a C 2-6 alkylene group in which at least one hydrogen atom is substituted with a fluorine atom; Υ", Ζ "each independently represents at least one hydrogen atom is fluorine. Represents an alkynole group having 1 to 10 carbon atoms substituted with an atom, and contains an onium salt-based acid generator (B1) having an anion moiety represented by the formula:

The fourth aspect of the present invention includes a step of forming a resist film on a substrate using the positive resist composition of the third aspect of the present invention, a step of exposing the resist film, and the resist film A resist pattern forming method including a step of developing the resist pattern to form a resist pattern

Replacement paper (Rule 26) is there.

[0010] According to the present invention, there are provided a positive resist composition and a resist pattern forming method capable of obtaining high resolution and improving D0F.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The "structural unit" in the claims and the specification means a monomer unit constituting a resin.

(Monomer unit).

The “structural unit derived from acrylate ester force” in the claims and the specification means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.

“A structural unit derived from an acrylate ester” refers to a structural unit in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with another substituent such as a halogen atom, an alkyl group, or a halogenated alkyl group. Acrylic ester in which a hydrogen atom is bonded to the carbon atom at the position.

In addition, in the “structural unit derived from an acrylate ester force”, the term “spot (a carbon atom at the platter)” refers to the carbon atom to which the carboxy group is bonded, unless otherwise specified. That is.

Further, the “alkyl group” includes a linear, cyclic or branched alkyl group unless otherwise specified.

The positive resist composition of the present invention contains the resin component (Α) (hereinafter sometimes referred to as the (Α) component) and an acid generator (hereinafter referred to as “acid generator”) that generates an acid upon irradiation (exposure) of radiation. (Β) component)).

Since the component (ii) has a structural unit (al) having an acid dissociable, dissolution inhibiting group, it is insoluble in alkali before exposure. When the acid generated from the component (B) by exposure acts, The inhibitory group is dissociated, and as a result, the entire component (A) is alkali-insoluble to alkali-soluble. Therefore, in the formation of a resist pattern, if selective exposure is performed on the resist, or if post-exposure heating (PEB) is performed in addition to exposure, the exposed portion turns to alkali-soluble, while the unexposed portion becomes alkaline. It remains insoluble and does not change A positive resist pattern can be formed by alkali development.

[0013] <(Eight) component>

[Unit (al)]

Component (A) is at least one structural unit selected from the group consisting of the structural unit represented by the general formula (al-01) and the structural unit represented by the general formula (al-02) (al )

The structural unit (al) is a structural unit derived from the acrylate force, and is bonded to the oxygen atom at the terminal of the carbonyloxy group (C (◯) —O—) derived from the carboxy group. It has a structure in which an (alkoxyalkyl group) type acid dissociable, dissolution inhibiting group [CO ^ R ² ) — ◯ — (CH ² ) Y] is bonded. Therefore, when acid acts, the acid dissociation property

2 n

The bond is cleaved between the dissolution inhibiting group and the terminal oxygen atom.

[0014] In the general formulas (al-01) and (al-02), R is a hydrogen atom, a lower alkyl group having carbon atoms:! To 5, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms. . The fluorinated lower alkyl group is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and any of them may be used, but it is preferable that all are fluorinated.

Preferred examples of the lower alkyl group as R include a methyl group, an ethyl group, a propyl group, an isopropyl group, an _n -butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. It is done. Industrially, a methyl group is preferable. The fluorinated lower alkyl group having 1 to 5 carbon atoms is preferably a trifluoromethyl group such as a trifluoromethyl group, a hexafluoroethyl group, a heptafluoropropyl group, or a nonafluorobutyl group. More preferred.

In the general formulas (al — 01) and (al — 02), R ¹ R ² is preferably at least one hydrogen atom, more preferably a hydrogen atom.

n is preferably 0 or 1, more preferably 0.

[0016] Y is an aliphatic cyclic group, which may or may not have a substituent on the ring skeleton.

Here, “aliphatic” in the claims and the specification means relative to aromatics. It is defined as a concept that means a group, a compound, or the like that does not have aromaticity. “Aliphatic cyclic group” means a monocyclic or polycyclic group having no aromaticity. The basic ring structure excluding the substituent of the “aliphatic cyclic group” in the present invention is not limited to a group consisting of carbon and hydrogen (hydrocarbon group). It is preferable that The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. A polycyclic group is preferred.

Specific examples of such an aliphatic cyclic group include a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Can be illustrated.

Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done.

Y is particularly preferably a group obtained by removing one or more hydrogen atoms from adamantane (which may have a substituent).

When the aliphatic cyclic group as Y has a substituent on the ring skeleton, the substituent is preferably a polar group, particularly in order to suppress pattern collapse. Specific examples of the polar group include a hydroxyl group, a carboxy group, a cyano group, and an oxygen atom (= o). Of these, an oxygen atom (= ◯) is preferable.

[0017] Specific examples of the structural unit represented by the general formula (al-01) are shown below.

[0018] [Chemical 5]

[] [

) t

[0020] Specific examples of the structural unit represented by the general formula (al-02) are shown below.

[0021] [Chemical 7]

S1S02i202TaT02 (aT02I-l

(ϊ) csοalι-

(i1-02-1§) (§1 -02-20) tel 02-21 (a1-i2-2 »

The structural unit (al) is selected from the group consisting of the structural unit represented by the general formula (al-01) and the structural unit represented by the general formula (al_02). Two or more species may be used.

The structural unit (al) preferably includes the structural unit represented by the general formula (al_01) from the viewpoint of resolution. The proportion of the structural unit represented by the general formula (al-01) in (al) is preferably 50 mol% or more, and more preferably 80 mol% or more. Most preferably, it is mol%. [0025] (A) the amount of the structural during component unit (al) is, (A) relative to all the structural units within the component, 1 0-80 Monore ^_0/0 force S Preferably, 20-70 Monore ^_0/0 force more preferably S, 25~50 Monore ^_0/0 force further good better record,. By setting it to the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit value or less, it is possible to balance with other structural units.

[0026] [Structural unit (a2)]

In addition to the structural unit (al), the component (A) preferably has a structural unit (a2) derived from an acrylate ester having a latathone-containing monocyclic or polycyclic group.

The lathetone-containing monocyclic or polycyclic group of the structural unit ( _a2 ) is used to enhance the adhesion of the resist film to the substrate or to have an affinity for the developer when the component (A) is used for forming the resist film. It is effective for improving the sex.

Here, the ratatone-containing monocyclic or polycyclic group refers to a cyclic group containing one ring (lataton ring) containing a -o-c (o) structure. The rataton ring is counted as the first ring, and when it is a lactone ring alone, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure.

As the structural unit (a2), any unit can be used without any particular limitation as long as it has both such a rataton structure (one O—C (O) —) and a cyclic group.

