WO2007102425A1

WO2007102425A1 - Positive resist composition and method for forming resist pattern

Info

Publication number: WO2007102425A1
Application number: PCT/JP2007/054029
Authority: WO
Inventors: Yoshiyuki Utsumi
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-03-06
Filing date: 2007-03-02
Publication date: 2007-09-13
Also published as: JP2007240651A; JP4920271B2

Abstract

Disclosed is a positive resist composition containing a resin component (A) which contains a constitutional unit having an acid-cleavable dissolution inhibiting group and another constitutional unit (a0) represented by the general formula (a0-1) below, and an acid generator component (B) which generates an acid when exposed to light. The alkali solubility of the resin component (A) is increased by the action of an acid. [Chemical formula 1] (a0-1) [In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and n' represents an integer of 1 or 2.]

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 lithography technology, for example, a resist film having a resist material strength is formed on a substrate, and light, electron beam, or the like is passed through a mask on which a predetermined pattern is formed on the resist film. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing selective exposure with radiation and developing. Resist material that changes its properties so that the exposed part dissolves in the developer is positive, V does not dissolve the exposed part in the developer, and the resist material that changes in characteristics is negative.

In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, pattern miniaturization has been rapidly progressing due to advances in lithography technology.

As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, the power used in the past, typically ultraviolet rays such as g-line and i-line, has now begun mass production of semiconductor devices using KrF excimer laser and ArF excimer laser. In addition, these excimer lasers have shorter wavelength excimer lasers, electron beams, EUV (

2

Extreme ultraviolet rays) and X-rays are also being studied.

[0003] Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies these requirements, a chemical amplification containing a base resin whose alkali solubility is changed by the action of an acid and an acid generator that generates an acid upon exposure (hereinafter sometimes referred to as “PAG”). A mold register is used.

The reaction mechanism of this chemically amplified resist is that, when exposed, PAG blended in the chemically amplified resist generates an acid, and the solubility of the base resin is changed by the acid.

For example, the base solution of a chemically amplified positive resist is an acid solution that is dissociated by acid. By introducing the releasable dissolution inhibiting group, the acid dissociable dissolution inhibiting group in the exposed portion of the base resin is dissociated, and the exposed portion becomes alkali-soluble and greatly increases the solubility in the developer. .

Generally, post-exposure beta (post exposure bake; hereinafter abbreviated as “PEB”) can be used to prevent dissociation of acid dissociable, dissolution inhibiting groups and acid diffusion within the resist. It is promoted and can provide very high sensitivity compared to conventional non-chemically amplified resists.

[0004] Until now, as a base resin for chemically amplified resists, it is highly transparent to KrF excimer laser (248 nm), and polyhydroxystyrene (PHS) and its hydroxyl groups are protected with acid dissociable, dissolution inhibiting groups.榭脂 (PHS 系榭脂) has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, chemically amplified resists that use PHS-based resin as a base resin component have drawbacks such as low resolution in a process that uses light of 193 nm, for example.

Therefore, as the base resin of the resist currently used in ArF excimer laser lithography, etc., it has excellent transparency at around 193 nm, so the structural unit derived from (meth) acrylate ester chain is the main chain. Is mainly used (see, for example, Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2003-241385

Disclosure of the invention

Problems to be solved by the invention

[0005] In addition, a method of increasing the resolution by increasing the amount of the acid generator used is also used.

However, the conventional positive resist composition has a problem that PEB sensitivity decreases when the amount of the acid generator used is increased in order to obtain the necessary resolution.

Here, in this specification, “PEB Sensitivity” (hereinafter sometimes referred to as “PEBS”) means the magnitude of variation in the pattern size accompanying the change in PEB temperature (PEB temperature). The The better PEBS, the smaller the pattern size change with PEB temperature change.

Therefore, if the PEBS power is deteriorated, a desired resist pattern size cannot be stably formed when forming a resist pattern, and it becomes difficult to reproduce a pattern with fine dimensions.

This invention is made | formed in view of the said situation, Comprising: It aims at providing the positive resist composition excellent in PEBS and resolution, and a resist pattern formation method. Means for solving the problem

[0006] The present inventors propose the following means in order to solve the above problems.

That is, the first aspect (aspect) of the present invention includes a structural unit having an acid dissociable, dissolution inhibiting group and a structural unit (aO) represented by the following general formula (aO-1), A positive resist composition comprising a resin component (A) whose alkali solubility is increased by action and an acid generator component (B) which generates an acid upon exposure.

In the following general formula (aO-1), the number given around the aromatic ring phtyl group) is a position number representing the bonding position.

[0007] [Chemical 1]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; n ′ represents an integer of 1 or 2. ]

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, 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 The

In the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting the resin component (polymer).

“Exposure” is a concept that includes radiation exposure in general.

The invention's effect

[0010] According to the present invention, it is possible to provide a positive resist composition excellent in PEB sensitivity and resolution and a resist pattern forming method.

Brief Description of Drawings

FIG. 1 is a diagram showing the results of the example (a graph showing the relationship between the PEB temperature and the calculated pattern size (Calc. CD)).

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] << Positive resist yarn and composition >>

The positive resist composition of the present invention comprises a structural unit having an acid dissociable, dissolution inhibiting group and a structural unit (aO) represented by the above general formula (aO-1), and can be alkalinized by the action of an acid. A resin component (A) (hereinafter referred to as component (A)) that increases solubility and an acid generator component (B) that generates acid upon exposure (hereinafter referred to as component (B)). .

In the positive resist composition of the present invention, the component (A) is insoluble in alkali before exposure, and when an acid generated from the component (B) acts upon exposure, the acid dissociable, dissolution inhibiting group is dissociated. As a result, the alkali solubility of the entire component (A) is increased and the alkali-insoluble is changed to alkali-soluble. Therefore, in the formation of a resist pattern, when selective exposure is performed on a resist film obtained using a positive resist composition, the exposed portion turns to alkali-soluble while the unexposed portion remains alkali-insoluble. Since it does not change, alkali development can be performed.

[0013] <Component (A)>

In the present invention, the component (A) includes a structural unit having an acid dissociable, dissolution inhibiting group and a structural unit (aO) represented by the above general formula (aO-1).

The component (A) preferably further contains a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group. [0014] The acid dissociable, dissolution inhibiting group in component (A) has an alkali dissolution inhibiting property that makes the entire component (A) insoluble in alkali before dissociation, and the entire component (A) is soluble in alkali after dissociation. As long as it is changed to the above, those proposed so far as the acid-releasing dissolution inhibiting group of the base resin for chemically amplified resists can be used.

Among the components (A) containing a structural unit having such an acid dissociable, dissolution inhibiting group, a suitable resin is, for example, a structural unit derived from an acrylate ester containing such an acid dissociable, dissolution inhibiting group (al ) And so on.

[0015] Here, in the present specification and claims, the "structural unit derived from an acrylate ester force" means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester. .

In “acrylic acid ester”, a hydrogen atom is bonded to the carbon atom at position a, and in addition to the acrylic acid ester, a substituent (an atom or group other than a hydrogen atom) is bonded to the carbon atom at position a. The concept includes things. Examples of the substituent include a halogen atom, a lower alkyl group, and a no, logene-lower alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.

Note that the α position (the carbon atom at the position) of the structural unit from which the acrylate force is also derived is a carbon atom to which a carbo group is bonded, unless otherwise specified.

Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.

A “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.

A “halogenated lower alkyl group” is a halogenated alkyl group having 1 to 5 carbon atoms.

In the acrylate ester, as the lower alkyl group as the substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, η-butyl group, isopropyl group, tert-butyl group, pentyl group And a lower linear or branched alkyl group such as an isopentyl group and a neopentyl group.

In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, A hydrogen atom or a methyl group is particularly preferred from the viewpoint of industrial availability, more preferably a hydrogen atom, a fluorine atom, a lower alkyl group or a fluorinated lower alkyl group.

[0016] · Structural unit (al)

The structural unit (al) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.

As the acid dissociable, dissolution inhibiting group in the structural unit (al), those proposed so far as the acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resist can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid, etc .; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. The

The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the a-position.