Specifically, examples of the latatatone-containing monocyclic group include groups in which one hydrogen atom has been removed from y-peptite latatatone. In addition, examples of the latathone-containing polycyclic group include groups in which a bicycloalkane, tricycloalkane or tetracycloalkane having a latathone ring is removed. In particular, a group obtained by removing one hydrogen atom from a latathone-containing tricycloalkane having the following structural formula is advantageous in that it is easily available industrially.

[0028] [Chemical 10]

[0029] More specifically, examples of the structural unit (a2) include structural units represented by the following general formulas (a2_ :!) to (a2_5).

[0030] [Chemical 11]

ia2-)

[Wherein, R is the same as defined above, R ′ each independently represents a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is 0 or 1. ]

In the general formulas (a2— :!) to (a2—5), the lower alkyl group for R ′ is the above structural unit.

It is the same as the lower alkyl group for R in (al) (at least one selected from general formulas (al—01) and (al—02)).

In general formulas (a2— :!) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

[0033] Specific structural units of the general formulas (a2— :!) to (a2-5) are exemplified.

[0034] [Chemical 12]

, 2-1 1, («2.4)

[0035] [Chemical 13]

[0036] [Chem. 14] 卜卜 vudiidiloo inch slc

t << ..

] Εοο

(a2-5-3) (a2- 5- 4)

As the structural unit (a2), it is preferable to use at least one selected from the general formulas (a2— :!) to (a2-5) general formulas (a2—l) to (a2-3) force selections It is more preferable to use one or more of these. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3-0) It is preferable to use one or more selected from (a2-3-9) and (a2-3-10).

Replacement paper (Rule 26) In component (A), as structural unit (a2), one type may be used alone, or two or more types may be used in combination.

When the structural unit (a2) is contained in the component (A), the content of the structural unit (a2) is preferably 10 to 80 mol% with respect to the total of all the structural units in the component (A). 50 Monore ^_0/0 and more preferably fixture 25 to 50 mol% is more preferred. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the upper limit it or less, it is possible to balance with other structural units.

Replacement paper (Rule 26) In the present invention, the component (A) is preferably a copolymer having the structural units (al) and (a2).

[0041] [Structural unit (a3)]

The structural unit (a3) is a structural unit other than the structural unit (al) and the structural unit (a2), includes an aliphatic cyclic group-containing non-acid dissociable, dissolution inhibiting group, and does not include a polar group. Acrylic ester force is a structural unit derived.

An aliphatic cyclic group-containing non-acid dissociable, dissolution inhibiting group is a group having an aromaticity, a cyclic group (aliphatic cyclic group), and generated from the component (B). This is a non-acid dissociable, dissolution inhibiting group that cannot be dissociated by acid. As the structural unit (a3), for example, a unit in which the aliphatic cyclic group-containing non-acid dissociable, dissolution inhibiting group is bonded to the ester portion of an acrylate ester can be mentioned.

That is, the structural unit (a3) reduces the alkali solubility of the entire component (A) before exposure, and is not dissociated by the action of an acid generated from the component (B) after exposure. ) Acid dissociable, dissolution-inhibiting group (A) When the entire component (A) is changed to alkali-soluble, the group (A) has a solubility-suppressing property that reduces the alkali-solubility of the entire component to the extent that it does not become insoluble in alkali. Is a structural unit including Therefore, the structural unit (a 3) has a function of suppressing the alkali solubility by increasing the hydrophobicity of the entire component (A) before and after exposure. Specifically, it is a structural unit that can improve (improve hydrophobicity) the contact angle for pure water rinse after PEB (post-exposure heat treatment).

In addition, the structural unit (a3) needs to contain no polar group. Here, the polar group includes a hydroxyl group, a cyano group, a carboxy group, a “hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group are replaced by fluorine atoms”, and the like.

The structural unit (a3) preferably does not contain an acid dissociable, dissolution inhibiting group.

The structural unit (a3) is preferably the following general formula (a3)

[0043] [Chemical 17]

[Wherein, R is the same as defined above. Z represents an aliphatic cyclic group having 4 to 15 carbon atoms in the basic ring, which may have 1 to 3 alkyl groups having 1 to 10 carbon atoms. ] Is a structural unit.

[0045] Z is an aliphatic cyclic group (which may be monocyclic or polycyclic) having 4 to 15 carbon atoms in the basic ring (ring structure excluding a substituent), and the aliphatic cyclic group The group is an alkyl group having 1 to 10 carbon atoms and 1 to 10

You may have three.

When Z has an alkyl group, the alkyl group is an alkyl group having 1 to 10 carbon atoms, and a linear or branched alkyl group having 1 to 5 carbon atoms is particularly preferable. Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, an isopentyl group, and a neopentyl group. In Z, the number of the alkyl group is preferably 0 or 1, and more preferably 0.

The structural unit (a3) does not overlap with the structural unit (al) and the structural unit (a2). That is, a specific acid dissociable, dissolution inhibiting group in the structural unit (al), and a rataton-containing group in the structural unit (a2), and the same group, and no deviation.

In the structural unit (a3), the cyclic group constituting the basic skeleton of the aliphatic cyclic group is a monocyclic or polycyclic aliphatic cyclic group conventionally known as an ArF positive resist material. It can be used.

Examples of the monocyclic aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclohexane or cyclopentane.

Examples of the polycyclic aliphatic cyclic group include groups in which one or two or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. Specific examples include groups in which one or two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Among these, a cyclohexyl group, a cyclopentyl group, an adamantyl group, a norbornyl group, an isobornyl group, a tricyclodecanyl group, and a tetracyclododecanyl group are preferred from the viewpoint of industrial availability.

The following general formulas (a3— :!) to (a3 — 5) are preferable examples as the structural unit (a3).

[0048] [Chemical 18]

[Wherein R is the same as defined above. ]

Among these, the structural unit represented by the general formula (a3_l) is preferable because the shape of the obtained resist pattern, for example, rectangularity is particularly good. Further, it is preferable from the viewpoint of suppressing pattern collapse. [0050] As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.

When component (A3) is included in component (A), the content of structural unit (a3) is preferably 3 to 50 mol% with respect to the total of all structural units of component (A). More preferred is 15-30 mol%. By setting the lower limit value or more, the effect of the present invention is excellent, and by setting the upper limit value or less, it is possible to balance with other structural units.

[0051] [Structural unit (a4)]

In addition to the structural units (al) to (a3), the component (A) further includes a structural unit (a4) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. It ’s okay. By having the structural unit (a4), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. To do. Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a “hydroxyalkyl group in which a part of the hydrogen atom of the alkyl group is substituted with a fluorine atom”, and a hydroxyl group is particularly preferable.

[0052] As the aliphatic hydrocarbon group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) or a polycyclic aliphatic hydrocarbon group (polycyclic group). ) Power S is mentioned. As the polycyclic group, for example, a resin for resist compositions for ArF excimer lasers, and many proposed ones can be appropriately selected and used.