Here, the “tertiary alkyl ester” is an ester formed by substitution with a hydrogen atom of a carboxy group, a chain or cyclic alkyl group, and the carboxy group ( A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of 1 C (O) —0—). In this tertiary alkyl ester, when an acid acts, the bond is broken between the oxygen atom and the tertiary carbon atom.

The chain or cyclic alkyl group may have a substituent! /. Hereinafter, a group that becomes acid dissociable by constituting a carboxy group and a tertiary alkyl ester will be referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience. Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include aliphatic branched acid dissociable, dissolution inhibiting groups, and acid dissociable, dissolution inhibiting groups containing aliphatic cyclic groups.

[0018] Here, "aliphatic" in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.

“Aliphatic branched” means that it has a branched structure without aromaticity. The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” consists of carbon and hydrogen-powered groups (carbon Hydrocarbon group), but is preferably a hydrocarbon group. Further, the “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.

As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferred. Specifically, a tert butyl group, a tert-amyl group, a tert-heptyl group, and the like can be given. I can get lost.

“Aliphatic cyclic group” indicates that it is not aromatic !, a monocyclic group or a polycyclic group.

The “aliphatic cyclic group” in the structural unit (al) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= 0), and the like.

Except for the substituents of the “aliphatic cyclic group”, the basic ring structure is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but may be a hydrocarbon group. Favored ,. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.

Specific examples of the aliphatic cyclic group include, for example, a lower alkyl group, a fluorine atom or a fluorinated alkyl group, which may or may not be substituted, monocycloalkane, bicycloalkane. Examples of the polycycloalkane force such as tricycloalkane and tetracycloalkane include groups in which one or more hydrogen atoms are removed. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Etc.

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, specifically, 2-methyl 2-adamantyl. Group, 2-ethyl-2-adamantyl group and the like. Or, in a structural unit represented by the following general formula (al "), an aliphatic cyclic group such as an adamantyl group such as a group bonded to an oxygen atom of a carbo-oxy group (-C (O)-0-) Group and this And a group having a branched alkylene group having a tertiary carbon atom, which is bonded to.

[0020] [Chemical 2]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group (the halogen atom, lower alkyl group or halogenated lower alkyl group represents a carbon atom at the α-position of the acrylate ester described above) A halogen atom as a substituent, the same as a lower alkyl group or a halogeni-lower alkyl group, and R ¹⁵ and R ¹⁶ are alkyl groups (both linear and branched, preferably 1 carbon atoms) ~ 5). ]

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal type acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal type acid dissociable, dissolution inhibiting group is bonded. . Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (pi).

[0022] [Chemical 3]

… (P 1)

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, and 0 or 1 is more preferable. Is also preferable.

Examples of the lower alkyl group for R ¹ ′ and R ² ′ include those similar to the lower alkyl group as a substituent for the α-position carbon atom of the acrylate ester, and a methyl group or an ethyl group is preferred. Groups are most preferred.

In the present invention, it is preferable that at least one of R ¹ ′ and R ² is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (pi) is preferably a group represented by the following general formula (pi-1).

[0024] [Chemical 4]

Wherein, R ¹ ', n, Y is R ¹ in the formula (pi)', n, it is the same as Y. ]

[0025] Examples of the lower alkyl group for Y include the same lower alkyl groups as the substituent for the carbon atom at the a-position of the acrylate ester.

As the aliphatic cyclic group for Y, many conventionally proposed ArF resists and the like can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups. Examples thereof are the same as the “aliphatic cyclic group”.

[0026] The acetal type acid dissociable, dissolution inhibiting group includes a group represented by the following general formula (p2).

[0027] [Chemical 5]

[Wherein R "and R ¹⁸ are each independently a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ is a linear, branched or cyclic alkyl group, or R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring.

[0028] In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, and is linear or branched. Most preferred is a methyl group, which is preferably a chain, but is preferably an ethyl group or a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is an S-methyl group.

R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be linear, branched or cyclic.

When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.

When R ¹⁹ is cyclic, it is preferably 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and further preferably 5 to carbon atoms: LO is most preferable. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. 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. Among them, a group in which one or more hydrogen atoms are removed from adamantane is preferable.

In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ The end may be bonded.

In this case, a cyclic group is formed by R ¹⁷ and R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. As the cyclic group, a 4- to 7-membered ring is preferable, and a 4- to 6-membered ring is more preferable. Specific examples of the cyclic group include a tetrahydrobiranyl group and a tetrahydrofuran group.

[0029] As the structural unit (al), a structural unit represented by the following general formula (al-0-1) and a structural unit force represented by the following general formula (al-0-2) are selected. It is preferable to use one or more.

[0030] [Chemical 6]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ¹ represents an acid dissociable, dissolution inhibiting group. ]

[0031] [7]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. . ]

[0032] In the general formula (al-0-1), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is a halogen atom or lower alkyl as a substituent of the α-position carbon atom of the acrylate ester. And the same as the group or halogen-lower alkyl group.

X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. Tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

[0033] In the general formula (al-0-2)! /, R is the same as R in the above formula (al-0-1).

X ² is the same as X ¹ in the formula (al-0-1).

Y ² is preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group, except that a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. The same as the explanation of the “aliphatic cyclic group” can be used. [0034] More specifically, the structural unit (al) includes structural units represented by the following general formulas (al-1) to (al-4).

[0035] [Chemical 8]

(a 1-2) (a 1-4)

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents 0 to 3 M represents 0 or 1; R is the same as the scale in the above formula (a 1— 0— 1), and R ¹ ′ and R ² ′ each independently represent a hydrogen atom or carbon A lower alkyl group of 1 to 5 is represented. ]

[0036] Preferably, at least one of the R ¹ 'and R ² ' is a hydrogen atom, more preferably a hydrogen atom. n is preferably 0 or 1.

[0037] X, is the same as the tertiary alkyl ester type acid-releasing dissolution inhibiting group exemplified for X ¹ in the above formula (al-0-1).

Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the explanation of the “aliphatic cyclic group”.

[0038] Specific examples of the structural units represented by the general formulas (al-1) to (al-4) are shown below.

[0039] [Chemical 9]

0]

ccl

(a1-1-17) (a 1-1 -18)

1]

Four]

() a () lal32--

To 〔s 〔ffi004l

(a1-3-21) (a1-3-22) (a1-3-23) (a1-3-24)

9]

(a1-4-26) (a1 -4-27) (a 1 -4-28) (a 1 -4-29) (a1-4-30)

In the component (A), as the structural unit (al), one type may be used alone, or two or more types may be used in combination.

Of these, the structural units represented by the general formula (al-1) are specifically preferred (al-1-11) to (al-1-6) or (al-1 35) to (al-1). It is more preferable to use at least one selected from the structural units represented by —41).

Furthermore, as the structural unit (al), in particular, structural units represented by the formulas (al 1 1) to (al 1-4) Represented by the following general formula (al — 1 01), and the general formula (a 1 — 1 02) including the structural units of the formulas (al — 1 35) to (al — 1 -41) Also preferred ,.

[0051] [Chemical 20]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group. ]

[Chemical 21]

[Wherein, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² represents a lower alkyl group. h represents an integer of 1 to 3. ]

In the general formula (al-1-01), R is the same as R in the above formula (al-0-1). The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R in the above formula (al-0-1), and is preferably a methyl group or an ethyl group.

In the general formula (al-1-02),! /, And R! / Are the same as R in the above formula (al-0-1). The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R in the above formula (al-0-1), and a methyl group or an ethyl group is most preferable. h is 1 or

2 is preferred 2 is most preferred.

[0055] In the component (A), the proportion of the structural unit (al) is 10% of the total structural units constituting the component (A).

More preferably preferred instrument 20 to 70 mole ^_0/0 forces 80 mole ^_0/0, further preferred 25 to 50 mole ^_0/0 That's right. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting the resist composition value to the upper limit value or less, it is possible to balance with other structural units.

[0056] · Unit (aO)

In the present invention, the component (A) further contains a structural unit (aO) represented by the general formula (aO-1). PEB Sensitivity is improved by including the structural unit (aO). The reason for this is not clear, but the main factor is that the interaction between the phenolic hydroxyl group in the structural unit (aO) and the acid generated from component (B) by exposure (such as hydrogen bonding) is significant! It is estimated that it is one of the following.