Among them, a hydroxyl group, a cyano group, a carboxy group, or an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and an acrylate ester derivative is induced. The structural unit is more preferable. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Such polycyclic groups can be used by appropriately selecting from among many proposed polymers (resin components) for resist compositions for ArF excimerizers. Among these polycyclic groups, two or more hydrogen atoms are removed from adamantane and two or more hydrogen atoms are removed from norbornane. And a group obtained by removing two or more hydrogen atoms from tetracyclododecane is preferred industrially.

[0053] As the structural unit (a4), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the hydroxy group of acrylic acid is used. Preferred structural unit derived from tilester force When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a4-1), a structural unit represented by (a4-2), The structural unit represented by (a4-3) is preferred.

[0054] [Chemical 19]

(a4-3)

[0055] (wherein R is the same as above, j is an integer from:! To 3, k is an integer from 1 to 3, t 'is an integer from 1 to 3, and 1 is: ! ~ 5 is an integer, and s is an integer of 1 ~ 3 independently.)

[0056] In the formula (a4_l), j is preferably 1 or 2, and more preferably 1; When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0057] In the formula (a4_2), k is preferably 1. The Ciano group is the 5-position of the norbornyl group or

It is preferably bonded to the 6-position.

[0058] In the formula (a4-3), t 'is preferably 1. Les, preferably 1 is 1. Each s is preferably 1. Of these, 2-carboxyl at the end of the carboxy group of acrylic acid. A bornyl group or a 3_norbornyl group is preferred. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

[0059] As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.

When component (A) has structural unit (a4), the content of structural unit (a4) in component (A) is 5 to 50 mol% with respect to all structural units in component (A). it is preferably 15 to 45 Monore ^_0/0 to gesture et preferred, most preferably 15 to 35 Monore ^_0/0.

[0060] [Other structural units]

Further, in the positive photoresist composition of the present invention, as the component (A), the conventional chemical amplification type other than the structural units (al) to (a4) can be used as long as the effects of the present invention are not impaired. Used as a di-type resist for the production of acrylic acid derivatives, methacrylic acid derivatives, carboxylic acids having ethylenic double bonds to make them alkali-soluble, such as acrylic acid, metathallic acid, maleic acid, and fumaric acid, and acrylic resins The known monomers and the like can be used in combination as appropriate and copolymerized as necessary.

[0061] The component (A) is obtained, for example, by polymerizing a monomer related to each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIB N). be able to.

In addition, the component (A) contains, for example, HS—CH 2 —CH 2 —CH _C (CF

2 2 2

) By using a chain transfer agent such as _OH in combination, one terminal C (CF) -OH

3 2 3 2 groups may be introduced. In this way, copolymers introduced with hydroxyalkyl groups in which some of the hydrogen atoms in the alkyl group have been replaced with fluorine atoms reduce development defects and LER (Line Edge Roughness: uneven unevenness on the line sidewalls). ).

[0062] The mass average molecular weight (Mw) of the component (A) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but preferably 3000 to 50000, more preferably 3000 to 30000 force < 5,000 to 20000 most preferred.

When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good. Further, the dispersity (Mw / Mn) of the component (A) is preferably 1.0 to 5.0 force S, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0063] <Acid generator component (B)>

[(B1) component]

In the first and second embodiments of the present invention, the onion salt acid generator (B1) having a cation moiety represented by the general formula (b_l) is used as an essential component as the component (B). .

In the general formula (b-l), R ¹¹ represents an aralkyl group, an alkoxy group, a halogen atom, or a hydroxyl group, and n represents 0 or an integer of 1 to 3. When n ′ is 2 or 3, the plurality of R ¹¹ may be the same as or different from each other.

The alkyl group as R ¹¹ is most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group, preferably an alkyl group having 1 to 5 carbon atoms.

The alkoxy group as R ¹¹ is most preferably a methoxy group or an ethoxy group, preferably an alkoxy group having 1 to 5 carbon atoms.

The halogen atom as R ¹¹ is preferably a fluorine atom.

N ′ is preferably 0 or 1, more preferably 1.

In the general formula (b-l), R ¹² and R ¹³ each independently represents a substituent, aryl group or alkyl group, although they may have a substituent.

The aryl group as R ¹² and R ¹³ is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms, and the aryl group has an alkyl group, an alkoxy group, a part or all of the hydrogen atoms of which are It may not be substituted with a halogen atom, a hydroxyl group or the like. As the aryl group, an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.

When the hydrogen atom of the aryl group is substituted, the alkyl group as the substituent is the same as the alkyl group as R ¹¹ .

When the hydrogen atom of the aryl group is substituted, the alkoxy group as the substituent is the same as the alkoxy group as R ¹¹ .

A halogen atom as the substituent when the hydrogen atom of the aryl group is substituted; The child is the same as the halogen atom as R ¹¹ .

The alkyl group as ² and R ¹³ is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. From the viewpoint of excellent resolution, it is preferable that the carbon number is 1 to 5. Specifically, a methinore group, an ethyl group, an n-propyl group, an isopropyl group, an n_butyl group, an isobutyl group, an n_pentyl group, a cyclopentyl group, a hexinole group, a cyclohexinole group, a noninore group, a decanyl group A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost. Most preferably, the ² and R ¹³ are both phenyl groups.

[0065] The anion part in the component (B1) is not particularly limited, and what is known as an anion part of an onion salt-based acid generator can be appropriately used.

For example, the general formula "R ^M S_〇 ^_ (R ¹⁴ is a linear, branched or cyclic alkyl group or fluorinated

Three

Represents an alkylated alkyl group. ) ”, An anion part represented by the following general formula (b-3), an anion part represented by the following general formula (b-4), and the like can be used.

[0066] [Chemical 20]

[0067] [wherein X "represents a C 2-6 alkylene group in which at least one hydrogen atom is substituted with a fluorine atom; Υ", Ζ "each independently represents at least one hydrogen Represents an alkyl group having 1 to 10 carbon atoms in which the atom is substituted with a fluorine atom.]

[0068] In the general formula "R ^M S_〇" j, R ^M is also linear, branched or cyclic alkyl group

Three

Represents a fluorinated alkyl group.

The linear or branched alkyl group as R ¹⁴ has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. preferable. The cyclic alkyl group as R ¹⁴ is the cyclic alkyl group shown as ² or R ¹³ , and preferably has 4 to 15 carbon atoms, preferably 4 to 10 carbon atoms. Even better Most preferably, it is 6 to 10 carbon atoms.

Most preferably, the fluorinated alkyl group as R ¹⁴ has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Also. The fluorination rate of the fluorinated alkyl group (ratio of the number of fluorine atoms substituted by fluorination to the total number of hydrogen atoms in the alkyl group before fluorination, the same shall apply hereinafter) is preferably 10 to 100% More preferably, it is 50 to 100%, and in particular, all hydrogen atoms replaced with fluorine atoms are preferred because the strength of the acid becomes strong.

R ¹⁴ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In the general formula (b-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is replaced with a fluorine atom, and the alkylene group has 2 carbon atoms. -6, preferably 3-5 carbon atoms, most preferably 3 carbon atoms.

In the general formula (b-4), Y ″ and Ζ ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group The number of carbons is 1 to: 10, preferably the number of carbons:! To 7, more preferably 1 to 3.

The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of “アルキル” and “Ζ” is preferably as small as possible within the range of the above-mentioned carbon number for reasons such as good solubility in a resist solvent.

In addition, in the alkylene group of X "or the alkyl group of Υ" and Ζ ", the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. .

[0070] As the anion part of the component (B1), an anion part represented by the general formula (b_3) is preferable. X "is more preferably a perfluoroalkylene group.

[0071] Preferred specific examples of the component (B1) are listed below.

[0072] [Chemical 21]

Among these, the acid generator represented by the chemical formula (bl-07) or (bl-08) is particularly preferable.

As the component (B1), any of four types may be used. Two or more types may be used in combination.

The proportion of the component (B1) in the total component (B) is preferably 50% by mass or more. A more preferable range is 60 to 90% by mass, and 70 to 85% by mass is most preferable.

[0074] [(B2) component]

The component (B) preferably contains an acid generator (B2) represented by the following general formula (b-2) in addition to the component (B1). The component (B2) does not overlap with the component (B1). That is, the cation part of the component (B2) does not have “substituent, may, or naphthyl group”.

[0075] [Chemical 22]

[In the formula, R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; 1 ^ ″ to 1 ³ ″ may each independently have a substituent. Represents a good aryl group or an alkyl group, and at least one of 1 ^ "to" represents an aryl group.]

In the formula (b_ 2), 1 ^ "to 1 ^" each independently represents an aryl group or an alkyl group which may have a substituent. However! ^ ^{1 When} ”~! ^” Is an aryl group, the naphthyl group is excluded.

Of the scale ¹ "~! ^ ³ ", at least one represents an Aryl group. Of shaku ¹ "~! ^ ³ ", 2 or more are preferably aryl groups! It is most preferred that all of ^ ¹ "~! ^ ³ " be Aryl.

The aryl group as “˜” is not particularly limited as long as it is other than a naphthyl group. For example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl. It may or may not be substituted with a group, an alkoxy group, a halogen atom, or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at low cost. Specifically, a phenyl group is mentioned, for example.

The alkyl group as a substituent of the hydrogen atom of the aryl group is a methinole group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, which is preferably an alkyl group having from 5 to 5 carbon atoms. Most preferred.

The alkoxy group as a substituent for the hydrogen atom of the aryl group is most preferably a methoxy group or an ethoxy group, preferably an alkoxy group having from 5 to 5 carbon atoms.

The halogen atom as a substituent for the hydrogen atom of the aryl group is preferably a fluorine atom.

[0078] The alkyl group as ^ "~" is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups having carbon numbers:! -10. From the viewpoint of excellent resolution, it is preferably 1 to 5 carbon atoms. Specifically, methylol group, ethyl group, n-propyl group, isop Lopinole group, n_butyl group, isobutyl group, n_pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, noninole group, decanyl group, etc. are listed, and it has excellent resolution and can be synthesized at low cost. Among them, a methyl group can be mentioned as a preferred one.

Of these, it is most preferable that 1 ^ "to 1 ³ " are all phenyl groups.

[0079] R ⁴ "represents a linear, branched or cyclic alkyl group or fluorinated alkyl group.

The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.

The cyclic alkyl group is a cyclic group as indicated by R ¹ ″, and preferably has 4 to 10 carbon atoms, more preferably 4 to 10 carbon atoms. Most preferably, it has 6 to 10 carbon atoms.

The fluorinated alkyl group is most preferably 1 to 4 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 4 carbon atoms. Also. The fluorination rate of the fluorinated alkyl group is preferably 10 to 100%, more preferably 50 to 100%. In particular, the one in which all hydrogen atoms are substituted with fluorine atoms has a strong acid strength. This is preferable.

R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

[0080] Specific examples of the component (B2) include trifluoromethane sulfonate of triphenylsulfone, heptafluoropropane sulfonate or nonafluorobutane sulfonate, tri (4-methylphenol). Nole) trifluoromethanesulfonate of sulfone, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluorolone methanesulfonate of monophenyldimethylsulfone, its heptafluoropropane sulfonate or its nona Fluorobutanesulfonate, diphenylmonomethylsulfonyl trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, (4-methylphenyl) diphenyl Trifanoleomethane sulphonate, its hepta-fluoro-propanes sulphonate or its nonafluorobutane sulphonate, (4-methoxyphenyl) diphenyls-norephonium trif- ureol- methanes-sulphonate, its hepta-fluoro-sulphonate Propane Snow Leone Or its nonafluorobutane sulfonate, tri (4-tert-butynole) phenyl sulfone, trifluoromethane sulfonate, heptafluoropropane sulfonate, or nonafluorobutane sulfonate. Further, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can be used.

[0081] As the component (B2), any of four types of forces may be used, or two or more types may be used in combination.

When the component (B2) is used, the proportion of the component (B2) in the total component (B) is preferably 10 to 40% by mass, and 15 to 30% by mass is more preferably 15 to 25% by mass. Is most preferred.

[0082] [Other acid generators (B3)]

The component (B) further contains a known acid generator (hereinafter sometimes referred to as other acid generator (B3)) used in a chemically amplified resist composition. However, for the effect of the present invention, it is preferable that the total ratio of the component (B1) and the component (B2) in the whole component (B) is 80% by mass or more. Is more preferable.

[0083] Other acid generators (B3) include onium salt acid generators (B1) and (B2) other than the above-mentioned acid salt acid generators (for example, odonium salts), and oxime sulfonate acid generators. Lj, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes and other diazomethane acid generators, nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, disulfone Known acid generators such as acid generators can be used as appropriate.

Other acid generators (B3) may be used alone or in combination of two or more.

[0084] [(B4) component]

In the third and fourth aspects of the present invention, an onium salt acid generator (B4) having an anion moiety represented by the general formula (b_3) or (b-4) as the component (B) Is used as an essential ingredient.

In the general formula (b_3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is replaced with a fluorine atom, and the alkylene group has 2 to 2 carbon atoms. 6, preferably 3 to 5 carbon atoms, most preferably 3 carbon atoms.

In the general formula (b_4), Y ″ and Ζ ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the number of carbon atoms of the alkyl group Is 1 to: 10, preferably carbon numbers:! To 7, more preferably 1 to 3 carbon atoms.

[0085] As the anion part of the component (Β4), an anion part represented by the general formula (b-3) is preferable. X "is more preferably a perfluoroalkylene group.

[0086] The cation moiety in the component (B4) is not particularly limited, and what is known as an anion moiety of an onion salt-based acid generator can be appropriately used.