In the general formula (aO-1), R represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated lower alkyl group. The halogen atom, lower alkyl group or halogenated lower alkyl group of R is the same as the halogen atom, lower alkyl group or halogenated lower alkyl group as the substituent of the α-position carbon atom of the acrylate ester. Is mentioned. R is most preferably a methyl group.

In the general formula (aO-1), the bonding position between the terminal oxygen atom of the carbonyloxy group (one C (O) —O—) and the hydroxyl group-containing naphthyl group is easily available and low. U is preferred because it is price.

[0059] In the general formula (aO-1), n is an integer of 1 or 2, and is preferably a force 1 that is excellent in the effects of the present invention.

The substitution position of the hydroxyl group is preferably the 5-position because n ′ is 1 because it is readily available and inexpensive. Furthermore, when n is 2, any substitution position can be combined.

[0060] Specific examples of preferred structural units as structural units (aO) are shown below.

[0061] [Chemical 22]

[0062] Among the above, the structural units represented by the chemical formulas (aO-1 1) and (aO-1 12) are more preferred, and the structural unit represented by the chemical formula (aO-1 1) is most preferred. .

In the component (A), as the structural unit (aO), one type may be used alone, or two or more types may be used in combination.

Component (A), the amount of the structural unit (aO-) based on the combined total of all structural units constituting the component (A), more preferably from 1 to 50 mole ^_0/0 preferably fixture 2-30 mole ^_0/0 more preferably immediately 3-20 mole ^_0/0, most preferably 5 to 15 mol ^_0/0. PEB Sensitivity is improved by setting the value below the lower limit. On the other hand, by setting it to the upper limit value or less, it is possible to balance with other structural units and to improve lithography properties such as resolution.

[0063] · Structural unit (a2)

In the present invention, the component (A) preferably further contains a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

Here, the ratatone-containing cyclic 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 if it is only a rataton ring, it is called a monocyclic group, and if it has another ring structure, it is called a polycyclic group regardless of the structure.

When the (A) component is used to form a resist film, the Rataton cyclic group in the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective for raising.

As the structural unit (a2), any unit can be used without any particular limitation.

Specifically, examples of the latatatone-containing monocyclic group include groups in which y-peptidyl latatone force hydrogen atom is removed. In addition, as the latatatone-containing polycyclic group, a biphenyl group having a latathone ring Cycloalkane, tricycloalkane, and tetracycloalkane forces also include groups in which one hydrogen atom has been removed.

[0065] Specific examples of the structural unit (a2) include structural units represented by the following general formulas (a2-1) to (a2-5).

[0066] [Chemical 23]

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is 0. Or an integer of 1. ]

[0067] R in the general formulas (a2-l) to (a2-5) is the same as R in the structural unit (al).

The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (al).

In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

Specific examples of the structural units of the general formulas (a2-1) to (a2-5) are shown below.

[0068] [Chemical 24]

酉

I

[] [] 006952

one

Among these, it is preferable to use at least one selected from the general formulas (& 2-1-1) to (& 2-5) V, and the general formulas (a2-1) to (a2— It is more preferable to use at least one selected from 3). Specifically, the chemical formulas (a2—1—1), (a2—l—2), (a2—2—1), (a2—2—2), (a2—3—l), (a2—3) — It is particularly preferable to use at least one selected from (2), (a2-3-9) and (a2-3-10).

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

The proportion of (A) the structural unit in the component (a2) is for the total of all structural units constituting the component (A), 5 to 60 mole ^_0/0 force transducer preferred, 10 to 50 mole ^_0/0 more preferably the force, preferably 20 to 50 mole ^_0/0 force of et. 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 it to the upper limit value or less, it is possible to balance with other structural units.

[0075] · Unit (a3)

In the present invention,ヽalso it preferred to include component (A), further Atari Le acid containing a polar group-containing aliphatic hydrocarbon group Esuterukaゝet the induced structural units _(a 3). Structural unit (a3) By including, 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.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group substituted with a partial S hydrogen atom of an alkyl group, and a hydroxyl group is particularly preferred.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is possible. As the polycyclic group, for example, many resins for resist compositions for ArF excimer lasers have been proposed and can be appropriately selected and used.

Among them, it is derived from an acrylate ester group containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, cyano group, carboxy group, or alkyl group is substituted with a fluorine atom. The structural unit is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms are removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, two or more hydrogen atoms are removed from adamantane, two or more hydrogen atoms are removed from norbornane, and two or more hydrogen atoms are removed from tetracyclododecane. The industrial group is preferred.

[0076] As the structural unit (a3), 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, a hydroxyethyl ester ester of acrylic acid is used. When the hydrocarbon group is a polycyclic group, the structural unit derived from it is preferred. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1) is represented by the following formula (a3-2) A structural unit represented by the following formula (a3-3) is preferable.

[0077] [Chemical 29]

(a3-3)

[In the formulas (a3-l) to (a3-3), R is the same as R in the above formula (al-0-1), j is an integer of 1-3, k is 1-3 An integer of 1 to 3, 1 is an integer of 1 to 5, and s is an integer of 1 to 3. ]

In the formula (a3-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, a hydroxyl group is preferably bonded to the 3rd position of the adamantyl group.

j is preferably 1, and the hydroxyl group is particularly preferably bonded to the 3rd position of the adamantyl group.

[0079] In the formula (a3-2), k is preferably 1. The cyan group is preferably bonded to the 5th or 6th position of the norbornyl group.

In formula (a3-3), t ′ is preferably 1. 1 is preferably 1. s is preferably 1. In formula (a3-3), it is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. It is preferred that the fluorinated alkyl alcohol be bonded to the 5th or 6th position of the norbornyl group! /.

In the component (A), as the structural unit (a3), one type may be used alone, or two or more types may be used in combination.

Component (A), the proportion of the structural unit (a3), the (A) against the total of all structural units constituting the component 5 to 50 mol ^_0/0 it is preferably a tool 40 mol ⁰ / ₀ forces Ri preferably, more preferably 5 to 25 mol ^_0/0 power. By setting it to the lower limit value or more, the effect of improving the resolution and the like by obtaining the structural unit (a3) can be obtained, and by setting it to the upper limit value or less, it is possible to obtain a lance with other structural units. [0082] 'Unit (a4)

The component (A) may contain another structural unit (a4) other than the structural units (aO) and (al) to (a3) as long as the effects of the present invention are not impaired.

The structural unit (a4) is not classified into the structural units (aO) and (al) to (a3) described above, and is not particularly limited as long as it is another structural unit. For ArF excimer laser, KrF excimer laser A number of hitherto known materials can be used as those used for resist resins such as those for use with ArF excimer lasers (preferably for ArF excimer lasers).

As the structural unit (a4), for example, a structural unit derived from an ester acrylate ester containing an acid non-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (al), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser). A large number of conventionally known strengths can be used as the oil component of the resist composition.

In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Specifically, as the structural unit (a4), those having the structures of the following general formulas (a4-l) to (a4-5) can be shown in column f.

[0083] [Chemical 30]

[Wherein, R is the same as R in the above formula (al-0-1). ]

[0084] When the structural unit (a4) is included in the component (A), the structural unit (a4) is added in an amount of 1 to 30 mol ⁰ with respect to the total of all structural units constituting the component (A). / ₀ , preferably 10 to 20 mol% It is preferable to have it.

[0085] In the present invention, the component (A) has an acid dissociable, dissolution inhibiting group, and at least the general formula

A resin component containing the structural unit (aO) represented by (aO-1) (preferably further the structural unit (a2)).

Such component (A) may be used alone or in combination of two or more.

[0086] As the component (A), when two or more kinds are used in combination, for example, a mixture containing two kinds of polymers may be mentioned. Examples of such a mixture include a mixture containing a copolymer having the structural unit (al) and the structural unit (aO), and a polymer having the structural unit (al).