Among them, the ability to have a cation moiety represented by the following general formula (b_11) or (b_12) is preferable.

[0087] [Chemical 23]

[Wherein, R ⁿ to R ^lj and R ^{15 to} R ¹⁶ each independently represent an aryl group or an alkyl group; at least one of R ″ to R ¹³ represents an aryl group, R ^{15 to} R ^At least one of ¹⁶ represents an aryl group.]

In the formula (B-1), R ″ to R ¹³ each independently represents an aryl group or an alkyl group. Among these, at least one represents an aryl group. Of RU to R ^ld , two or more are preferably aryl groups. Most preferably, all of R ^{U to} R ¹³ are aryl groups. .

The aryl group of RU R ¹³ is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups, halogen atoms. It does not need to be substituted with an atom or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at low cost. Specific examples include a phenyl group and a naphthyl group. It is most preferable that at least one of the aryl groups of R ^m ″ to R ¹³ is a naphthyl group. By using a naphthyl group, the transparency to ArF excimer laser light is improved and resolution is improved. The alkyl group in which the hydrogen atom of the aryl group may be substituted is preferably a methyl group, an ethyl group or a propyl group, preferably an alkyl group having 1 to 5 carbon atoms. The n-butyl group and the tert-butyl group are most preferred, and the alkoxy group optionally substituted with a hydrogen atom in the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms. A methoxy group and an ethoxy group are most preferred, and the halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

The alkyl group of RUR ¹³ is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. From the viewpoint of excellent resolution, it is preferably 1 to 5 carbon atoms. Specifically, methylol group, ethyl group, n-propyl group, isopropylinole group, n_butyl group, isobutyl group, n_pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, noninole group, decanyl Groups, and the like, and is preferable because it is excellent in resolution and can be synthesized at low cost.

In formula (b_12), R ^{15 to} R ¹⁶ each independently represents an aryl group or an alkyl group.

At least one of R ^{15 to} R ¹⁶ represents an aryl group. All of R ^{15 to} R ¹⁶ are preferably aryl groups.

Examples of the aryl group of R ^{15 to} R ¹⁶ include those similar to the aryl group of R ″ to R ^13. Examples of the alkyl group of R ^{15 to} R ¹⁶ include those similar to the alkyl group of R ″ to R ^13. Is mentioned. Of these, it is most preferred that R ^{15 to} R ¹⁶ are all phenyl groups.

[0090] Specific preferred examples of the component (B4) are shown below. [0091] [Chemical 24]

[0092] Among these, the acid generator represented by the chemical formula (B1-07) or (B108) is particularly preferable.

Component (B4) can be used with 4 types of displacement and displacement force, or 2 or more types can be used together.

The proportion of the component (B4) in the total component (B) of the third embodiment is preferably 50% by mass or more, and may be 100% by mass. A more preferable range is 60 to 90% by mass, and 70 to 85% by mass is most preferable.

[0093] [Component (B5)]

The component (B) of the third embodiment preferably contains an acid generator (B5) represented by the following general formula (b-20) in addition to the component (B4).

[0094] [Chemical 25]

R ² -S ⁺ R ^M S03 ... 20)

[0095] [wherein R ⁴ ,, are linear, branched or cyclic alkyl groups or fluorinated alkyl groups; 1 ^ ′ ″ to 1 ³ ′ ″ are each independently substituted Represents an aryl group or an alkyl group which may have a group, and at least one of R ¹ ′ ″ to R ³ ′ ″ represents an aryl group.]

In formula (b_20), R ¹ ′ ′ ′ to R ³ ′ ′ ′ each independently represents an aryl group or an alkyl group which may have a substituent. At least one of R ¹ '''to R ³ ' To express. Of R ¹ '''to R ³ ''', it is preferred that 2 or more are aryl groups. Most preferably, all of R ¹ '"to R ³ ''' are aryl groups.

The aryl group as R ¹ ′ ″ to R ³ ′ ′ ′ is, for example, an aryl group having 6 to 20 carbon atoms, and the aryl group is an alkyl group, an alkoxy group, a part or all of the hydrogen atoms of which are It may or may not be substituted with a halogen atom, etc. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at low cost. Examples of the alkyl group as a substituent of the hydrogen atom of the aryl group include a methyl group, an ethyl group, a propyl group, and an alkyl group having 1 to 5 carbon atoms. Most preferred is an n-butyl group or a tert-butyl group, and the alkoxy group as a substituent for the hydrogen atom of the aryl group is preferably a methoxy group or an ethoxy group, preferably an alkoxy group having 1 to 5 carbon atoms. Most preferred is the water based on the aryl. Halogen atom as a substituent of atoms are Shi preferred that a fluorine atom.

[0097] The alkyl groups as R ¹ '"to R ³ ''' are not particularly limited, and examples thereof include straight chain, branched or cyclic alkyl groups having carbon numbers:! To 10 and the like. From the point of being excellent, the carbon number is preferably 1 to 5. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, cyclopentyl group And a hexynole group, a cyclohexenole group, a nonyl group, a decanyl group, and the like, which are excellent in resolution and can be synthesized at a low cost. R ¹ ′ ′ ′ to R ³ ′, are most preferably all phenyl groups.

[0098] R ⁴ ', represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.

The cyclic alkyl group is a cyclic group as indicated by R ¹ ′ ′ ′, preferably having 4 to 15 carbon atoms, and more preferably 4 to 10 carbon atoms. Most preferably, it has 6 to 10 carbon atoms.

The fluorinated alkyl group is most preferably 1 to 4 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. Also. The fluorination rate of the fluorine alkyl group is preferably 10 to 100%, more preferably 50 to 100%. In particular, those in which all of the hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid is increased.

R ⁴ '''is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

[0099] Specific examples of the component (B5) include trifluoromethane sulfonate of triphenylsulfone, heptafluoropropane sulfonate or nonafluorobutane sulfonate, tri (4-methylphenol). Nole) trifluoromethanesulfonate of sulfone, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluorolone methanesulfonate of monophenyldimethylsulfone, its heptafluoropropane sulfonate or its nona Fluorobutane sulfonate, diphenyl monomethylenolesnorephonium trifanololeomethane sulphonate, its heptafluororeopropane sulphonate or its nonafluorobutane sulphonate, (4 methylphenyl) diphenyl sulno Honium's trifanoloremethane sulphonate, its hepta-fluoro-propanes sulphonate or its nonafluorobutane sulphonate, (4-methoxyphenyl) diphenyls-norrephonium's tris-fluoro-methanes sulphonate, its hepta-fluoros Ropropane sulphonate or its nonafluorobutane sulfonate, tri (4 tert butyl) phenyl sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate Can be mentioned. Further, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can be used.

[0100] As the component (B5), any of four types may be used. Two or more types may be used in combination.

When the component (B5) is used, the proportion of the component (B5) in the whole component (B) is preferably 10 to 40% by mass, and 15 to 30% by mass is more preferably 15 to 25% by mass. Is most preferred.