Among them, a polymer (A1) having the structural unit (al) and the structural unit (aO), a polymer having the structural unit (al) and not having the structural unit (aO) ( A mixture containing A2) is particularly preferred. By using the polymer (A1) and the polymer (A2) in combination, an effect of improving PEBS can be obtained, and the resolution of the formed resist pattern is also good. Thus, the reason why PEBS is improved and the resolution of the resist pattern is good is not clear, but the resist composition containing the polymer (A1) is particularly included in the polymer (A1). PEBS is good due to the effect of the structural unit (aO), while the resist composition containing the polymer (A2) has particularly good resolution. By using the polymer (A1) and the polymer (A2) in combination, the proportion of the structural unit (aO) in the component (A) is adjusted, the PEBS force S is improved, and the resist pattern to be formed It is estimated that the resolution of is good. Hereinafter, the polymer (A1) and the polymer (A2) will be described.

[0087] [Polymer (A1)]

In the present invention, the polymer (A1) is a copolymer having the structural unit (al) and the structural unit (aO). The polymer (A1) preferably further has the structural unit (a2).

The polymer (A1) may have other structural units other than the structural units (al), (aO), and (a2) as long as the effects of the present invention are not impaired. However, it is preferable that the structural unit (a3) does not exist.

[0088] In the polymer (A1), the proportion (molar ratio) of each structural unit improves the effect of the present invention. Therefore, the structural unit (al) is preferably 10 to 80 mol%, more preferably 20 to 70 mol% with respect to all the structural units constituting the polymer (Al). More preferably, it is 50 mol%.

The structural unit (aO-) more preferably preferably fixture 2-30 mole ^_0/0 forces 50 mole ^_0/0, more preferably 3 to 20 molar%, 5 to the most preferred 15 mole%.

The structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 20 to 50 mol%.

In addition, when the structural unit (a4) is contained in the polymer (A1), the content is preferably 1 to 30 mol%, more preferably 10 to 20 mol%.

[0089] In the present invention, the polymer (A1) is preferably exemplified by the structural unit (al),

a copolymer having (aO) and (a2). Examples of such a copolymer include the above-mentioned structural units (al), (aO) and (a2) ), (AO), (a2) and a copolymer comprising (a4).

Among these, preferred specific examples of the polymer (A1) include a polymer (Al 1) having a combination of structural units represented by the following general formula (A1-11). This polymer (Al 1) is excellent in PEBS, in which the amount of change in pattern size associated with changes in PEB temperature is small.

[0090] [Chemical 31]

(A −) In the general formula (A1-11), R is the same as R in the above formula (al-0-1). The lower alkyl group for R ^{2 is the same as} the lower alkyl group for R in the above formula (al-0-1). Most preferred is a methyl group, preferably a methyl group or an ethyl group.

The bonding position between the oxygen atom at the terminal of the carbonyloxy group (—C (O) -0-) and the hydroxyl group-containing naphthyl group is preferably the 1-position of the naphthyl group.

N ′ is the same as n ′ in the above formula (aO-1), and is preferably 1. The hydroxyl substitution position is preferably the 5-position in the naphthyl group.

[0092] The mass average molecular weight (Mw) of the polymer (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but 2,000-50,000 is preferred <, Preferable over 3,000 to 30,000 power <, 5,000 to 20,000 power ^ The most preferable! / ヽ. If it is below the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is above the lower limit of this range, the dry etching resistance and resist pattern cross-sectional shape are good.

Further, the dispersity (MwZMn) of the polymer (A1) is preferably 1.0 to 5.0 force S, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. Mn represents a number average molecular weight.

In the component (A), as the polymer (A1), one type may be used alone, or two or more types may be used in combination.

[0094] [Polymer (A2)]

In the present invention, the polymer (A2) has the structural unit (al) and does not have the structural unit (aO). The polymer (A2) preferably further has the structural unit (a2) and Z or the structural unit (a3).

The polymer (A2) has other structural units (a4) other than the structural units (al) to (a3) and (aO) as long as the effects of the present invention are not impaired! /, Anyway!

[0095] In the polymer (A2), the proportion (molar ratio) of each structural unit is the structural unit relative to all the structural units constituting the polymer (A2) because the effect of the present invention is improved. (al) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, and even more preferably 25 to 50 mol%.

The structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 20 to 50 mol%. The structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and even more preferably 5 to 25 mol%.

Further, when the structural unit (a4) is contained in the polymer (A2), the content is preferably 1 to 30 mol%, more preferably 10 to 20 mol%.

[0096] In the present invention, examples of suitable polymers (A2) include the structural unit (al),

and a copolymer having (a2) and (a3). The copolymer includes the structural unit (al), (a2) and (a3) a copolymer having a force, and the structural unit (al ), (A2), (a3) and (a4).

Among these, preferred specific examples of the polymer (A2) include a polymer (A21) having a combination of structural units represented by the following general formula (A2-11). This polymer (A21) is particularly excellent in the resolution of the resist pattern to be formed.

[0097] [Chemical 32]

(A 2-1 1)

In the general formula (A2-11),! /, And R! / Are the same as R in the above formula (aO-1). R ² is the same as described above, and most preferably a methyl group.

[0099] The mass average molecular weight (Mw) of the polymer (A2) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but 2,000-50,000 is preferred <, Preferable over 3,000 to 30,000 power <, 5,000 to 20,000 power ^ The most preferable! / ヽ. If it is below the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is above the lower limit of this range, the dry etching resistance and resist pattern cross-sectional shape are good.

Further, the dispersity (MwZMn) of the polymer (A2) is preferably 1.0 to 5.0, and preferably 1.0 to 3.0. More preferred 1. 2 to 2.5 is most preferred.

[0100] When the component (A) contains the polymer (A1) and the polymer (A2), such a polymer (

The mixing ratio of A1) to polymer (A2) is preferably 1: 9 to 9: 1 by mass ratio.

It is more preferable that it is ˜8: 2. Most preferably, it is 2: 8 to 6: 4. By setting it within the above range, the effect of the present invention is excellent.

In the present invention, as the component (A), in particular, the polymer (Al 1) represented by the general formula (A1-11) and the polymer (A21) represented by the general formula (A2-11) Those containing the combination are most preferably used.

[0101] The component (A) is a monomer derived from each structural unit, for example, azobisisobutyl-tolyl

It can be obtained by polymerizing by a known radical polymerization using a radical polymerization initiator such as (AIBN).

In addition, the component (A) includes, for example, HS—CH—CH—CH—C (CF

2 2 2

) — When used in combination with a chain transfer agent such as OH, the terminal C 1 (CF) —OH

3 2 3 2 groups may be introduced. In this way, a copolymer in which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is used to reduce development defects and LER (Line Edge Roughness: uneven unevenness of the line sidewall). ).

In the case of a mixture, the component (A) can be obtained by, for example, producing each polymer by the above polymerization method and mixing these polymers.

[0102] The mass average molecular weight (Mw) of the total component (A) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but 2,000-50,000 force S is preferred. <, 3,000 to 30,000 power is preferred <, 5,000 to 20,000 power ^ most preferred! / ヽ. If it is below the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is above the lower limit of this range, the dry etching resistance and resist pattern cross-sectional shape are good. It is.

Further, the dispersity (MwZMn) of the whole component (A) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

In the positive resist composition of the present invention, the content of the component (A) should be adjusted according to the thickness of the resist film to be formed. [0103] <(B) component>

The component (B) is not particularly limited, and those that have been proposed as acid generators for chemical amplification resists can be used. Examples of such acid generators include onium salt acid generators such as ododonium salts and sulfo salt, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes. A wide variety of acid generators such as diazomethane acid generators such as poly (bissulfol) diazomethanes, nitrobenzilsulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators are known.

[0104] As the form salt-based acid generator, for example, an acid generator represented by the following general formula (b-0) can be suitably used.

[0105] [Chemical 33]

[Wherein, ¹ represents a linear, branched, or cyclic alkyl group, or a linear, branched, or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, or a halogen atom. , A linear or branched alkyl group, a linear or branched halogenated alkyl group, or a linear or branched alkoxy group; R ⁵³ may have a substituent. U, is an integer from 1 to 3. ]

In the general formula (b-0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic 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 preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and still more preferably 6 to carbon atoms: LO.