[0101] [Other acid generators (B6)]

The component (B) of the third aspect of the present invention is a known acid generator (hereinafter referred to as other acid generator (B6) used in conventional chemically amplified resist compositions. ) And les may be contained), but for the effect of the present invention, the component (B4) in the whole component (B) And the total proportion of the components (B5) is preferably 80% by mass or more, more preferably 100% by mass.

[0102] Other acid generators (B6) include onium salt acid generators (B4) and (B5) other than the above-mentioned onium salt acid generators (eg, odonium salts), and oxime sulfonate acid generators. 1J, diazomethane acid generators such as bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, disulfone Known acid generators such as acid generators can be used as appropriate.

Other acid generators (B6) may be used alone or in combination of two or more.

[0103] The content of the component (B) in the positive resist composition of the present invention is preferably 2 to 20 parts by mass with respect to 100 parts by mass of the component (A) 5 to 15 parts by mass is more preferable. 5 to 13 parts by mass is most preferable. By setting it within the above range, pattern formation is sufficiently performed and good characteristics can be obtained. In addition, it is preferable because a uniform solution can be obtained and storage stability is improved.

[0104] <Nitrogen-containing organic compound (D)>

The positive resist composition of the present invention further includes a resist pattern shape, a post-image stability of the latent image for the a by the pattern-wise exposure of the resist layer, and the like. A nitrogen-containing organic compound (D) can be blended as an optional component.

A wide variety of components (D) have already been proposed, and any known one may be used. However, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred. .

Aliphatic amines contain at least one hydrogen atom of ammonia NH and have 12 or more carbon atoms.

Three

Examples include amines substituted with an alkyl group or hydroxyalkyl group below (alkylamines or alkylalcoholamines). Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; jetylamine, di-n-propylamine, di-n-heptylamine, di- _n—dialkylamines such as octylamine, dicyclohexylamine; trimethylamine, triethnoreamine, tri_n-propylamine, tri_n-butynoleamine, tri-n_hexylamine, tri-n-pentylamine, tri-n- Trialkylamines such as heptylamine, tri-n-octylamine, tri-n_noninoleamine, tri_n-decanylamine, tri_n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di_n Examples thereof include alkyl alcohol amines such as _octanolamine and tri-n-octanolamine. Of these, alkyl alcoholamines are preferred, with alkyl alcoholamines and trialkylamines being preferred. Of the alkyl alcoholamines, triethanolamine is most preferably triisopropanolamine.

These can be used alone or in combination of two or more.

Component (D) is usually used in the range of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

<(E) component>

In addition, the positive resist composition of the present invention prevents the deterioration of sensitivity due to the blending of the component (D), and the resist pattern shape and stability over time (post exposure stability of the latent image formed oy the pattern-wise). For the purpose of improving the exposure of the resist layer and the like, an organic carboxylic acid or phosphorus oxoacid or derivative thereof) (referred to as component (E) in this specification) can be added as an optional component. In addition, the component (D) and the component (E) can be used in combination, or one kind of force can be used.

As the organic carboxylic acid, for example, malonic acid, citrate, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.

Phosphoric acid or its derivatives include phosphoric acid, phosphoric acid di_n_butyl ester, phosphoric acid diphenyl ester, and the like, derivatives such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid. Phosphoric acid and its derivatives such as phosphonic acid, phenylphosphinic acid such as phosphonic acid, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester, etc. And derivatives such as those esters. Especially preferred is phosphonic acid.

Component (E) is used at a ratio of 0.0 :! to 5.0 parts by mass per 100 parts by mass of component (A).

[0106] <Organic solvent>

The positive resist composition of the present invention can be produced by dissolving the material in an organic solvent.

As the organic solvent, it is sufficient if it can dissolve each component to be used to make a uniform solution. These can be appropriately selected and used.

For example, latones such as γ-butyrolatatatone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monomono Polyhydric alcohols such as acetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, or monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether of dipropylene glycol monoacetate and derivatives thereof; Cyclic esters such as: methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, pyruvin Echiru, methyl methoxypropionate, and esters such as ethoxy propyl propionic acid Echiru can be exemplified.

These organic solvents may be used alone or as a mixed solvent of two or more.

A mixed solvent obtained by mixing propylene glycol monomethyl ether acetate (PGMEA) and a polar solvent is preferable. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, but is preferably 1: 9 to 9: 1, more preferably 2

: It is preferable to be in the range of 8 to 8: 2.

More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2.

In addition, as an organic solvent, in addition, at least selected from PGMEA and EL

A mixed solvent of one kind and γ_petit-mouthed rataton is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5. The amount of the organic solvent used is not particularly limited, but is a concentration that can be applied to a substrate and the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 to 20%. It is used so that it may fall within the range of 5% by mass, preferably 5 to 15% by mass.

[0108] <Other optional components>

The positive resist composition of the present invention may further contain, if desired, miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, and a dissolution inhibitor. Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be appropriately added and contained.

[0109] <Resist pattern formation method>

The resist pattern forming method of the present invention can be performed, for example, as follows. That is, first, the positive resist composition (the positive resist composition of the first or third embodiment) is applied onto a substrate such as a silicon wafer with a spinner or the like, and a temperature condition of 80 to 150 ° C. is applied. Then, a pre-beta is applied for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film.

Next, the resist film is selectively exposed with a single ArF excimer laser beam through a desired mask pattern using, for example, an ArF exposure apparatus or the like, and then subjected to PEB (after exposure at a temperature of 80 to 150 ° C. (Heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds.

Next, this is developed with an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide. If necessary, post-beta may be applied after development processing.

In this way, a resist pattern faithful to the mask pattern can be obtained.

An organic or inorganic antireflection layer can be provided between the substrate and the coating layer of the resist composition.

[0110] The wavelength used for the exposure is not particularly limited, ArF excimer laser, KrF excimer laser, F excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam),

2

It can be performed using radiation such as X-rays and soft X-rays. In particular, the positive resist composition according to the present invention is effective for an ArF excimer laser.

[0111] According to the positive resist composition of the present invention, high resolution can be obtained and DOF can be improved. Can be raised. In addition, the resist pattern is less likely to fall and the exposure margin can be improved. The reason is not clear, but is presumed as follows.

In the first aspect of the present invention, the component (B1), which is an essential component of the positive resist composition, has a substituent derived from naphthalene in the cation part, and therefore, a triphenylsulfonium-based onium salt. Compared with the acid generator component comprising, the light absorption in the exposure wavelength band is suppressed, and in particular, the light absorption is effectively suppressed in the wavelength band of the ArF excimer laser (especially for ArF excimer laser light). It is estimated that transparency will improve. Therefore, if the exposure amount is the same, the acid generation amount per mole of the acid generator component can be suppressed, and the variation of the acid generation amount relative to the variation of the exposure amount is considered to be relatively small.