The fluorinated alkyl group is most preferably 1 to 4 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. In addition, the fluorination rate of the fluorinated alkyl group (the number of substituted fluorine atoms relative to the total number of hydrogen atoms in the alkyl group) The ratio of the number of atoms) is preferably 10 to 100%, and more preferably 50 to 100%. Particularly, all hydrogen atoms are substituted with fluorine atoms. This is preferable because the strength of the acid increases.

R ⁵¹ is most preferably a linear alkyl group or a fluorinated alkyl group.

[0108] R ⁵² is a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched halogen alkyl group, or a linear or branched alkoxy group. .

In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.

In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.

In R ⁵² , the halogenated alkyl group is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Examples of the alkyl group here are the same as the “alkyl group” in R ⁵² . Examples of the halogen atom to be substituted include the same as those described above for the “norogen atom”. In the halogenated alkyl group, it is desirable that 50 to 100% of the total number of hydrogen atoms are substituted with halogen atoms, and it is more preferable that all are substituted.

In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.

Among these, R ⁵² is preferably a hydrogen atom.

[0109] R ⁵³ is an aryl group which may have a substituent, preferably an aryl group having 6 to 20 carbon atoms. The structure of the basic ring (matrix ring) excluding the substituent includes a naphthyl group, Examples thereof include a phenyl group and an anthracenyl group, and a phenyl group is desirable from the viewpoint of the effects of the present invention and the absorption of exposure light such as an ArF excimer laser.

Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, preferably having 5 or less carbon atoms, particularly preferably a methyl group).

As the aryl group for R ⁵³ , those having no substituent are more preferable. u and 'are integers of 1 to 3, 2 or 3 is preferred, and 3 is particularly desirable.

[0110] Preferred examples of the acid generator represented by formula (b-0) include the following.

[0111] [Chemical 34]

[0112] The acid generators represented by the general formula (b-0) can be used alone or in combination of two or more.

[0113] Other examples of the sodium salt-based acid generator represented by the general formula (b-0) include compounds represented by the following general formula (b-1) or (b-2). Are also preferably used.

[0114] [Chemical 35]

l ⁺ R ⁴ "SO '" 3-(b-2)

[Wherein R ¹ "^ ³ ", R ⁵ "to R ⁶ " each independently represents an aryl group or an alkyl group; R ⁴ "represents a linear, branched or cyclic alkyl group or a fluorinated alkyl. Represents at least one of,, ~ "represents an aryl group, and at least one of R ⁵ " to R ⁶ "represents an aryl group. ]

In formula (b— 1),,, ~ "each independently represents an aryl group or an alkyl group. Of R ¹ " to R ³ ", at least one represents an aryl group! ^ ¹ " ~! ^ It is preferred that 2 or more of ³ “are aryl groups. Most preferably, all of“ ˜ ”are aryl groups. The aryl group of R ^{lw to} R ³ "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. It may not be substituted with a group, 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. For example, a phenol group and a naphthyl group can be mentioned.

Examples of the alkyl group on which the hydrogen atom of the aryl group may be substituted include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, which are preferably alkyl groups having 1 to 5 carbon atoms. That is the most preferred.

As the alkoxy group that may be substituted with a hydrogen atom of the aryl group, a methoxy group and an ethoxy group are preferred, with an alkoxy group having 1 to 5 carbon atoms being preferred.

The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

The “˜” alkyl group is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. From the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5. Specifically, a methyl 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 hexyl group, a cyclohexyl group, a nonyl group, A decanyl group and the like can be mentioned, and a methyl group can be mentioned as a preferable one because it is excellent in resolution and can be synthesized at low cost.

Among these, R ^{lw to} R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group. The linear or branched alkyl group preferably has 1 to 10 carbon atoms. Most preferably, it is 1 to 4 carbon atoms.

The cyclic alkyl group is a cyclic group as shown by the above R ¹ ″, preferably a carbon number of 4 to 15 carbon atoms, more preferably a carbon number of 4 to 10 carbon atoms. Most preferably, the number is from 6 to 10.

The fluorinated alkyl group is most preferably 1 to 4 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. In addition, The fluorination rate of the alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to: L0 0%, more preferably 50 to 100%, and in particular, all hydrogen atoms are substituted with fluorine atoms However, it is preferable because the strength of the acid is increased.

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

In formula (b-2), R ⁵ ″ and R ⁶ ″ each independently represent an aryl group or an alkyl group.

At least one of R ⁵ "and R ⁶ " represents an aryl group. It is preferred that both R ⁵ ″ and R ⁶ ″ are aryl groups.

Examples of the aryl group of R ⁵ "and R ⁶ " include those similar to the aryl groups of,, ~.

As the alkyl group for R ⁵ ″ and R ⁶ ″, the same as the alkyl groups for.

Of these, R ⁵ ″ and R ⁶ ″ are most preferably a phenol group. Those similar to - "(1 b) R ⁴ in the formula is as" the like R ⁴ of formula (b-2) in.

[0118] Specific examples of the sodium salt acid generator represented by the formulas (b-1) and (b-2) include difluoro-rhodonium trifluoromethanesulfonate or nonafluorobutanesulfonate. Bis (4-tert-butylphenol) trifluoromethanesulfonate or nonafluorobutanesulfonate, trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorolob Tansusulfonate, tri (4 methylphenol) sulfurium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfotrifluoromethane Lomethanesulfonate and its heptafluoropropanesulfonate Or its nonafluorobutane sulfonate, monophenyl dimethyl sulfone trifluoromethane sulfonate, its heptafluoropropane sulphonate or its nonafluorobutane sulfonate, diphenyl mono methinores noreform trifno leo Lomomethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of (4 methylphenol) diphenylsulfomethane, its heptafluoropropanesulfone Or its nonafluorobutane sulfonate, (4-methoxyphenol) diphenyl trifonoleolomethane sulphonate of senorephonium, its heptafluororeopropane sulphonate or its nonafluorobutane sulphonate, tri (4 tert —Butyl) phenolsulfurium trifanololomethanesulphonate, its heptafluororenopropane sulphonate or its nonafluorobutane sulphonate, diphenol (1 (4-methoxy) naphthyl) sulphononium Trifluoromethanesulfonate, its heptafluoromethane sulfonate, its heptafluororenopropane sulphonate or its nonafluorobutane sulfonate, di (1 naphthyl) phenol sulfone trifluoromethane sulfonate, its heptafluoro Propanesulfonate or so Nonafluorobutane sulfonate and the like. In addition, ohmic salts in which the ionic part of these ohmic salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

[0119] In addition, in the general formula (b-1) or (b-2), the anion part is replaced with a caron part represented by the following general formula (b-3) or (b-4). A -um salt-based acid generator can also be used (the cation moiety is the same as (b-1) or (b-2)).

[0120] [Chemical 36]

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

[0121] X "is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 3 carbon atoms. 5 and most preferably 3 carbon atoms.

Υ "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 has 1 to 10 carbon atoms, preferably It is C1-C7, More preferably, it is C1-C3.

The carbon number of the alkylene group of X "or the carbon number of the alkyl group of Υ" and Ζ " Within this range, a smaller value is preferred 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 and the higher the energy of 200 nm or less. And U is preferred because of its improved transparency to electron beams, and the proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to LOO%. Most preferably, it is a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0122] In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and generates an acid upon irradiation with radiation. It is what has. Such oxime sulfonate acid generators are widely used for chemically amplified resist compositions, and can be arbitrarily selected and used.

[0123] [Chemical 37]

—— c = N 1 0- S0 ₂ 1 R ³¹

R ³² ■ ■ · (B-1)

(In the formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

[0124] The organic group of R ³¹ and R ^{32 is} a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (a fluorine atom, a chlorine atom, etc. ) Etc.).

As the organic group for R ³¹ , a linear, branched or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. The substituent is not particularly limited, and examples thereof include a fluorine atom and a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent. As the alkyl group, 1 to 20 carbon atoms are preferable. 1 to 10 carbon atoms are more preferable. 1 to 8 carbon atoms are more preferable. 1 to 6 carbon atoms are particularly preferable. 1-4 carbon atoms are particularly preferable. Most preferred. Alkyl groups include in particular partially or fully halogenated alkyl groups (hereinafter And sometimes referred to as a halogenated alkyl group). The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the completely halogenated alkyl group means that all the hydrogen atoms are halogen atoms. It means an alkyl group substituted by. Examples of the halogen atom include a fluorine atom, a chlorine atom, an fluorine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group! /.

The aryl group is preferably 4 to 20 carbon atoms, preferably 4 to 20 carbon atoms, and most preferably 6 to 10 carbon atoms, more preferably L0. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. A partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and a completely halogenated aryl group means that all hydrogen atoms are halogenated. An aryl group substituted with an atom.

R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ³² , a linear, branched, or cyclic alkyl group, aryl group, or cyan group is preferable. Examples of the alkyl group and aryl group for R ³² include the same alkyl groups and aryl groups as those described above for R ³¹ .

R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

[0126] More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

[0127] [Chemical 38]

R ³⁴ — C = N― O― S0 ₂ "~ R ³⁵

R ³³ … (B-2)

[In the formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenalkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

[0128] [Chemical 39]

[In the formula (B-3), R ^db represents a cyano group, an alkyl group having no substituent, or a halogen alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. R ³⁸ is an alkyl group having no substituent or a halogenated alkyl group. p ', is 2 or 3. ]

[0129] Te you, the general formula (B- 2), Do no substituent of R ^33, an alkyl group or a halogenated alkyl group, 1 to carbon atoms: preferably be a L0 device carbon Numbers 1-8 are more preferred Carbon numbers 1-6 are most preferred.

R ³³ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

The fluorinated alkyl group in R ³³ is preferably fluorinated with 50% or more of the hydrogen atom of the alkyl group, more preferably 70% or more, and even more preferably 90% or more. I like it! /

[0130] The aryl group of R ³⁴ includes an aromatic hydrocarbon such as a phenol group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, a phenanthryl group, and the like. Ring force A group in which one hydrogen atom is removed, and a heteroaryl group in which a part of the carbon atoms constituting the ring of these groups are substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Can be mentioned. Among these, a fluorenyl group is preferable.

The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 4 carbon atoms, more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

[0131] The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. Most preferred.

R ³⁵ is most preferably a partially or fully fluorinated alkyl group, preferably a halogenated alkyl group! / !.

The fluorinated alkyl group in R ³⁵ is such that 50% or more of the hydrogen atoms in the alkyl group are fluorinated. More preferably, it is fluorinated by 70% or more, more preferably 90% or more, since the strength of the acid generated increases. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

[0132] In the general formula (B-3), the alkyl group or the halogenated alkyl group having no substituent of R ³⁶ is an alkyl group or a group having no substituent of R ³³ described above. Examples thereof are the same as the halogenalkyl group.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups in which the aryl group strength of R ³⁴ is one or two hydrogen atoms removed.

Do no substituent of R ^38, the alkyl group or Harogeni spoon alkyl group, the same alkyl group or Harogeni spoon alkyl group containing no substituent group of the ⁵ like et be.

P ′ ′ is preferably 2.

[0133] Specific examples of oxime sulfonate-based acid generators include α- (p-toluenesulfo-oxyximino) monobenzyl cyanide, α- (ρ chlorobenzene-sulfo-oxyoximino) -benzyl cyanide, α- ( 4-Nitrobenzenesulfo-luoxyimino) -Benzyl cyanide, Hiichi (4-troo 2 trifluoromethylbenzenesulfo-ruximino) Benzyl cyanide, α- (Benzenesulfo-ruximino) —4-Clorobenzoylcia-do , Α (Benzenesulfo-ruximino) — 2, 4 dichlorobenzil cyanide, α — (Benzenesulfo-ruximino) — 2, 6 dichlorobenzil cyanide, α (Benzenesulfo-ruximino) 4-methoxybenzyl cyanide , Α-(2-Clorobenzobenzene-Luximinomino) -4-methoxybenzyl cyanide, α-(Benzene Sulfone-ruximino) —Chen—2-ylacetonitrile, at- (4-dodecylbenzenesulfo-ruximino) —benzyl cyanide, α-[(ρ Toluenesulfo-roximino) -4-methoxyphenyl] acetonitrile, α [(Dodecylbenzenesulfo-luoxyimino) -4-methoxyphenyl] acetonitrile, at- (tosyloximino) -4-cercia-do, α (methylsulfo-luximino)-1-cyclopente-rucetonitrile, α- (Methylsulfo-Luoxyimino) — 1-Cyclohexyl-Luacetonitrile, OC-(Methylsulfo-Luoxyimino) 1-Cycloheptulucetonitrile, α (Methylsulfo -Luoxyimino) — 1-Cyclooctaturacetonitrile, α- (Trifluoromethylsulfo-luoximino) — 1-Cyclopente-Lucetonitrile, _α- (Trifluoromethylsulfo-Luoxyimino) -Cyclohexylacetonitrile , alpha (Echirusuruho - Ruoki Shiimino) - E chill § Seto nitrile, OC - (propylsulfonyl - Ruokishiimino) - Puropirua Seto - tolyl, _alpha - (Kishirusuruho cyclohexylene - Ruokishiimino) - cyclopentyl Rua Seto nitrile, a - (Kishirusuruho cyclohexane -Luoxyimino) —Cyclohexylacetonitrile, a- (Cyclohexylsulfo-Luoxyimino) — 1-Cyclopente-Lucetonitrile, a- (Ethylsulfo-Luoxyimino) — 1-Cyclopente-Luacetonitrile, α (Isopropylsulfo-Luoximino) ) — 1-Cyclopentylacetonitrile, a-(η-Butylsulfonyloxyimino) 1-Cyclopentenylacetonitrile, α (Ethylsulfo-ruximino) — 1-Cyclohexyl-acetonitrile, α- (Isopropylsulfuroxymino) 1-Cyclohexyl-acetonitrile, （( _η -butylsulfo-methoxy) 1-Cyclohexyl-acetonitrile, α (Methylsulfo-hydroxyimino) -phenolacetonitrile, OC-(Methylsulfo-methoxy) -ρ-methoxyphenylacetonitrile, α -(Trifluoromethylsulfo-ruximino) -phenylaceto-tolyl, _α- (Trifluoromethylsulfo-ruximino) -p-methoxyphenylacetonitrile, at- (Ethylsulfonyloxyimino) -p —Methoxyphenol Asetonito Lil, alpha-(propylsulfonyl - Ruokishiimino) p Mechirufue - Ruasetonitoriru, alpha (Mechirusuruho - Ruokishiimino) [rho Buromofue - Ruasetonitoriru like are Ru mentioned.

Also disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chemical Formula 18] to [Chemical Formula 19]) !, Ruoxime sulfonate acid generator, WO2004Z074242A2 (65 to 85) The oxime sulfonate acid generators disclosed in Examples 1 to 40) on the page can also be suitably used.

Moreover, the following can be illustrated as a suitable thing.

[Chemical 40] ]

o, I, —— 1 i

[0136] Of the above exemplified compounds, the following four compounds are preferred.

[0137] [Chemical 42]

[0138] Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfol diazomethanes include bis (isopropylsulfol) diazomethane, bis (p toluenesulfol) diazomethane, bis (1 , 1-dimethylethylsulfol) diazomethane, bis (cyclohexylsulfol) diazomethane, bis (2,4 dimethylphenylsulfol) diazomethane, and the like.

Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552 and JP-A-11-035573 can also be suitably used. Examples of poly (bissulfol) diazomethanes include 1,3 bis (phenylsulfol diazomethylsulfol) pronone, 1, 4 disclosed in JP-A-11 322707. Bis (phenylsulfodiazomethylsulfol) butane, 1,6-bis (phenolsulfodiazomethylsulfol) hexane, 1,10-bis (phenolsulfoldiol) Zomethylsulfo) decane, 1,2-bis (cyclohexylsulfodiazomethylsulfo) ethane, 1,3 bis (cyclohexylsulfodiazomethylsulfo) propane, 1,6 bis (cyclohexylsulfo-) (Luazomethylsulfol) hexane, 1,10-bis (cyclohexylsulfoldiazomethylsulfol) decane, and the like.

[0139] As the component (B), one type of these acid generators may be used alone, or two or more types may be used in combination.

In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an ion as the component (B).