The structural unit (al) of the component (A) has an acetal group (alkoxyalkyl group) type acid dissociable, dissolution inhibiting group. Since the deprotection energy of the acid dissociable, dissolution inhibiting group of the acetal group type is lower than that of the tertiary ester type acid dissociable, dissolution inhibiting group, the structural unit (al) is It is presumed that the acid dissociable, dissolution inhibiting group can be eliminated to increase alkali solubility and resolve fine patterns. In addition, it is considered that the allowable range of the amount of acid generation for obtaining good resolution is relatively wide.

In the first aspect of the present invention, the combination of the powerful component (B1) and the component (A) can be used to achieve both high resolution and improved DOF due to the synergistic effect of both. Therefore, it is considered that the above-described multiple good characteristics can be achieved simultaneously.

In the third aspect of the present invention, the component (B4), which is an essential component of the positive resist composition, has a skeleton represented by the general formula (b_3) or (b_4) in the anion portion. The acid diffusion length is expected to be shorter than that of the acid generator component comprising an onium salt having a fluorinated alkyl sulfonate ion as an anion. The structural unit (al) of the component (A) has an acetal group (alkoxyalkyl group) type acid dissociable, dissolution inhibiting group. Since the deprotection energy of the acid dissociable, dissolution inhibiting group of the acetal group type is lower than that of the tertiary ester type, acid dissociable, dissolution inhibiting group, the structural unit (al) has a low acid strength. It is presumed that the acid dissociable, dissolution inhibiting group can be eliminated to increase alkali solubility and resolve a fine pattern. In the third aspect of the present invention, by combining the powerful component (B4) and component (A), it is possible to achieve both high resolution and improved DOF due to their synergistic effects. Therefore, it is considered that the above-described multiple good characteristics can be achieved at the same time.

Example

[0113] [Synthesis Example 1] Synthesis of (2-adamantyloxymethyl) metatalylate

6.9 g of methacrylic acid was dissolved in 200 mL of tetrahydrofuran and triethylenamine 8. Og was added. After stirring at room temperature, lOOmL of tetrahydrofuran in which 15 g of 2-adamantyl chloromethyl ether was dissolved was added dropwise. After stirring at room temperature for 12 hours, the precipitated salt was filtered off. The obtained filtrate was evaporated, dissolved in 200 mL of ethyl acetate, washed with pure water (100 mLX3), and evaporated. A white solid was obtained after standing under ice cooling.

The obtained compound 1 ((2-adamantoxymethyl) metatalylate) is represented by the following chemical formula.

The results of measurement of infrared absorption spectrum (IR) and proton nuclear magnetic resonance spectrum (H-NMR) are shown.

IR (cm—: 2907, 2854 (C—H stretch), 1725 (C = 〇 stretch), 1638 (C = C stretch) 'H-NMRCCDCl, internal standard: tetramethylsilane) ppm: l.45-2. 1 (m, 17H)

Three

3.75 (s, 1H), 5.45 (s, 2H), 5.6 (s, 1H), 6.12 (s, 1H)

[0114] [Chemical 26]

[0115] [Synthesis Example 2] Synthesis of resin component (Al) 200 ml of 20.0 g of (2-adamantyloxymethyl) metatalylate obtained in Synthesis Example 1 above, 13.6 g of y-butyrolatatone methacrylate (GBLMA), and 8.8 g of tricyclodecanyl methacrylate After dissolving in tetrahydrofuran, 1.64 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 1 L of n-heptane. The precipitated resin was filtered off and dried under reduced pressure to obtain a white powder resin. The structural formula of this resin 1 is shown below.

Resin 1 had a weight average molecular weight (Mw) of 7000 and a dispersity (Mw / Mn) of 2.2. As a result of measuring carbon 13 nuclear magnetic resonance spectrum ( ¹³ C-NMR), the composition ratio of each structural unit shown in the following structural formula was m: n: l = 0.4: 0.4: 0.2 (molar ratio). It was.

[0116] [Chemical 27]

[0117] [Example 1] Preparation and evaluation of positive resist composition

A positive resist composition was prepared by mixing the resin 1 synthesized in Synthesis Example 2, the acid generators 1 and 2 shown below, a nitrogen-containing organic compound, and a solvent.

Resin 1: 100 parts by mass,

Acid generator 1: 6.0 parts by mass,

Acid generator 2: 1.6 parts by mass,

Triethanolamine as a nitrogen-containing organic compound: 0.38 parts by mass,

PGMEA: EL = 8: 2 (mass ratio) mixed solvent as organic solvent: 750 parts by mass.

[0118] The acid generator 1 is a compound represented by the chemical formula (bl—08), and the acid generator 2 is (4 Methylphenyl) diphenylsulfonium trifluoromethanesulfonate.

“PGMEA” represents propylene glycol monomethyl ether acetate. “EL” represents ethyl lactate.

[0119] A resist pattern was formed using the positive resist composition obtained above.

That is, first, apply an organic antireflection coating composition “ARC_ 29 A” (trade name, manufactured by Plue Science Co., Ltd.) on an 8-inch silicon wafer using a spinner, and 215 ° C on a hot plate. An organic antireflection film having a thickness of 90 nm was formed by baking for 90 seconds and drying.

Next, the positive resist composition obtained above was applied onto an antireflection film using a spinner, pre-beta (PAB) at 105 ° C. for 90 seconds on a hot plate, and dried to obtain a film thickness of 180 nm. The resist film was formed.

Subsequently, an ArF excimer laser (193 nm) was applied to the resist film using an ArF exposure system NSR-S306C (Nikon Corp .; NA (numerical aperture) = 0.78, 2/3 ring zone) and 6% half-tone reticle. Then, selective exposure was performed through selective irradiation.

Thereafter, 105 ° C, a PEB treatment was conducted under conditions of 90 seconds, further 23 ° C at 2.38 mass ^_0/0 tetramethylammonium Niu arm hydroxide (TMAH) 60 seconds and puddle developed with an aqueous solution, then 20 seconds It was washed with water and shaken and dried. Further, it was heated at 100 ° C. for 60 seconds and dried to form a 1: 1 90 nm line and space pattern (hereinafter referred to as L / S pattern).

Eop is the exposure (sensitivity) when a 90nm LZS pattern is formed 1: 1.

[0120] Evaluation of the positive resist composition was performed as follows. The results are shown in Table 1 below.

<DOF>

In Eop, the focus was shifted up and down as appropriate, and the range of depth of focus (D0F) in which the 90 nm L / S pattern was obtained within the range of dimensional change rate of ± 10% was determined in nm.

[0121] <LER>

For the 90 nmL / S pattern (1: 1) obtained at Eop, 3 σ, which is a measure of LER, was determined as an evaluation of line edge roughness (LER) where the surface of the side wall of the line pattern becomes non-uniform. 3 σ was calculated from the result of measuring the width of the resist pattern of the sample at 32 locations using a side SEM (measuring SEM) (trade name “S_ 9 220” manufactured by Hitachi, Ltd.). The standard deviation is 3 times the standard deviation (3σ). This 3σ means that the smaller the value, the smaller the roughness and the uniform width resist pattern was obtained. Measurement was performed at two measurement voltages of 800V and 300V.

[0122] <Exposure margin>

It was obtained from the exposure dose (sensitivity) (Eop) for resolving 90nmL / S pattern accurately at 1: 1 and the exposure dose fluctuation range (sensitivity fluctuation range) for resolving 90% soil 10% LZS pattern. The exposure margin was calculated from the following formula.

Exposure margin (%) = [E (81nm) —E (99nm)] X 100 / Eop

In the formula, E (99 nm) is the sensitivity when obtaining a 99 nm L / S pattern (mj / cm ² ), and E (81 nm) is the sensitivity when obtaining an L / S pattern of 81 nm (mj / cm ² ).

[0123] <Pattern collapse>

When the exposure time in selective exposure was increased and the pattern width gradually narrowed along with it, we observed by SEM (scanning electron microscope) at which point the pattern collapsed.

[0124] [Comparative Example 1]

In Example 1, 3.5 parts by mass of triphenylsulfoumonium fluorobutanesulfonate (TPS-PFBS) was used in place of the acid generators 1 and 2, and the blending amount of triethanolamine was 0.35. A positive resist composition was prepared in the same manner as in Example 1 except for changing to parts by mass, and a resist pattern was formed using the resist composition.

The 90nm LZS pattern was resolved. The exposure (sensitivity) when a 90 nm LZS pattern was formed 1: 1 was defined as Eop, and the characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 1 below.

[0125] [Table 1]

As can be seen from these results, both Example 1 and Comparative Example 1 have better resolution, and LER is slightly better in Example 1. Regarding D0F, Example 1 is greatly improved compared to Comparative Example 1. In addition, even in the case of exposure margin and pattern collapse, Example 1 is superior.

Claims

Claims [1] A positive resist composition comprising a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) that generates an acid upon exposure, The component A) is a structural unit represented by the following general formula (a 1-01) and a structural unit represented by the following general formula (a 1-02)

[Chemical 1]

(a 1 -0 1) (a 1 -0 2)

[In the above formula, Y represents an aliphatic cyclic group; n represents 0 or an integer of 1 to 3; m represents 0 or 1; and R independently represents a hydrogen atom, carbon number:! To 5 A lower alkyl group, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms; and R ² each independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. At least one structural unit (al) selected from the group consisting of

The component (B) is represented by the following general formula (b-1)

[Chemical 2]

Replacement paper (Rule 26)

[Wherein, R represents an aralkyl group, an alkoxy group, a halogen atom, or a hydroxyl group, R 1 and R ¹³ each independently represents an optionally substituted aryl group or alkyl group, and n ′ represents 0 or an integer of 1 to 3 is represented. A positive resist composition comprising an onium salt acid generator (B1) having a cation moiety represented by the formula:

[2] The positive resist composition according to claim 1, wherein the component (A) has a structural unit (a2) derived from an acrylate ester having a latathone-containing monocyclic or polycyclic group.

[3] The component (A) is a structural unit other than the structural unit (a2) derived from an acrylate ester-containing structural unit (al) and a latatin-containing monocyclic or polycyclic group, and is aliphatic. 2. The positive resist composition according to claim 1, comprising a structural unit (a3) derived from an acrylate ester that contains a cyclic group-containing non-acid dissociable, dissolution inhibiting group and does not contain a polar group.

[4] The component (B) is further represented by the following general formula (b-2)

[Chemical 3] 4 "S03.» · (B-2)

[Wherein, R ⁴ "is a linear, branched or cyclic alkyl group or a fluorinated alkyl group; the scales ¹ " to! ^ "Are each independently an aryl group optionally having a substituent. Or an alkyl group, and at least one of “˜” represents an aryl group.] And an onion salt acid generator (B2) other than the component (B1). The positive resist composition as described in any one of -3.

[5] The positive resist composition according to any one of claims 1 to 3, which contains a nitrogen-containing organic compound (D).

[6] A step of forming a resist film on a substrate using the positive resist composition according to any one of claims 1 to 3, a step of exposing the resist film, and developing the resist film A resist pattern forming method including a step of forming a resist pattern.

[7] A positive resist composition comprising a resin component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) that generates an acid upon exposure,

The component (A) is a structural unit represented by the following general formula (al-01) and a structural unit represented by the following general formula (a 1-02)

[Chemical 4]

(a 1-0 1) (a 1-0 2)

'Replacement form (Rule 26) [In the above formula, Y represents an aliphatic cyclic group; n represents 0 or an integer of 1 to 3; m represents 0 or 1; and R independently represents a hydrogen atom or a carbon number of 1 to 5] A lower alkyl group, a fluorine atom, or a fluorinated lower alkyl group having 1 to 5 carbon atoms; each RR ² independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; Has at least one structural unit (al) selected, and

Replacement paper (MIIJ26) The component (B) is represented by the following general formula (b-3) or (b-4)

[Chemical 5]

¾

¾, ¾

[Wherein X "represents a C 2-6 alkylene group in which at least one hydrogen atom is substituted with a fluorine atom; Υ", Ζ "each independently represents at least one hydrogen atom is fluorine. A positive resist composition comprising an onion salt-based acid generator () 4) having an anion moiety represented by the following formula: an alkyl group having 1 to 10 carbon atoms substituted with an atom.

8. The positive resist composition according to claim 7, wherein the component (ii) has a structural unit (a2) derived from an acrylate ester having a latathone-containing monocyclic or polycyclic group.

[9] The component (A) is a structural unit other than the structural unit (a2) derived from the structural unit (al) and the acrylate ester-derived structural unit (a2) having a latathone-containing monocyclic or polycyclic group, 8. The positive resist composition according to claim 7, comprising a structural unit (a3) derived from an acrylate ester that contains a cyclic group-containing non-acid dissociable, dissolution inhibiting group and does not contain a polar group.

[10] The component (B) is further represented by the following general formula (b-20)

[Chemical 6] 2-S * SO; 20)

[Wherein R ⁴ '''represents a linear, branched or cyclic alkyl group or fluorinated alkyl group; 1 ^''' to 1 ^ '''each independently has a substituent. Represents an optionally selected aryl group or alkyl group, and at least one of R ¹ '"to R ³ ''' represents an aryl group.]

10. The positive resist composition according to any one of claims 7 to 9, comprising an onion salt acid generator (B5).

[11] The positive resist composition according to any one of claims 7 to 9, which contains a nitrogen-containing organic compound (D).

[12] A step of forming a resist film on a substrate using the positive resist composition according to any one of claims 7 to 9, a step of exposing the resist film, and developing the resist film A resist pattern forming method including a step of forming a resist pattern.