The content of the component (B) in the positive resist composition of the present invention is 0.5 to 30 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the component (A). Within the above range Thus, pattern formation is sufficiently performed. Further, it is preferable because a uniform solution can be obtained and storage stability is improved.

<(D) component>

The positive resist composition further contains optional components to improve the resist pattern shape, post expo sure stability of the latent image formed by tne pattern-wise exposure of the resist 1 ayer, etc. It is preferable to incorporate a nitrogen-containing organic compound (D) (hereinafter referred to as component (D)).

Since a wide variety of components (D) have already been proposed, aliphatic amines, particularly secondary aliphatic amines, especially tertiary aliphatic amines, can be used arbitrarily from known ones. Is preferred.

Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity. The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity. Aliphatic amines contain at least one hydrogen atom of ammonia NH and have 12 or more carbon atoms.

Three

Examples include amines substituted with alkyl groups or hydroxyalkyl groups below (alkylamines or alkylalcoholamines) or cyclic amines.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-xylamine, n-ptylamine, n-octylamine, n-norlamin, n-decylamine; jetylamine, di-n-propylamine, di-n Dialkylamines such as ptylamine, di-n-octylamine, dicyclohexylamine; —Trialkylamines such as otatylamamine, tri-n-noramine, tri-n-de-ramine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine Emissions, di one n- O click pentanol § Min, alkyl alcohols § Min and triethylene one n- Okutanoru Amin like. Of these, tri-n-pentylamine, which is more preferable for trialkylamine having 5 10 carbon atoms, is most preferable.

Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a hetero atom. Can be mentioned. The heterocyclic compound may be monocyclic (aliphatic monocyclic ammine) or polycyclic (aliphatic polycyclic ammine).

Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. Aliphatic polycyclic amines having 6 to 10 carbon atoms are preferred, such as 1, 5 — diazabicyclo [4. 3. 0] — 5-nonene, 1, 8 — diazabicyclo [5 4. 0] — 7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane.

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).

The positive resist composition of the present invention includes, as optional components, organic carboxylic acids and phosphorus oxoacids and the like for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, and the like. Derivative power Group power At least one compound selected (hereinafter referred to as component (E)) can be contained.

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

Examples of phosphorus oxoacids and derivatives thereof include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferred.

Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atom of the oxoacid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and a carbon number of 6 ˜15 aryl groups and the like.

Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.

Examples of the phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid diol n-butenoresestenole, phenolinophosphonic acid, phosphonic acid diphenolinoestenole, and phosphonic acid dibenzyl ester.

Derivatives of phosphinic acid include phosphinic acid esters such as phenol phosphinic acid Is mentioned.

Among the above components (E), organic carboxylic acids are preferred, and salicylic acid is particularly preferred. As the component (E), one type may be used alone, or two or more types may be used in combination.

Component (E) is used in a proportion of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0142] In the positive resist composition of the present invention, there are further additives that are miscible as desired, for example, an additional grease for improving the performance of the resist film, and a surfactant for improving the coating property. Further, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

[0143] The positive resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as component (S)).

As the component (S), it is sufficient if each component to be used can be dissolved into a uniform solution. Any one of conventionally known solvents for chemically amplified resists can be used. Two or more kinds can be appropriately selected and used.

For example, latones such as γ-butyral rataton (GBL); ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-η-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, Polyhydric alcohols such as propylene glycol and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, polyethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; the polyhydric alcohols or Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether and the like, and ethers such as monophenyl ether of the compound having an ester bond [In these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethyl propionate; Tale Ginole Metinoreetenore, Difueninoreete Nore, Dipenzinoreete Nore, Feneto Inore, Butchi Examples thereof include aromatic organic solvents such as rufenyl ether, ethylbenzene, jetylbenzene, amylbenzene, isopropylbenzene, toluene, xylene, cymene and mesitylene.

These organic solvents can be used alone or as a mixed solvent of two or more. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), EL, and y-butyrolatone (GBL) are preferable. A mixed solvent in which PGMEA and a polar solvent are mixed 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: 8 to 8: 2. Preferably within range! /.

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. When PGM E is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: Three.

In addition, as the component (S), a mixed solvent of at least one selected from among PGMEA and EL and γ-petit-mouth rataton is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

Furthermore, as the component (S), the above-mentioned mixed solvent of PGMEA and PGME and the mixed solvent of γ-butyrolattone are also preferred.

The amount of component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate, etc., and can be appropriately set according to the coating film thickness.

It is used so as to be in the range of 20% by mass, preferably 5 to 15% by mass.

[0144] <Method for forming resist pattern>

Next, the resist pattern forming method of the second aspect of the present invention will be described.

The resist pattern forming method 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 developing the resist film. And a step of forming a resist pattern.

[0145] The resist pattern forming method of the present invention can be performed, for example, as follows. That is, first, the above positive resist composition is applied onto a substrate such as silicon wafer with a spinner or the like, and a pre-beta (post-apply bake (PAB)) of 40 to 40 ° C. under a temperature condition of 80 to 150 ° C. This is performed for 120 seconds, preferably 60 to 90 seconds, and ArF excimer laser light is selectively exposed through a desired mask pattern using, for example, an ArF exposure apparatus, and then subjected to a temperature condition of 80 to 150 ° C. Apply PEB (post-exposure heating) for 40 to 120 seconds, preferably 60 to 90 seconds. Next, this is developed with an alkali developer such as an aqueous solution of 0.1 to 10% by weight of tetramethylammonium hydroxide. In this way, a resist pattern faithful to the mask pattern can be obtained.

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

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

2

(Child beam), X-rays, soft X-rays and other radiation. The positive resist yarn composition according to the present invention is particularly effective for an ArF excimer laser.

Example

Next, the power to explain the present invention in more detail by way of examples The present invention is not limited by these examples.

[0147] <Synthesis example>

Examples of Synthesis of Components (A) Polymers (A1) -1 to (A2) -1 Used in Examples and Comparative Examples are shown below.

The weight average molecular weight (Mw) and dispersity (MwZMn) of each polymer are also shown.

The mass average molecular weight (Mw) and dispersity (MwZMn) were determined on a polystyrene conversion basis by gel permeation chromatography (GPC).

The composition ratio was calculated by carbon NMR. In the chemical formula, the number attached to the lower right of the structural unit indicates the ratio (mol%) of each structural unit in the polymer.

[0148] [Synthesis of Polymer (Al) —1]

In a flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer, 85 g of PGMEA was placed under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C. while stirring. a-methacryloyloxy gamma butyrolatathone 32.8 g, 2-methyl-2-adamantyl methacrylate 45. lg, 5 hydroxy 1-naphthyl methacrylate 22. Og, PGMEA 154 g, and 2,2-azobisisobuty-tolyl (AIBN) 2. The monomer solution mixed with 7 g was dropped into the flask at a constant rate over 6 hours using a dropping device, and then kept at 80 ° C for 1 hour. Thereafter, the reaction solution was returned to room temperature.

The resulting reaction solution was then added dropwise to about 30 times the amount of methanol with stirring to give a colorless precipitate. The resulting precipitate was filtered off and washed in about 30 times the amount of methanol used for the monomers used in the polymerization. The precipitate was filtered off and dried under reduced pressure at 50 ° C. for about 40 hours to synthesize polymer (A1) -1 represented by the following chemical formula.

[0149] [Chemical 43]

(A 1) One 1

(Mw: 10,000, Mw / Mn: 2.0)

[0150] [Synthesis of polymer (A2) — 1]

A flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer was charged with 85 g of PGMEA under a nitrogen atmosphere, and the temperature of the hot water bath was raised to 80 ° C. while stirring.

a-methacryloyloxy γ-butyrolatatin 32.5 g, 2-methyl-2-adamantyl methacrylate 44.8 g, 3-hydroxy-1-adamantyl methacrylate 26.6 g, PG MEA 154 g, and 2,2-azobisisobuti- A monomer solution mixed with 2.7 g of tolyl (AIBN) was dropped into the flask at a constant rate over 6 hours using a dropping device, and then kept at 80 ° C. for 1 hour. Thereafter, the reaction solution was returned to room temperature.

Next, the obtained reaction solution is added dropwise to about 30 times volume of methanol with stirring, and A colored precipitate was obtained. The resulting precipitate was filtered off and washed in about 30 times the amount of methanol used for the monomers used in the polymerization. The precipitate was filtered off and dried under reduced pressure at 50 ° C. for about 40 hours to synthesize polymer (A2) -1 represented by the following chemical formula.

[0151] [Chemical 44]

(A 2) 1

(Mw: 10,000 Mw / Mn: 2.0)

[0152] <Preparation of positive resist composition solution> (Example 12, Comparative Example 1)

Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition solution.

[0153] [Table 1]

[0154] Each abbreviation in Table 1 has the following meaning. The numerical value in [] is the blending amount (part by mass).

(B) —1: Di (1-naphthyl) phenolsulfo-munonafluorobutanesulfonate.

(D) —1: Tri-n-pentylamine.

(E) — 1: Salicylic acid.

(S) —l: γ—petit rataton.

(S) — 2: Mixed solvent with PGMEA / PGME = 6/4 (mass ratio).

[0155] <Evaluation of PEB Sensitivity> Using the obtained positive resist composition solution, PEB Sensitivity was evaluated by the following procedure.

[0156] PEB temperature conditions in the evaluation of PEB Sensitivity were 107 ° C, 110 ° C, 113 ° C.

An organic antireflection coating composition “ARC-29” (trade name, manufactured by Bruichi Science Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner, and 205 ° C, 60 ° C. on a hot plate. By baking for 2 seconds and drying, an organic antireflection film having a film thickness of 77 nm was formed. Then, the positive resist composition solution obtained above was applied onto the antireflection film using a spinner, and pre-beta (PAB) was applied on the hot plate at the PAB temperature shown in Table 3 for 60 seconds. ) Processing and drying to form a resist film with a thickness of 150 nm. Next, using ArF exposure equipment NSR-S302 (Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) ArF excimer laser (193 nm) was selectively irradiated through the mask pattern. At this time, the exposure dose was selected from nine exposure dose ranges below.

Example 1:. Exposure from 38.6 to 45 range 8MjZcm ^2.

Example 2: Exposure amount 31.4 to 38.6 mjZcm ² range.

Comparative Example 1: Exposure amount 57.0 to 66. OmjZcm ² range.

Then, in PEB temperature 107 ° C, subjected to post exposure bake (PEB) treatment was for 60 seconds, and et to at 23 ° C 2. 38 mass ^_0/0 tetramethylammonium - in Umuhidorokishido (TMAH) aqueous solution The resist pattern (line and space pattern; hereinafter referred to as L / S pattern) was formed by developing under conditions of 30 seconds, rinsing with pure water for 30 seconds, and then shaking off and drying. .

Optimal exposure amount 120nm line and space pattern (pitch 240 nm) is formed (EOP) is Example 1 42. 2 mJ / cm ^2, Example 2 30. 2 mJ / cm ^2, Comparative Example 1 is 61.5 mj, cm Shiatsu 7

[0157] (Calculation of pattern size (Calc. CD))

Measure the pattern size (actual value CD) of the L / S pattern formed above, A graph was created with the horizontal axis representing the exposure (mj / cm ² ) and the vertical axis representing the pattern size (actual value CD) (nm). From this graph, a calibration curve (relational expression) showing the relationship between the exposure dose and the pattern size (actual value CD) is obtained, and the pattern size (calculated pattern size: Calc. CD) at the EOP on this calibration curve is calculated. Asked. The results are shown in Table 2.

[0158] (PEB temperature 110 ° C pattern size (Calc. CD) calculation)

In the resist pattern formation at the PEB temperature of 107 ° C, the PEB temperature is 110 ° C, the exposure amount is 31.4 to 38.6 mjZcm ² (Example 1), the exposure amount is 26.6 to 33.8 m] / The pattern size of the calculated values is the same as in the case of the PEB temperature 107 ° C except that the range is cm ^z (Example 2) and the exposure amount is 45.0 to 54. OmjZcm ² (Comparative Example 1). (Calc. CD) was obtained. The results are shown in Table 2.

The optimal exposure (EOP) for forming a 120 nm line and space pattern (pitch 240 nm) is 35. Omj / cm ^{2 in} Example 1 and 30.

Comparative Example 1 The force was 5 mj / cm ² .

[0159] (Calculation of pattern size (Calc. CD) at PEB temperature 113 ° C)

In the resist pattern formation at the PEB temperature of 107 ° C, the PEB temperature is 113 ° C, the exposure amount is 26.6 to 33.8 mjZcm ² (Example 1), the exposure amount is 23.0 to 30.2 m] / The pattern size of the calculated value is the same as in the case of the PEB temperature of 107 ° C except that the range is cm ^z (Example 2) and the exposure amount is 37. 5-46. 5 mjZcm ² (Comparative Example 1). (Calc. CD) was obtained. The results are shown in Table 2.

The optimum exposure dose (EOP) for forming a 120 nm line and space pattern (pitch 240 nm) is 30 for Example 1.

Example 2 was 26. Comparative Example 1 The force was ² mj / cm ² .

[0160] [Table 2]

[0161] [Evaluation] From the results in Table 2, a straight line graph was created with the horizontal axis representing the PEB temperature and the vertical axis representing the calculated pattern size (Calc. CD). And the relational expression of this straight line was calculated | required. Figure 1 is a graph showing the relationship.

The slope of this relational expression is shown in Table 3 as the amount of change in pattern size per unit temperature (nmZ ° C) associated with PEB temperature change. Table 3 also shows the content (mass%) of the polymer (A1) in the component (A) and the proportion (mol%) of the structural unit (aO) in the component (A).

[Table 3]

[0163] From the results in Table 3, the change amount of the pattern size per unit temperature in Examples 1 and 2 according to the present invention is smaller than the change amount in Comparative Example 1 and is excellent in PEB Sensitivity. It could be confirmed.

Further, in Examples 1 and 2, the amount of change in pattern size per unit temperature is smaller in Example 2 where the proportion of the structural unit (aO) according to the present invention is higher than in Example 1.

It was confirmed that PEB Sensitivity was superior!

[0164] Regarding the resolution, in Examples 1 and 2, an LZS pattern having a line width of 120 nm and a pitch of 240 nm was formed, and the resolution was good.

In each example, the shape of a 120 nm line and space pattern (pitch 240 nm) formed at a PEB temperature of 110 ° C was observed with a scanning electron microscope (SEM).

It was confirmed that the resist patterns in Examples 1 and 2 were as good as those in Comparative Example 1.

From the above results, it was confirmed that Examples 1 and 2 according to the present invention were excellent in PEB Sensitivity and resolution.

Industrial applicability

[0166] The positive resist composition of the present invention was excellent in PEB Sensitivity and resolution. Therefore, when forming a resist pattern, a desired resist pattern size can be stably formed, and a pattern with fine dimensions can be reproduced. Therefore, the present invention is extremely useful industrially.

Claims

Claims A resin component comprising a structural unit having an acid dissociable, dissolution inhibiting group and a structural unit (aO) represented by the following general formula (aO-1), wherein alkali solubility is increased by the action of an acid ( A positive resist composition comprising A) and an acid generator component (B) that generates an acid upon exposure.

[Chemical 1]

[2] The ratio of the structural unit (aO) in the resin component (A) is 1 to 50 mol% with respect to all the structural units constituting the resin component (A). The positive resist composition as described.

[3] The positive resist composition according to claim 1, wherein the resin component (A) further comprises a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

[4] The polymer (A1) having the structural unit (al) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group and the structural unit (aO), as the resin component (A), Structural unit (a

2. The positive resist composition according to claim 1, comprising a polymer (A2) having 1) and not having the structural unit (aO).

[5] The positive resist composition according to claim 4, wherein one or both of the polymer (A1) and the polymer (A2) further has the structural unit (a2).

6. The positive resist composition according to claim 4, wherein the polymer (A2) further has a structural unit (a3) derived from an acrylic ester containing a polar group-containing aliphatic hydrocarbon group.

7. The positive resist composition according to claim 1, further comprising a nitrogen-containing organic compound (D).

[8] A positive resist composition according to any one of claims 1 to 7 is used on a substrate. A resist pattern forming method including a step of forming a resist film, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern.