WO2006126433A1

WO2006126433A1 - Positive resist composition and method for forming resist pattern

Info

Publication number: WO2006126433A1
Application number: PCT/JP2006/309829
Authority: WO
Inventors: Toshikazu Takayama; Shoichi Fujita; Takayoshi Mori; Koji Yonemura; Takehito Seo
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2005-05-26
Filing date: 2006-05-17
Publication date: 2006-11-30
Also published as: JP2006330401A; JP4205078B2; TW200707107A

Abstract

Disclosed is a positive resist composition containing a resin component (A) with an acid-cleavable dissolution inhibiting group whose alkali solubility is increased by the action of an acid, and an acid generator component (B) which generates an acid when exposed to light. The resin component (A) comprises a resin (A1) having a constitutional unit (a1) derived from a hydroxystyrene, a constitutional unit (a2) having an acid-cleavable dissolution inhibiting group, and a constitutional unit (a3) represented by the following general formula (a3-1). (a3-1) (In the formula, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R1 represents a hydrogen atom or an acid-cleavable dissolution inhibiting group; A represents a single bond or a divalent organic group; and Ar represents an optionally substituted arylene group.)

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.

This application claims priority based on Japanese Patent Application No. 2005-154523 filed in Japan on May 26, 2005, the contents of which are incorporated herein by reference.

Background art

In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, miniaturization has rapidly progressed due to advances in lithography technology.

As a means of miniaturization, the wavelength of exposure light is generally shortened. Specifically, the power used to use ultraviolet rays typified by g-line and i-line is now KrF. Excimer laser (248nm) has been introduced, and ArF excimer laser (193nm) has begun to be introduced. Also, shorter wavelength F excimer laser (157nm), EUV

2

(Extreme ultraviolet rays), electron beams, X-rays, etc. are also being studied.

By the way, in order to reproduce a resist pattern having a fine dimension, a resist material having high resolution is required.

As a powerful resist material, a chemically amplified resist composition containing a base resin and an acid generator that generates an acid upon exposure is used.

For example, a positive chemically amplified resist contains a resin component whose alkali solubility is increased by the action of an acid and an acid generator component that generates an acid upon exposure. When acid is generated from the generator, the exposed area becomes alkali-soluble.

As a resin component of a chemically amplified positive resist composition, a resin obtained by protecting a hydroxyl group of a polyhydroxystyrene (PHS) resin with an acid dissociable, dissolution inhibiting group is generally used.

Examples of acid dissociable, dissolution inhibiting groups include chain ether groups typified by 1-ethoxyethyl group and cyclic ether groups typified by tetrahydroviranyl group. Acid dissociable, dissolution inhibiting groups; Tertiary alkyl groups typified by tert butyl groups, tertiary alkoxy carbo yl groups typified by tert butoxycarbol groups, etc. For example, see Patent Document 1

) o

On the other hand, in the manufacture of semiconductor elements and liquid crystal display elements, an impurity diffusion layer is formed on the substrate surface.

The formation of the impurity diffusion layer is usually performed in two stages, impurity introduction and diffusion. As one of the introduction methods, impurities such as phosphorus and boron are ionized in vacuum and accelerated by a high electric field. Ion implantation (hereinafter referred to as implantation).

As a method for selectively implanting impurity ions on the substrate surface by implantation, for example, Patent Document 2 discloses a “gradient implantation” process in which implantation is performed while the substrate on which a resist pattern (mask) is formed is tilted. Has been reported. This process is considered to be an effective means when ion implantation is desired only for a small portion of the substrate that is directly under the resist pattern or the side wall of a hole formed in the substrate.

In the inclined implantation process, when a fine resist pattern of about 0.35 m is formed, the resist pattern serving as a mask has a film thickness of 0.1 to 0.5 so that ion implantation is not hindered. A thin film of about / zm is used.

Furthermore, the resist pattern in the inclined implantation process is required to have a shape characteristic for implanting ions into a desired portion of the substrate.

[0005] In a tilted implantation process (hereinafter referred to as a thin film implantation process) using a thin and strong resist pattern, particularly when a resin having high transparency to exposure light is used. In addition, the resist pattern is likely to be defective due to the influence of incident light during exposure and reflected light from the substrate. This is called a standing wave (hereinafter abbreviated as SW). In particular, when manufacturing a semiconductor element or a liquid crystal display element, a thin film implantation process is performed on a substrate on which electrodes and the like are formed. Therefore, a resist film having a uniform thickness is formed on the substrate. It is difficult. So Therefore, there is a problem of standing wave in which the resist pattern size increases or decreases with changes in the resist film thickness.

In this way, “sw” refers to a shape defect due to the influence of reflected light on a resist pattern with a constant film thickness (a phenomenon in which the side wall of the resist pattern becomes wavy), and the size of the resist pattern due to changes in the resist film thickness. Sometimes refers to a phenomenon that increases or decreases.

The change in pattern size due to SW tends to increase as the resist film becomes thinner and as the resist film becomes more transparent. Any of the above phenomena becomes a serious problem as the resist pattern becomes finer.

In order to solve such a problem, a compound (dye) having absorptivity with respect to exposure light is mixed with a resist to suppress dimensional change (for example, see Patent Document 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-341538

Patent Document 2: JP-A-8-22965

Patent Document 3: Japanese Unexamined Patent Publication No. 2003-149816

Disclosure of the invention

Problems to be solved by the invention

[0006] However, there is a limit to SW that can be reduced by blending dyes, and it is difficult to reduce SW particularly in a thin film implantation process using a thin film.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a positive resist composition and a resist pattern forming method capable of reducing the SW of a resist pattern.

Means for solving the problem

[0007] As a result of intensive studies, the present inventors have found that a functional group (SO

It was found that the above problems could be solved by using a resin having a specific structural unit having 2), and the present invention was completed.

That is, the first aspect (aspect) of the present invention is a resin component (A) that has an acid dissociable, dissolution inhibiting group and increases alkali solubility by the action of an acid, and acid generation that generates an acid upon exposure. A positive resist composition containing an agent component (B),

The rosin component (A) has a structural unit (al) that also induces hydroxystyrene power and acid dissociation. A structural unit (a2) having a soluble dissolution inhibiting group and the following general formula (a3-1)

[0008] [Chemical 1]

r— S0 ₂ — Ar— OR ¹

[Wherein R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R represents a hydrogen atom or an acid dissociable, dissolution inhibiting group; A represents a single bond or a divalent organic group; Ar represents an arylene group which may have a substituent. ]

A positive resist composition comprising a resin (A1) having a structural unit (a3) represented by: In the second aspect of the present invention, a resist film is formed on a substrate using the positive resist composition of the first aspect, and the resist film is subjected to a selective exposure treatment and then developed. This is a resist pattern forming method in which a resist pattern is formed by applying a process.

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

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

“Exposure” is a concept including general irradiation of radiation.

The invention's effect

The present invention can provide a positive resist composition and a resist pattern forming method that can reduce the standing wave of a resist pattern.

Brief Description of Drawings

FIG. 1 is a diagram showing a pattern dimension behavior with respect to a change in resist film thickness in Example 1. FIG.

[FIG. 2] FIG. 2 is a diagram showing pattern dimension behavior with respect to changes in resist film thickness in Comparative Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION [0013] << Positive resist yarn and composition >>

The positive resist composition of the present invention has a resin component (A) (hereinafter referred to as component (A)) having an acid dissociable, dissolution inhibiting group and increasing alkali solubility by the action of an acid, and exposure to light. It contains an acid generator component (B) that generates an acid (hereinafter referred to as component (B)).

In a positive positive resist composition, when an acid is generated from the component (B) by exposure, the acid dissociates the acid dissociable, dissolution inhibiting group of the component (A), thereby increasing alkali solubility. As a result, when the resist composition applied on the substrate is selectively exposed in the formation of the resist pattern, the alkali solubility in the exposed portion is increased and alkali development can be performed.

[0014] <(A) component>

For the effect of the present invention, the component (A) is composed of a structural unit (al) that also induces hydroxystyrene power, a structural unit (a2) having an acid dissociable, dissolution inhibiting group, and the above general formula (a3— It contains a resin (A1) having the structural unit (a3) represented by 1). The resin (A1) is preferably a copolymer.

[0015] · Unit (al)

The structural unit (al) is a structural unit from which hydroxystyrene power is also derived.

In the structural unit (al), the “structural unit in which hydroxystyrene force is also induced” includes a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene and a hydroxystyrene derivative (monomer).

Here, the “hydroxystyrene derivative” maintains at least a benzene ring and a hydroxyl group bonded thereto. For example, a hydrogen nuclear atom bonded to the α-position of hydroxystyrene, a halogen atom, or a carbon atom having 1 to 5 carbon atoms. Those substituted with other substituents such as a lower alkyl group and a halogenated alkyl group, and those having a lower alkyl group having 1 to 5 carbon atoms bonded to the benzene ring to which the hydroxyl group of hydroxystyrene is bonded, Benzene rings to which hydroxyl groups are bonded further include those having 1 to 2 hydroxyl groups bonded (the total number of hydroxyl groups is 2 to 3 at this time).

Examples of the halogen atom include a chlorine atom, a fluorine atom, and a bromine atom, and a fluorine atom is preferable. The “a-position of hydroxystyrene” means a carbon atom to which a benzene ring is bonded unless otherwise specified.

Preferred examples of the structural unit (al) include structural units (al 1) represented by the following general formula (al-1).

[0016] [Chemical 2]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; IT represents a lower alkyl group having 1 to 5 carbon atoms; p represents an integer of 1 to 3; q represents 0 or Represents an integer from 1 to 2. ]

[0017] The alkyl group of R is preferably a lower alkyl group, and is an alkyl group having 1 to 5 carbon atoms. In addition, straight chain or branched chain alkyl groups are preferred, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. Is mentioned. Of these, a methyl group is preferred industrially.

The fluorinated alkyl group is preferably a fluorinated lower alkyl group, in which part or all of the hydrogen atoms of the above-described lower alkyl group having 1 to 5 carbon atoms are substituted with fluorine atoms. In the present invention, it is preferable that all hydrogen atoms are fluorinated. The fluorinated lower alkyl group is preferably a trifluoromethyl group, hexafluoroethyl group, heptafluoropropyl group, nonafluorobutyl, which is preferably a linear or branched fluorinated lower alkyl group. Most preferred is a trifluoromethyl group (one CF), which is more preferred

Three

That's right.

R is more preferably a hydrogen atom or a hydrogen atom that is preferably a methyl group.

[0018] Examples of the lower alkyl group having 1 to 5 carbon atoms of R ² include those similar to the lower alkyl group of R. q is 0 or an integer of 1 to 2. Of these, q is preferably 0 or 1. Particularly, it is preferably 0 from an industrial viewpoint.

The substitution position of R ² is when q is 1. Any of 1-position, m-position and p-position is acceptable. Furthermore, when q is 2, any substitution position can be combined.

p is an integer of 1 to 3, preferably 1.

The substitution position of the hydroxyl group may be any of the o-position, m-position and p-position when p is 1. The p-position is preferred because it is readily available and inexpensive. Furthermore, when p is 2 or 3, any substitution position can be combined.

As the structural unit (al), one type or a mixture of two or more types can be used.

During榭脂(A1), the proportion of the structural unit (al) is based on all the structural units that constitute the榭脂(A1), 20 to 80 mole ^_0/0, it is preferred instrument 25 to 70 mole ⁰ / ₀ is it is most preferably a more preferred device 30-6 5 more preferably fixture 30 to 60 mole% that is mol%. Within this range, moderate alkali solubility is obtained when a resist composition is obtained, and the balance with other structural units is good.

[0020] · Structural unit (a2)

The structural unit (a2) is a structural unit having an acid dissociable, dissolution inhibiting group.

Preferred examples of the structural unit (a2) include the structural unit (a21) represented by the following general formula (a2-1) and the structural unit (a22) represented by the following general formula (a2-2). it can.

[0021] [Chemical 3]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R ′ represents an acid dissociable, dissolution inhibiting group. ]

[Chemical 4]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; represents a lower alkyl group having 1 to 5 carbon atoms; p represents an integer of 1 to 3; q represents 0 or 1 Represents an integer of ˜2; R ⁴ represents an acid dissociable, dissolution inhibiting group. ]

In the above general formulas (a2-1) and (a2-2), R ³ and R ⁴ each represent an acid dissociable, dissolution inhibiting group.

The acid dissociable, dissolution inhibiting group can be appropriately selected from among many proposed resins for resist compositions such as for KrF excimer laser and ArF excimer laser. For example, a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl group, or a chain or cyclic tertiary alkyl group can be preferably exemplified.

[0024] The chain tertiary alkoxycarbo group preferably has 4 to 10 carbon atoms, more preferably 4 to 8 carbon atoms. Specific examples of the chain-like tertiary alkoxy carbo group include a tert butoxy carbo yl group and a tert-amyloxy carbo ol group.

The chain tertiary alkoxy carboalkyl group preferably has 4 to 8 carbon atoms, more preferably 4 to 8 carbon atoms. Specific examples of the chain-like tertiary alkoxycarbonylalkyl group include a tert-butoxycarboromethyl group, a tert-amyloxycarboromethyl group, and the like.

The chain-like tertiary alkyl group preferably has 4 to 10 carbon atoms, and more preferably 4 to 8 carbon atoms. Specific examples of the chain tertiary alkyl group include a tert butyl group and a tert-amyl group.

A cyclic tertiary alkyl group is a monocyclic or polycyclic monovalent saturated hydrocarbon group containing a tertiary carbon atom on the ring. Specific examples of the cyclic tertiary alkyl group include 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1 Examples thereof include an ethylcyclohexyl group, a 2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, and the like.

[0025] The acid dissociable, dissolution inhibiting group contains the above-described chained tertiary alkoxycarbonyl group, chained tertiary alkoxycarbonylalkyl group, or chained or cyclic tertiary alkyl group, Heat resistance is improved.

Among these acid dissociable, dissolution inhibiting groups, a chain tertiary alkyl group is particularly preferred from the viewpoint of resolution, and a tert-butyl group is more preferred.

In the present invention, the following general formula (I) can be preferably exemplified as an acid dissociable, dissolution inhibiting group.

[0027] [Chemical 5]

R ⁵

I

R ⁶

[Wherein X represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or a lower alkyl group;

R ⁵ represents a hydrogen atom or a lower alkyl group, or X and R ⁵ may be each independently an alkylene group having 1 to 5 carbon atoms, and the end of X and the end of R ⁵ may be bonded; R ⁶ represents a hydrogen atom or a lower alkyl group. ]

[0028] Here, the term "aliphatic" in the present specification and claims is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity. The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity and may be either saturated or unsaturated, but is usually preferably saturated. .

[0029] The aliphatic cyclic group of X is a monovalent aliphatic cyclic group. Many aliphatic cyclic groups have been proposed for conventional KrF resists and ArF resists, and can be selected and used as appropriate.

Specific examples of the aliphatic cyclic group include an aliphatic monocyclic group having 5 to 7 carbon atoms and an aliphatic polycyclic group having 7 to 16 carbon atoms.

As an aliphatic monocyclic group having 5 to 7 carbon atoms, one hydrogen atom from a monocycloalkane is substituted. Excluded groups are exemplified, and specific examples include a group obtained by removing one hydrogen atom from cyclopentane, cyclohexane and the like.

Examples of the aliphatic polycyclic group having 7 to 16 carbon atoms include groups in which one hydrogen atom has been removed from bicycloalkane, tricycloalkane, tetracycloalkane, etc., specifically, adamantane, Examples include groups in which one hydrogen atom has been removed from a polycycloalkane such as norbornane, isobornane, tricyclodecane, and tetracyclododecane. Of these, an adamantyl group, a norbornyl group, and a tetracyclododeyl group are preferred industrially, and an adamantyl group is particularly preferred.

[0030] Examples of the aromatic cyclic hydrocarbon group for X include aromatic polycyclic groups having 10 to 16 carbon atoms. Specific examples include groups in which one hydrogen atom has been removed from naphthalene, anthracene, phenanthrene, pyrene, and the like. More specifically, 1 naphthyl group, 2-naphthyl group, 1 anthracenyl group, 2-anthracyl group, 1-phenanthryl group, 2-phenanthryl group, 3 phenanthryl group, 1-pyrenyl group, etc. In particular, the 2-naphthyl group is industrially preferable.

Examples of the lower alkyl group for X include the same as the lower alkyl group for R in the above formula (al-1).

X is most preferably a methyl group, preferably a lower alkyl group, or an ethyl group, more preferably an ethyl group.

[0031] Examples of the lower alkyl group for R ⁵ include the same as the lower alkyl group for R in the above formula (al-1). Industrially, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.

R ⁶ represents a lower alkyl group or a hydrogen atom. As the lower alkyl group for R ^{6, the same as} the lower alkyl group for R ⁵ can be exemplified. R ⁶ is preferably industrially a hydrogen atom.

In the formula (I), X and R ⁵ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of X may be bonded to the end of R ⁵ .

In this case, in the formula (I), R ⁵ , X, an oxygen atom to which X is bonded, and a carbon atom to which the oxygen atom and R ⁵ are bonded form a cyclic group. The cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydrovinyl group and a tetrahydrofuranyl group.

[0033] As the acid dissociable, dissolution inhibiting group (I), a group in which R ⁶ is a hydrogen atom is particularly preferable because of excellent effects of the present invention.

Specific examples thereof include, for example, a group in which X is a lower alkyl group, that is, 1 alkoxyalkyl group includes 1-methoxyethyl group, 1-ethoxyethyl group, 1-isopropoxycetyl group, 1 n butoxychetyl group, 1 tert butoxystilyl Group, methoxymethyl group, ethoxymethyl group, isopropoxymethyl group, n-butoxymethyl group, tert-butoxymethyl group and the like.

In addition, the group in which X is an aliphatic cyclic group includes 1-cyclohexyloxychetyl group, (2 adamantyl) oxymethyl group, and 11 (1 adamantyl) oxyscheyl represented by the following formula (Π-a). Groups and the like.

Examples of the group in which X is an aromatic cyclic hydrocarbon group include a 11- (2-naphthyl) oxetyl group represented by the following formula (Π-b).

Among these, 1 ethoxyethyl group is particularly preferable.

[0034] [Chemical 6]

[0035] The acid dissociable, dissolution inhibiting group in the present invention includes a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl group, a chain or cyclic tertiary alkyl group, and the above general formula. (I) Force Group power At least one selected is preferably used. Among them, it is most preferable to contain, as a main component, the above general formula (I), which is more preferable.

Here, “contained as the main component” means that acid dissociable dissolution suppression contained in rosin (A1) It means 50 mol% or more of the group, preferably 70 mol% or more, and more preferably 80 mol% or more.

[0036] Note that R in the structural units (a21) and (a22) is the same as R in the general formula (al-1).

R ² in the structural unit (a22) is Ru include the same as R ² in formula (al- 1).

In addition, p and q in the structural unit (a22) are the same as p and q in the general formula (al-1), respectively.

As the structural unit (a2), one type or a mixture of two or more types can be used.

The proportion of structural unit (a2) in rosin (A1) is preferably 5 to 70 mol% with respect to all the structural units constituting rosin (A1). 5 to 55 mol% is more preferable, and 5 to 55 mol% is most preferable. By setting the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit value or less, the balance with other structural units is good.

[0038] Further, the structural unit (a2) is, when it is the structural unit (a21), relative to the total structural units constituting the榭脂(A1), preferably to be 5 to 70 mole ^_0/0 it is most preferred that the ingredients 5 to 50 mole ⁰ / is that force Ri preferably fixture 5-30 mol% is _zero is further preferred tool 5 to 20 mol%. By setting it to the lower limit or higher, a good resist pattern can be obtained when the resist composition is used, and by setting the upper limit or lower, the balance with other structural units is good.

Further, the structural unit (a2) is, when the a structural unit (a22), relative to the total structural units constituting the榭脂(A1), 5 to 70 mole ^_0/0, it is preferred instrument 10 65 mole ^_0/0 Dearuko and is still more preferably tool 30-55 Dearuko mol% and most preferably more preferably fixture 20 to 60 mol%. By setting it to the lower limit value or more, a good resist pattern can be obtained when the resist composition is used, and by setting it to the upper limit value or less, the balance with other structural units is good.

[0039] · Structural unit (a3)

The structural unit (a3) is a structural unit represented by the general formula (a3-1). In the formula (a3-1), A represents a single bond or a divalent organic group.

In the structural unit (a3), an “organic group” 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 (fluorine atom, chlorine atom, etc.) Etc.)

The organic group is more preferably a linear or branched saturated hydrocarbon group, which is preferably a linear, branched or cyclic saturated hydrocarbon group. The saturated hydrocarbon group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. The saturated hydrocarbon group may have a substituent. Examples of the substituent include, but are not limited to, halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, and linear, branched or cyclic alkyl groups having 1 to 6 carbon atoms.

Here, “having a substituent” means that part or all of the hydrogen atoms of the saturated hydrocarbon group are substituted with a substituent.

Examples of the organic group also include groups in which some of the carbon atoms of the saturated hydrocarbon group as described above are substituted with a hetero atom such as an oxygen atom, a nitrogen atom, or a sulfur atom.

[0040] The organic group is particularly preferably a divalent saturated hydrocarbon group.

As the saturated hydrocarbon group, an alkylene group is particularly preferable. The saturated hydrocarbon group may be linear, branched or cyclic.

Examples of the linear or branched alkylene group include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, a pentylene group, an isopentylene group, and a neopentylene group.

The cyclic alkylene group includes a cyclic group obtained by removing two hydrogen atoms from a saturated hydrocarbon ring such as cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, and tetracyclododecane. And a group in which a linear or branched alkylene group is bonded to the group.

As the saturated hydrocarbon group, a linear alkylene group, preferably a linear or branched alkylene group, is more preferable, and an ethylene group or a propylene group is particularly preferable.

A is particularly preferably a single bond.

In the formula (a3-1), Ar represents an arylene group which may have a substituent, and excludes the substituent Examples of the basic ring include a phenylene group and a naphthylene group. Among these, a phenylene group is preferable.

Examples of the substituent include a linear or branched alkyl group having 1 to 4 carbon atoms. Among these, Ar is preferably an arylene group having no substituent.

R may be the same as R in the general formula (al-1).

Examples of the acid dissociable, dissolution inhibiting group for R ¹ include a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl group, a chain or cyclic tertiary alkyl group exemplified in the structural unit (a2). And at least one selected from the group force represented by the general formula (I) force is preferably used, and the preferable one among them is the same as in the structural unit (a2).

As the structural unit (a3), one type or a mixture of two or more types can be used.

The proportion of structural unit (a3) in rosin (A1) is preferably 3 to 25 mol%, preferably 1 to 30 mol%, based on all the structural units constituting rosin (A1). Most preferred is 5 to 20 mol%. By setting it within the above range, the standing wave suppression effect is extremely excellent.

[0043] · Unit (a4)

The resin (Al) may further have a structural unit (a4) that also induces styrene power. In the present invention, the structural unit (a4) is not essential, but when it is contained, the heat resistance can be improved when a resist composition is formed.

In the structural unit (a4), the “structural unit derived from styrene catalyst” includes a structural unit obtained by cleaving the ethylenic double bond of styrene and a styrene derivative (excluding hydroxystyrene). It shall be.

Here, the “styrene derivative” is a hydrogen atom bonded to the α-position of styrene, a hydrogen atom substituted with other substituents such as a halogen atom, an alkyl group, an alkyl halide group, and the hydrogen of the styrene group. Nuclear power, and those substituted by a substituent such as a lower alkyl group having 1 to 5 carbon atoms are included.

Examples of the halogen atom include a chlorine atom, a fluorine atom, and a bromine atom, and a fluorine atom is preferable.

Note that “α-position of styrene” means the carbon to which the benzene ring is bonded unless otherwise specified. An atom.

[0044] Preferred examples of the structural unit (a4) include the structural unit (a41) represented by the following general formula (a4-1).

[0045] [Chemical 7]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; IT represents a lower alkyl group having 1 to 5 carbon atoms; q represents 0 or an integer of 1 to 2; ]

[0046] R and R ^2, the general formula (al- 1) from each other similar to the R and R ² are exemplified et be.

q is 0 or an integer of 1 to 2. Of these, q is preferably 0 or 1. Particularly, it is preferably 0 from an industrial viewpoint.

The substitution position of R ² is when q is 1. Any one of the 1-, m-, and p- positions can be used. When q is 2, any substitution position can be combined.

As the structural unit (a4), one type or a mixture of two or more types can be used.

When rosin (A1) contains structural unit (a4), the proportion of structural unit (a4) is preferably 1 to 25 mol% with respect to all structural units constituting rosin (A1). Most preferred is 5 to 20 mole percent, with 25 mole percent being more preferred. Within such a range, when the resist composition is used, the heat resistance effect is enhanced and the lance with other structural units is also good.

[0048] The resin (A1) does not impair the effects of the present invention! /, Within the scope, other constituents other than the essential constituent units (al) to (a3) and preferably contained constituent units (a4) Including the unit. The structural units that can be used are not limited to the above-mentioned essential structural units (al) to (a3), and other structural units that are not preferably classified as structural units (a4). For KrF positive excimer lasers As a resist resin for ArF excimer laser and the like, a number of conventionally known ones can be used. However, for the effect of the present invention, it is preferable that the resin (A1) is a resin mainly composed of the structural units (al) to (a3).

Here, “main component” means that the total of structural units (al) to (a3) occupies 70 mol% or more of all the structural units constituting rosin (A1), preferably 80 mol % Or more, more preferably 90 mol% or more. Most preferred is a resin that also has a structural unit (al to (a3) force.

[0050] The mass average molecular weight (Mw; converted to positive styrene by gel permeation chromatography (GPC), the same shall apply hereinafter) of the resin (A1) is 1000 to 100000 force S preferred <, 5000 to 500 00 force. <<7000-20000 is the most preferred! / \

When the mass average molecular weight is 100000 or less, the resolution is high when a resist composition is prepared, and it is particularly suitable for thin film implantation. On the other hand, when it is 1,000 or more, it is suitable for a thin film implantation particularly because it has high heat resistance when used as a resist composition.

In other words, in the implantation process, the resist pattern on the substrate is heated due to the exothermic effect of the implantation of impurities, so that the resist pattern undergoes shape change or certain components in the resist pattern are gasified and processed. Force that may cause a problem of lowering the degree of vacuum in the room High heat resistance makes it suitable for such processes.

In addition, the smaller the degree of dispersion (MwZMn (Mn: number average molecular weight)) of rosin (A1) is, the better the resolution is when using a resist composition, which is preferable. The dispersity is preferably 1.1 to 5.0, more preferably 1.1 to 3.0, and most preferably 1.1 to 2.5.

[0051] The resin (A1) is obtained by polymerizing a monomer for deriving each structural unit by a conventional method, for example, a known radical polymerization using a radical polymerization initiator such as azobisisobutyl-tolyl (AIBN). Therefore, it can be obtained.

For example, rosin (A1) can be produced as follows.

First, a precursor polymer of rosin (A1) is produced by known radical polymerization, etc., followed by the elimination reaction of the protective group of the precursor polymer, and in some cases, a protective group that is eliminated by the action of an acid. To obtain rosin (A1). [0052] The method for producing the precursor polymer includes a monomer in which the phenolic hydroxyl group of the monomer for deriving the structural unit (al) is protected with a acetyl group, a monomer for deriving the structural unit (a2), and a structural unit (a3). The monomer and the polymerization initiator are dissolved in an organic solvent, held at an appropriate temperature for an appropriate time, and radically polymerized for production.

As the organic solvent to be used, a solvent capable of dissolving any of the above monomers, polymerization initiators and the obtained polymer is preferable. For example, dioxane, isopropyl alcohol, acetone, tetrahydrofuran, 2-butanone, 4-methyl-2-pentanone, etc. Can be mentioned.

Examples of the polymerization initiator to be used include azobis compounds such as azobisisobutyrate-tolyl, 2,2'-azobis (2,4 dimethylvale-tolyl), and organic peroxides such as benzoyl peroxide. Etc.

The polymerization temperature is usually preferably in the range of 50 to 150 ° C, and the polymerization time is preferably 1 to LO time, more preferably about 2 hours or more. Outside the above range, inconveniences such as low yield occur.

The precursor polymer solution obtained in this way is poured into a large amount of poor solvent such as methanol, isopropyl alcohol, water and the like to be deposited. Thereafter, the precipitate is filtered and sufficiently dried to obtain a precursor polymer of rosin (A1).

Further, in some cases, purification for removing unreacted monomers remaining in the precursor polymer, a polymerization initiator or the like can be performed by a usual method such as a reprecipitation method.

[0053] The method for carrying out the elimination reaction of the protecting group of the precursor polymer obtained by the above-mentioned method involves dissolving the precursor polymer in an organic solvent and adding an acidic compound and Z or a basic compound. Then, hold the temperature at an appropriate temperature for an appropriate time.

The organic solvent used is preferably a solvent that can dissolve the deviation of the precursor polymer and the obtained resin (A1), such as dioxane and tetrahydrofuran. Examples of the acidic compound used include hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, and nitric acid, and hydrochloric acid is more preferably used.

Examples of the basic compound used include ammonia, hydrazine, caustic soda and the like, and hydrazine is more preferably used. The amount of acidic compound and z or basic compound used is usually 1.0 to 3.0 equivalents with respect to the protecting group for the phenolic hydroxyl group contained in the precursor polymer. Preferably 1.0 to: L is 5 equivalents.

The temperature of the elimination reaction is usually preferably in the range of 10 to 50 ° C, and the reaction time is preferably 1 to: LO time, more preferably about 2 hours or more.

The solution of the resin (A1) obtained in this way is poured into a large amount of poor solvent such as water to precipitate it. Thereafter, the precipitate is filtered and sufficiently dried to obtain rosin (A1). In some cases, purification can be performed by a usual method such as a reprecipitation method.

[0054] Further, in some cases, when a protecting group that is eliminated by the action of an acid is introduced into rosin, a known method can be used depending on the type of the protecting group to be introduced, but the protecting group is O-alkyl. In the case of a xyalkyl group, the resin obtained by the above method and a beryl ether compound that induces a protecting group are dissolved in an organic solvent, an acidic compound is added, and the resin is applied at an appropriate temperature. Hold for a long time and react to produce.

Examples of the organic solvent used include dioxane and tetrahydrofuran.

Examples of the acidic compound used include p-toluenesulfonic acid monohydrate, hydrochloric acid, sulfuric acid and the like.

The reaction temperature is usually preferably in the range of 0 to 50 ° C. The reaction time is preferably 15 minutes to 10 hours. If the reaction is carried out outside the above range, the yield will be low.

The solution thus obtained is poured into an aqueous alkali solution or an aqueous solution for precipitation, and then the precipitate is filtered and dried to obtain a resin (A1).

In some cases, purification can be performed by a usual method such as a reprecipitation method.

[0055] Among the structural units constituting the resin (A1), the structural unit (a3) having a functional group (SO 3) that absorbs exposure light is represented by the following general formula (a3-0). Induced by the monomer represented

2

It is.

[0056] [Chemical 8]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R ¹ represents a hydrogen atom or an acid dissociable, dissolution inhibiting group; A represents a single bond or a divalent organic group. Ar represents an arylene group which may have a substituent. ]

[0057] Formula (A3- 0) in, A, Ar and R ¹ are, A in formula (A3- 1), and Ar and R ¹ their respective include those similar.

[0058] The method for producing the monomer represented by the general formula (a3-0) is obtained by adding R ^{1 of the} monomer represented by the general formula (a3-0) to the compound represented by the following general formula (Z). To produce a precursor, followed by (meth) acrylic acid halide, α-fluoroacrylic acid halide, etc. that induces the structure represented by the general formula (a3-0). Produced by reacting acid halides.

(Meth) acrylic acid means one or both of acrylic acid and methacrylic acid. (Meth) acrylic acid halide means one of acrylic acid halide and methacrylic acid halide! / ヽ means both.

[0059] [Chemical 9]

HO-A-Ar- S0 ₂ -Ar-OH '' ■ (Z)

[Wherein, A and Ar are the same as A and Ar in the general formula (a3-1), respectively. ]

[0060] The method of introducing the substituent R ¹ in the compound represented by the general formula (Z), the force R ¹ which may be used publicly known methods Te cowpea to the structure of R ¹ is a- alkoxyalkyl In the case of a group, the compound represented by the general formula (Z) and the vinyl ether compound that derives the substituent R ¹ are dissolved in an organic solvent, and an acid compound is added to the compound. Produced by reacting at temperature for an appropriate time.

Examples of the organic solvent used include dioxane and tetrahydrofuran. It is.

Examples of acidic compounds used include p-toluenesulfonic acid monohydrate, hydrochloric acid and sulfuric acid.

The reaction temperature is usually preferably in the range of 0-50 ° C. The reaction time is preferably 15 minutes to 10 hours. If the reaction is carried out outside the above range, the yield will be low.

The solution thus obtained is poured into an excess of aqueous caustic soda solution and precipitated. Thereafter, the precipitate is separated by filtration, and further treated by a known method such as extraction or crystallization to obtain a monomer precursor that provides the structural unit (a3).

[0061] In the method of reacting an acid halide with a monomer precursor, the precursor and a basic compound are dissolved in an organic solvent to induce the structure represented by the general formula (a30). The product is prepared by adding an acid halide such as a halogenated compound, a halogenated compound, or a fluoroacrylic acid halide, and maintaining the reaction at an appropriate temperature for an appropriate time.

Examples of the organic solvent used include tetrahydrofuran, dioxane, acetone, 2-butanone and the like.

The basic compound used is preferably a tertiary organic amine such as triethylamine. The reaction temperature is usually preferably in the range of 0-50 ° C. The reaction time is preferably 15 minutes to 10 hours. If the reaction is carried out outside the above range, the yield will be low.

The solution thus obtained is poured into excess water and precipitated. Thereafter, the precipitate is separated by filtration and treated by a known method such as extraction or crystallization to obtain a monomer that provides the structural unit (a3).

[0062] In the positive resist composition of the present invention, the component (A) includes the resin (A1), and the following resins (A2) to (A4) other than the resin (A1) are used in combination. You can let it go!

[0063] 'Orea (A2)

In the resin (A2), the structural unit (all) and the acid dissociable, dissolution inhibiting group of the structural unit (a22) are substituted with the acid dissociable, dissolution inhibiting group represented by the general formula (I). ! A resin component having a constituent unit, which does not contain the constituent unit (a3).

[0064] Of all the structural units that constitute the榭脂(A2), the structural unit (al l) may further be 20 to 85 mole ^_0/0 der Rukoto is preferred tool 30 to 80 mol% This is 45 to 80 mol% And are most preferred.

Of all the structural units constituting the resin (A2), the acid dissociable, dissolution inhibiting group of the structural unit (a22) is substituted with the acid dissociable, dissolution inhibiting group represented by the general formula (I)! The structural unit is preferably 5 to 60 mol%, more preferably 15 to 55 mol%, even more preferably 20 to 50 mol%, most preferably.

When other structural units such as the structural unit (a4) are used, the content is preferably 10 mol% or less. That is, other structural units such as the structural unit (a4) are preferably 0 to 10 mol%.

[0065] 'Orea (A3)

mm (A3) is an acid dissociable, dissolution inhibiting group in which the structural unit (all) and the acid dissociable, dissolution inhibiting group of the structural unit (a22) are tertiary alkyloxycarbonyl groups. A resin component having a structural unit that is substituted, and does not include the structural unit (a3).

The tertiary alkyloxycarbonyl group is preferably a tertiary alkyloxycarboxyl group having a carbon number power of ˜8 of the tertiary alkyloxy group, and a specific example thereof is tert-butyloxy. Examples thereof include a carbo group and a tert-amyloxy carbo group.

[0066] Of all the structural units that constitute the榭脂(A3), the structural unit (al l) may further be 20 to 85 mole ^_0/0 der Rukoto is preferred tool 30 to 80 mol% It is most preferably 45 to 80 mol%.

Of all the structural units constituting the resin (A3), the acid dissociable, dissolution inhibiting group of the structural unit (a22) is substituted with an acid dissociable, dissolution inhibiting group, such as a tertiary alkyloxycarboxyl group. The constituent unit is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and most preferably 15 to 45 mol%.

[0067]-(A4) The resin (A4) is a resin component having the structural unit (al 1), the structural unit (a21), and the structural unit (a4), and not including the structural unit (a3). A resin component obtained by replacing the acid dissociable, dissolution inhibiting group of the structural unit (a21) with an acid dissociable, dissolution inhibiting group such as a tertiary alkyl group.

The tertiary alkyl group is preferably a tertiary alkyl group having 4 to 12 carbon atoms, and specific examples include a chain tertiary alkyl group such as a tert butyl group or a tert-amyl group; Tertiary alkyl groups including polycyclic alicyclic hydrocarbon groups such as methyl-adamantyl group, 2-ethyladamantyl group, etc .; 1-ethylcyclohexyl, 1-ethylcyclopentyl group, 1-methylcyclohexyl And tertiary alkyl groups including monocyclic alicyclic hydrocarbon groups such as 1-methylcyclopentyl group. Of these, a chain-like tertiary alkyl group is more preferred.

[0068]榭脂(A4) of the total structural units constituting the structural unit (al l) may further be 20 to 80 mole ^_0/0 der Rukoto a preferred tool 30 to 75 mol% It is most preferably 45 to 75 mol%.

Of all the structural units that constitute the榭脂(A4), the structural unit (a21) 5 to 60 mole ^_0/0, it is further preferred instrument 10 it is preferred tool 40 mol% Most preferably, it is 30 mol%.

Of all the structural units that constitute the榭脂(A4), the structural unit (a4), 1 to 30 mol ^_0/0 Dearuko and force transducer preferred, more preferred instrument 5 5 to 30 mol% Most preferably, it is ˜20 mol%.

[0069] The proportion of the above-described rosin (A1) in the component (A) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and more preferably 15 to 40% by mass. By setting it to the lower limit value or more, reflected light from the substrate of exposure light is sufficiently absorbed, and the effect of reducing SW is improved. By setting it to the upper limit value or less, the absorption of exposure light is controlled, and the resolution is improved.

The proportion of the above-mentioned rosin (A2) in the component (A) is most preferably 30 to 50% by mass, preferably 5 to 60% by mass, more preferably 20 to 60% by mass.

The proportion of the above-mentioned rosin (A3) in the component (A) is most preferably 25 to 50% by mass, preferably 5 to 60% by mass, more preferably 20 to 60% by mass. The proportion of the above-mentioned rosin (A4) in the component (A) is most preferably 40 to 70% by mass, preferably 30 to 70% by mass, preferably 5 to 80% by mass.

[0070] Among these, it is possible to use a mixed resin of resin (A1), resin (A2) and resin (A3), or a mixed resin of resin (A1) and resin (A4). In addition, it is preferable because lithography properties such as resolution are improved.

[0071] <(B) component>

The component (B) is not particularly limited, and any component that has been proposed as an acid generator for chemical amplification resists can be used.

Examples of such acid generators include onium salt-based acid generators such as iodine salts and sulfo-um salts, oxime sulfonate-based acid generators, bisalkyl or bis-aryl sulfo-diazomethanes, A wide variety of acid generators such as diazomethane acid generators such as poly (bissulfol) diazomethanes, nitrobenzil sulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators are known.

[0072] The onion salt-based acid generator is an acid generator (B1) represented by the following general formula (B1) [hereinafter, referred to as component (B1). ].

[0073] [Chemical 10]

[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, a halogen atom, a linear or branched group; A chain or cyclic alkyl group, a halogenated alkyl group or an alkoxy group; R ⁵³ is an aryl group which may have a substituent; and n is an integer of 1 to 3. In the general formula (B1), 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.

The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. In particular, all the hydrogen atoms are fluorine atoms. The strength of the substitute is preferred because the strength of the acid increases.

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

R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, a linear, branched or cyclic alkyl group.

, A straight-chain or branched-chain halogenoalkyl group, or a straight-chain or branched-chain 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 linear or branched alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

In R ⁵² , the cyclic alkyl group is most preferably 4 to 10 carbon atoms, preferably 4 to 12 carbon atoms, more preferably 5 to 5 carbon atoms: LO.

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 herein are the same as the “linear or branched alkyl group” in R ⁵² . Examples of the halogen atom to be substituted include the same as those described for the “halogen atom” in R ⁵² above.

In the halogenated alkyl group, it is preferred that 50 to 100% of the total number of hydrogen atoms are substituted with halogen atoms, and it is more preferred 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, a hydrogen atom is preferable.

[0076] ^R53 is an aryl group which may have a substituent, and examples of the basic ring structure excluding the substituent include a naphthyl group, a phenyl group, and an anthracene group. From the viewpoint of the effect of the invention and absorption of exposure light such as ArF excimer laser, a phenol group is preferred! 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.

n is an integer of 1 to 3, 2 or 3 is preferred and 3 is particularly preferred

[0077] Preferable examples of the acid generator (B1) include the following.

[0078] [Chemical 11]

[0079] Among them, a compound represented by the following chemical formula (b-0-1) or (b-0-2) is preferable.

[0080] [Chemical 12]

CF ₃ (CF ₂ ) ₃ SO,-

[0081] Further, examples of the form salt acid generator include compounds represented by the following general formula (b-1) or (b-2).

[0082] [Chemical 13]

… (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 a group; at least one of,, ~ "represents an aryl group; at least one of R ⁵ " to R ⁶ "represents an aryl group. ]

In the formula (b-1), R ^{lw to} R ³ ″ each independently represents an aryl group or an alkyl group.

,, ~ "At least one represents an aryl group. It is preferred that two or more of,, ~" are aryl groups. R ^lw- R ³ "must be allele groups. Is most preferred

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 or may not be substituted with a group, a halogen atom or the like.

As the aryl group, an aryl group having 6 to L0 carbon atoms is preferred because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.

Although the hydrogen atom of the aryl group is substituted, the alkyl group is preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, preferably an alkyl group having 1 to 5 carbon atoms. Most preferred to be.

Even if the hydrogen atom of the aryl group is substituted, the alkoxy group is most preferably a methoxy group or an ethoxy group, preferably an alkoxy group having 1 to 5 carbon atoms.

Even if the hydrogen atom of the aryl group is substituted, the halogen atom is preferably a fluorine atom.

The alkyl group of “˜” is not particularly limited, for example, a straight chain having 1 to 10 carbon atoms. And a branched or cyclic alkyl group. Among these, from the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5. Specifically, methyl, ethyl, n-propyl, isopropyl, _n -butyl, isobutyl, _n -pentyl, cyclopentyl, hexyl, cyclohexyl, nonyl, de- And the like. Among them, the methyl group is preferred because it can be synthesized at a low cost.

Among these, it is most preferable that R ^{LW to} R ³ ″ are all phenyl groups.

[0084] R ⁴ "represents a linear, branched or cyclic alkyl group or fluorinated alkyl group.

Most preferably, the linear or branched alkyl group has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 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.

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

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

At least one of R ⁵ "to R ⁶ " represents an aryl group. All of R ⁵ "to R ⁶ " are preferably aryl groups.

Examples of the aryl group of R ⁵ "to _R ⁶ , include those similar to the aryl group of R1" to _r ³ ".

Examples of the alkyl group for R ⁵ "to R ⁶ " include the same alkyl groups as for,, to ".

Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenol groups. "The, R ⁴ in the formula (b- 1)" R ⁴ of formula (b-2) in the same groups as those described above for. [0086] Specific examples of the onion salt-based acid generator represented by the above general formula (b-1) or (b-2) include trifluoromethanesulfonate, nonafluorobutanesulfonate, bis (4 --Tert-butylphenol) Jodonium trifluoromethanesulfonate or nonafluorobutane sulfonate, trifluorosulfuron trifluoromethanesulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate, tri ( 4-methylphenol) sulfo-trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfotrifluoromethanesulfonate, That heptafluoro Pan sulfonate or its nonafluorobutane sulfonate, monophenyl dimethyl sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, diphenyl monomethyl sulfone Trifluoromethanesulfonate, heptafluorine propane sulfonate or nonafluorobutane sulfonate, (4 methylphenol) diphenylsulfotrifluoromethane sulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate , (4-methoxyphenyl) diphenyl sulfone trifluoromethanesulfonate, heptafluoropropanosulfonate or nonafluorobutanesulfonate, tri (4-t ert butyl) phenol sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate,

Examples thereof include trifluoromethanesulfonate of diphenyl [1 (4-methoxy) naphthyl] sulfo, heptafluoropropane sulfonate or nonafluorobutane sulfonate thereof.

It is also possible to use ohmic salts in which the ionic part of these ohmic salts is replaced by methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate. .

[0087] In the general formula (b-1) or (b-2), the key-on part is a key-on represented by the following general formula (b-3) or (b-4). (The force chain part is the same as (b-1) or (b-2)). [0088] [Chem. 14]

[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.

[0089] 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 "is preferably as small as possible because it has good solubility in the resist solvent within the above carbon number range.ヽ.

In addition, in the alkylene group of X "or the alkyl group of Υ" and Ζ ", the greater the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength and the higher the energy level of 200 nm or less. This is preferable because transparency to light and electron beams is improved.

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 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

[0090] In the present invention, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), which generates an acid upon irradiation with radiation. It is what has.

Such oxime sulfonate acid generators are used for chemically amplified resist compositions. Since it is frequently used, it can be arbitrarily selected and used.

[0091] [Chemical 15]

• ■ ■ (B-l)

[In the formula (B-1), R ²¹ and R ²² each independently represents an organic group. ]

In the present invention, the organic group is a group containing a carbon atom, and is 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 ²¹ , 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. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable.

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 of the hydrogen atoms are halogen atoms. An alkyl group substituted with an atom.

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. In other words, the halogenated alkyl group is preferably a fluorinated alkyl group! /.

The aryl group has 4 to 20 carbon atoms that are preferred 4 to: 6 to 1 carbon atoms that L0 is more preferred 0 is most preferred. 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 replaced by a halogen atom, and a completely halogenated aryl group means that all hydrogen atoms are halogen atoms. An aryl group substituted with an atom.

As R ²¹ , in particular, an alkyl group having 1 to 4 carbon atoms which has no substituent, or 1 carbon atom

~ 4 fluorinated alkyl groups are preferred.

[0093] The organic group for R ²² is preferably a linear, branched or cyclic alkyl group, aryl group or cyan group. Examples of the alkyl group and aryl group for R ²² include the same alkyl groups and aryl groups as those described above for R ²¹ .

R ²² 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.

[0094] As the oxime sulfonate-based acid generator, more preferred are those represented by the following general formula (

Examples thereof include compounds represented by B-2) or (B-3).

[0095] [Chemical 16]

[In the formula (B-2), R ^dl is a cyano group, an alkyl group having no substituent, or a halogenalkyl group. R ³² is an aryl group. R ³³ is an alkyl group having no substituent or a halogenated alkyl group. ]

[Chemical 17]

[In the formula (B-3), R ³⁴ represents a cyano group, an alkyl group having no substituent, or a halogen group. It is an alkyl group. R ³⁵ is a divalent or trivalent aromatic hydrocarbon group. R ³⁶ is an alkyl group having no substituent or a halogenated alkyl group. p is 2 or 3. [0097] In the general formula (B-2), the alkyl group or the halogenated alkyl group having no substituent of R ³¹ preferably has 1 to L0 carbon atoms. More preferred is 1 to 8 carbon atoms. Most preferred is 1 to 6 carbon atoms.

R ³¹ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

The fluorinated alkyl group for R ³¹ 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! /

[0098] The aryl group of R ³² includes an aromatic hydrocarbon such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, and a phenanthryl group. 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 ³² 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 8 carbon atoms, and the halogenated alkyl group is a fluorinated alkyl group. Is preferred.

[0099] The alkyl group having no substituent of R ³³ or the halogenated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms. Most preferred.

R ³³ is most preferably a partially or fully fluorinated alkyl group, which is preferably a halogenated alkyl group.

The fluorinated alkyl group in R ³³ preferably has 50% or more of the hydrogen atoms of the alkyl group fluorinated, more preferably 70% or more, and even more preferably 90% or more. This is preferable because the strength of the acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted. [0100] In the general formula (B-3), the alkyl group or the halogenated alkyl group having no R substituent is an alkyl group having no R ³¹ substituent. Or the thing similar to a halogenalkyl group is mentioned.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁵ include groups obtained by further removing one or two hydrogen atoms from the above-mentioned aryl group for R ³² .

Do no substituent of R ^36, the alkyl group or Harogeni spoon alkyl group, the same alkyl group or Harogeni spoon alkyl group containing no substituent group of the ³ mentioned et be.

p is preferably 2.

[0101] 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-cyclohex-l-acetonitrile, OC- (methylsulfo-l-uoxyimino) 1-cyclohepturacetonitrile, α (methylsulfo-l-uoxyimino) — 1-cyclooctaturacetonitrile, Trifluoromethylsulfo-luoximino) — 1-cyclopent Tert-acetonitrile, _α- (trifluoromethylsulfo-roximino) -cyclohexylhexonitrile, α (ethylsulfo-loxy) Cymino) -ethylacetonitrile, α- (propylsulfo-ruximino) -propylaceto-tolyl, _α- (cyclohexylsulfo-ruximino) -cyclopentylacetonitol, a- (cyclohexylsulfo-ruximino) -cyclohe Xylacetonitrile, a- (Cyclohexylsulfo-ruximino) — 1-Cyclopente-Lucetonitrile, a- (Ethylsulfo-Luoxyimino) — 1-Cyclopente-Lucetonitrile, α (Isopropylsulfo-Luoxyimino) — 1-Cyclopente-Luacetonitrile , A-(η-Butylsulfonyloxymino) 1-cyclopentenylrucetonitrile, α (Ethylsulfo-Luoxyimino) — 1-Cyclohexyl-Luacetonitrile, α- (Isopropylsulfoxy-imino) 1-cyclohexe Asetonitoriru, shed _(η - Buchirusuruho - Ruokishiimino) 1 Shikuro to Kise - Ruasetonitoriru, α (Mechirusuruho - Ruokishi Imino) - Hue - Ruasetonitoriru, OC - (Mechirusuruho - Ruokishiimino) -ρ- Metokishifu E - Ruasetonitoriru, α - (Torifuruoro Methylsulfo-oxyximino) -phenylacetotolyl, _α- (trifluoromethylsulfo-oxyximino) -p-methoxyphenylacetonitrile, at- (ethylsulfonyloxyximino) -p-methoxyphenylacetonitryl Α- (propylsulfo-luoxyimino) p-methylphenylacetonitrile, α (methylsulfo-luoxyimino) p-bromophenolacetonitrile, and the like.

Moreover, the compound represented by the following chemical formula is mentioned.

[Chemical 18]

CH ₉ -0 ₂ S—— O— K = C

cm

Cf = ₃ — 0 ₂ S— 0— N = »C == — O— SOj— CF ₃

ON CN

[0103] Examples of preferable compounds among the compounds represented by the general formula (B-2) or (B-3) are shown below.

[0104] [Chemical 19]

]

[0106] Of the above exemplified compounds, the following three compounds are preferred: [0107] [Chemical Formula 21]

[0108] [Chemical 22] C¾-C »HS0-(C½) 3CH3

[0109] [Chemical 23]

[0110] 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.

Poly (bissulfonyl) diazomethanes include, for example, 1,3 bis (phenylsulfol diazomethylsulfol) propane (when A = 3), 1,4 bis having the structure shown below. (Phenolsulfol diazomethylsulfol) butane (when A = 4), 1, 6 Bis (Phenolsulfol diazomethylsulfol) hexane (when A = 6), 1 , 10 Bis (fursulfol-diazomethylsulfo) decane (when A = 10), 1,2-bis (cyclohexylsulfoldiazomethylsulfol) ethane (when B = 2) ), 1,3 bis (cyclohexylsulfoldiazomethylsulfol) propane (when B = 3), 1,6 bis (cyclohexylsulfoldiazomethylsulfol) hexane (B = 6), 1, 10-bis (cyclohexylsulfol diazomethylsulfol) decane (B = (In the case of 10)).

[0111] [Chemical 24]

[0112] Among these, diazomethane-based acid generator power is excellent in the effect of the present invention and is preferable.

[0113] As the component (B), one type of these acid generators may be used alone, or two or more types may be used in combination.

The content of the component (B) in the positive resist composition of the present invention is 0.530 parts by mass, preferably 1 to L0 parts by mass with respect to 100 parts by mass of the component (A). By making it in the above range, pattern formation is sufficiently performed. Further, it is preferable because a uniform solution can be obtained and storage stability is improved.

[0114] <Component (D)>

The positive resist composition of the present invention further contains a resist pattern shape, post exposure stability of the latent image formed oy the pattern-wise exposure of the resist layer, and the like. Nitrogen organic compound (D) (hereinafter referred to as component (D)) can be blended.

Since a wide variety of components (D) have already been proposed, any known one can be used. However, aliphatic amines, particularly secondary aliphatic amines, are used. preferable.

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

Three

Examples include amines substituted with the lower alkyl group or hydroxyalkyl group (alkylamines or alkylalcoholamines). Specific examples thereof include mono-alkylamines such as n-hexylamine, n-ptylamine, n-octylamine, n-norlamin, n-decylamine; jetylamine, di-n-propylamine, di-n-ptylamine, di-n-octylamine. , Dialkylamines such as dicyclohexylamine; trimethylamine, triethylamine, tri- _n -propylamine, tri-n-butylamine, tri-n-hexyl Trialkylamines such as luamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-no-lamine, tri-n-de-ramine, tri-n-dodecylamine; diethanolamine, Examples thereof include alkyl alcohol amines such as triethanolamine, diisopropanolamine, triisopropanolamine, di- _n -octanolamine, and tri-n-octanolamine. Of these, alkyl alcoholamines and trialkylamines are preferable, and alkyl alcoholamines are most preferable. Of the alkyl alcoholamines, triethanolamine and triisopropanolamine are most preferred.

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

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

[0115] <Other optional ingredients>

In the positive resist composition of the present invention, an organic carboxylic acid is further added as an optional component for the purpose of preventing sensitivity deterioration due to the blending of the component (D) and improving the resist pattern shape, stability with time, etc. Alternatively, phosphorus oxoacid or a derivative thereof (E) (hereinafter referred to as component (E)) can be contained. In addition, the component (D) and the component (E) can be used together, or one kind of force can be used.

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

Phosphoric acid or its derivatives include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid or derivatives such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid Phosphonic acids such as n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof; phosphinic acids such as phosphinic acid, phenylphosphinic acid and their Examples include derivatives such as esters, and among these, phosphonic acid is particularly preferable.

Component (E) is used in an amount of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of component (A).

[0116] The positive resist composition of the present invention includes, as an optional component, a dissolution inhibitor (C) (hereinafter referred to as (C) It is called an ingredient. ) May be included.

As the component (C), those proposed as dissolution inhibitors for chemically amplified resists can be used.

As the strong component (C), for example, a phenol derivative having a mass average molecular weight of 200 to 1000 and having 1 to 6 substituted or unsubstituted benzene nuclei is preferable.

Specific examples thereof include compounds represented by the following general formula (C 1) or (C 2).

[0117] [Chemical 25]

[R is an acid dissociable, dissolution inhibiting group. ]

[0118] [Chemical 26]

[R

C is an acid dissociable, dissolution inhibiting group. ]

[0119] The acid dissociable, dissolution inhibiting group R has been known so far in chemically amplified positive resists.

C

You can choose any power.

Specifically, tertiary alkyloxycarbo ol groups such as tert butyloxy carbo ol group, tert-amyloxy carbo ol group; tert butyloxy carboxymethyl group, tert butyl oxy Tertiary alkyloxycarbonyl alkyl groups such as xycarboxyl group; tertiary alkyl groups such as tert butyl group and tert amyl group; cyclic ether groups such as tetrahydrobiranyl group and tetrahydrofuranyl group; ethoxyethyl group , Metoki Preferred examples include alkoxyalkyl groups such as a cypropyl group.

Among them, tert-butyloxycarbol group, tert-butyloxycarboromethyl group, tert-butyl group, tetrahydrobiral group, ethoxyethyl group, 1-methylcyclohexyl group and 1-ethylcyclohexyl group are more preferable. Better ,.

Component (C) is used in an amount of 0.5 to 20 parts by mass per 100 parts by mass of component (A).

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

Any organic solvent can be used as long as it can dissolve each component to be used to form a uniform solution, and it can be arbitrarily selected from conventionally known solvents for chemically amplified resists.

For example, γ-latatones such as butyrolatatatone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, ethylene glycolol monoacetate, diethylene glycol, diethylene glycololmonomonoacetate , Propylene glycol, propylene glycol monoacetate, dipropylene glycol, or dipropylene glycol monoacetate, or polyhydric alcohols such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and their derivatives ; Cyclic ethers such as dioxane; Methyl lactate, Ethyl lactate (EL), Methyl acetate, Ethyl acetate, Butyl acetate, Methyl pyruvate Pyruvate Echiru, methyl methoxypropionate, esters such Echiru ethoxy propionic acid, and the like.

These organic solvents may be used alone or as a mixed solvent of two or more kinds. A mixed solvent in which propylene glycol monomethyl ether acetate (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. I prefer to do that!

More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. In addition, as the organic solvent, a mixed solvent of at least one selected from the PGMEA and EL medium strength and γ-petit-mouthed rataton is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

The amount of the organic solvent used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. Generally, the solid content concentration of the resist composition is 2 to 20%. It is used so that it may become mass%, Preferably 5-15 mass%.

[0121] 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. In addition, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be appropriately added and contained.

[0122] As described above, the positive resist composition of the present invention has a standing wave (SW), that is, a phenomenon in which the size of the resist pattern increases or decreases due to a change in the resist film thickness, and a resist pattern with a constant film thickness. Thus, the phenomenon that the side wall of the pattern becomes wavy due to the influence of the reflected light can be reduced. Among them, a resist pattern with reduced SW can be formed in a thin film with remarkable SW, which is suitable for a thin film implantation process.

As one of the reasons that a strong effect can be obtained, in the present invention, by using a resin (A1) having a structural unit having a functional group (SO 2) that is absorbable to exposure light,

2

It is considered that the reflected light was sufficiently absorbed and the influence of the reflected light could be suppressed.

SW is caused by the influence of the reflected light of the substrate power of exposure light.

As described above, in the past, in order to prevent this SW, a dye that absorbs reflected light from the substrate has been blended. However, the dye has insufficient absorption of the reflected light with the strength of the substrate and needs to be added in a large amount.

On the other hand, the dye has an inhibitory effect on dissolution in an alkaline developer, and if it is added in a large amount, problems such as scum generation occur, so there is a limit to the amount of dye added.

In addition, the transmittance of the alkaline developer is lowered due to the inhibition of the dissolution of the dye in the alkaline developer. For this reason, the generation efficiency of the acid having the component (B) is deteriorated and the dissociation property of the acid dissociable, dissolution inhibiting group is lowered, so that it is presumed that the resist pattern cannot be sufficiently formed. Yo Therefore, it is considered difficult to sufficiently reduce sw with dyes. In contrast, in the present invention, the functional group (SO) in the structural unit constituting rosin (A1).

2

), It is estimated that the reflected light from the substrate is sufficiently absorbed. Further, when the resin (A1) is used as a resist composition which does not have a problem of inhibition of dissolution in an alkaline developer such as a dye, a resist pattern is sufficiently formed. Therefore, it is considered that the positive resist yarn composition of the present invention can reduce SW.

In addition, since the dye is a low molecular weight compound, there is a problem that the glass transition temperature of the resin component is lowered by heating or sublimation immediately after heating, and the heat resistance of the resist film is lowered.

In the positive resist composition of the present invention, since the amount of dye added can be reduced or not added, problems such as sublimation by heating and a decrease in glass transition temperature can be solved.

[0123] SW is particularly prominent in the case of a thin film, and the positive resist composition of the present invention can form a resist pattern with reduced SW in a thin film. Therefore, SW is suitable for a thin film implantation process. Is.

[0124] Furthermore, the positive resist composition of the present invention is excellent in sensitivity and resolution. In addition, the depth of focus is large. Furthermore, it has excellent mask reality, and when the mask size is changed, a resist pattern faithful to the mask size can be reproduced. Since the resist pattern used in the thin film implantation process is used as a mask when implanting impurity ions, as described above, the positive pattern of the present invention can form a fine pattern with good reproducibility with only a small dimensional change. The resist composition is suitable for a thin film implantation process.

[0125] <Method for forming resist pattern>

The resist pattern forming method of the present invention comprises forming a resist film on a substrate using the positive resist composition, subjecting the resist film to a selective exposure process, and then developing a resist pattern. It is a method of forming.

As an example, a resist pattern can be formed as follows.

First, the positive resist composition of the present invention is applied to a spinner on a substrate such as a silicon wafer. After application, etc., a resist film is formed by applying a pre-beta for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C.

Next, the resist film is selectively exposed through a desired mask pattern using an exposure apparatus, and then subjected to a heat treatment (post-exposure) at a temperature of 80 to 150 ° C. 1 beta (PEB)) is applied for 40-120 seconds, preferably 60-90 seconds.

Then, an alkali developer solution, for example 1 to 10 wt ^_0/0 tetramethylammonium - lysis was developed with Umuhidorokishido (TMAH) aqueous solution, by performing a rinsing process, with a developer Contact and developing solution on the substrate The resist composition is washed, poured and dried to obtain a resist pattern.

The steps so far can be performed using a known method. It is preferable that the operating conditions and the like are appropriately set according to the composition and characteristics of the positive resist composition to be used.

If the film thickness of the resist film is 600 nm or less, it can be suitably used for a thin film implantation process, preferably 100 to 550 nm, more preferably 200 to 550 nm.

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

2, electron beam, X-ray, soft X-ray can be used.

The positive resist composition of the present invention is preferably used for a KrF excimer laser, an electron beam or EUV (extreme ultraviolet), and particularly suitable for a KrF excimer laser.

In some cases, a post-beta step may be included after the alkali development. Further, an organic or inorganic antireflection film may be provided between the substrate and the resist film or on the resist film.

[0128] The resist pattern thus obtained can reduce SW even if it is a thin film of 550 nm or less, and is suitable for a thin film implantation process.

Example

Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example are solid content except water, and show a mass part and the mass%, respectively. In Example 1 below, the resin (A) -1 represented by the following formula (1), and in Example 2, the resin represented by the following formula (2) (A) — 2 was used.

“EE” in the formula represents a 1 ethoxyethyl group.

[0131] [Chemical 27]

[0132] [Chemical 28]

[0133] Synthesis of Liquor (A) —1 and (A) —2>

[Synthesis of monomer (monomer providing structural unit (a3))]

Monomer that provides the structural unit (a3) contained in the coconut resin component (A) of the present invention: 4- (4-tetrahydroviranoxyphenylsulfoxy) phenol metatalylate was synthesized as follows. It was.

(1) Precursor: Synthesis of 4- (4-tetrahydroviranoxyphenylsulfoxy) phenol A 4-necked flask equipped with a nitrogen blowing tube, a reflux, a dropping funnel, and a thermometer was bis (4-hydroxyphenol). ) Sulfur 62g, 3,4 dihydro-1 2H pyran 21g and dioxane 3 70g were added and dissolved by stirring at about 20 ° C, and then a catalytic amount of P-toluenesulfonic acid monohydrate was added. Thereafter, stirring was continued at about 20 ° C. for 90 minutes. The obtained reaction solution was added dropwise to a large amount of 1.4% NaOH aqueous solution, toluene lOOg was added, and the mixture was stirred for 1 hour and allowed to stand. After confirming the separation, the upper layer (organic layer) was discarded, and while stirring the lower layer, 25 g of 36% hydrochloric acid was added to obtain a precipitate. The precipitate was filtered and washed with water to obtain a white solid (precursor).

(2) Synthesis of 4- (4-tetrahydrobiranoxyphenylsulfoxy) phenol metatalylate A precursor obtained in (1) above was placed in a four-necked flask equipped with a stirrer, thermometer and dropping funnel. The body, 4 g of triethylamine, and 290 g of acetone were added and dissolved by stirring. To this solution, 13 g of methacrylic acid chloride was slowly added dropwise at about 15 ° C, and stirring was continued at about 20 ° C for 1 hour. The obtained reaction solution was dropped into a large amount of water to obtain a precipitate. This precipitate was collected by filtration, washed with water, and dried to obtain 42 g of a white solid (4- (4-tetrahydroviranoxyphenylsulfoxy) phenol methacrylate).

(3) Identification of the white solid obtained in (2)

• Isotope hydrogen nuclear magnetic resonance ¹ H—NMR (CDC1) δ 1. 54— 2. 03 (6Η, m), 2.04 (3

Three

H, s), 3.60 (1H, m), 3.78 (1H, m), 5.49 (1H, t), 5.80 (1H, t), 6.35 (1 H, t) 7.13 (2H, d), 7.25 (2H, d), 7.85 (2H, d), 7.95 (2H, d).

[Synthesis of resin]

Resin (A)-1

(1) Synthesis of precursor polymer

A 4-necked flask equipped with a stirrer, nitrogen inlet tube, reflux condenser, thermometer, and dropping device was added with 4-g-acetyloxystyrene 0.5 g, styrene 0. lg, t-butyl attalylate 0. lg, 4 One (4-tetrahydrovinanoxyphenylsulfoxy) phenyl metatalylate (0.3 g) and 2-butanone (72 g) were added, the atmosphere was replaced with nitrogen, and the mixture was heated to 82 ° C. with stirring. While maintaining the above temperature, 4 -acetoxystyrene 46.2 g, styrene 8. lg, t-butyl atylate 10.0 g, 4- (4-tetrahydrovinanoxyphenylsulfoxy) phenyl metatalylate 31.3 g, Dimethyl 2, 2, monoazobis (2-methylpropionate) 6.0 g of 2-butanone dissolved in 72 g was dropped from a dropping device at a constant rate over 3 hours. After completion of the dropwise addition, stirring was continued for 5 hours while maintaining the above temperature.

After cooling to 20 ° C, the resulting reaction solution is stirred into a large amount of isopropyl alcohol. The solution was added dropwise with stirring to obtain a precipitate. The precipitate was separated by filtration to obtain a white solid precursor polymer.

(2) Synthesis of deprotected form

The precursor polymer obtained in (1) was placed in a four-necked flask equipped with a stirrer, a thermometer, and a dropping funnel, and 96 g of tetrahydrofuran was added thereto and dissolved by stirring at 20 ° C. To this solution, 36% hydrochloric acid (lg) was added dropwise and stirred at 20 ° C for 1 hour.

Thereafter, 36 g of 80% hydrazine monohydrate was added dropwise, followed by stirring at 20 ° C. for 1 hour. The obtained reaction solution was dropped into a large amount of water to obtain a precipitate. The precipitate was filtered, washed and dried to obtain 69 g of a white solid random copolymer.

(3) Identification of the white solid obtained in (2)

The mass average molecular weight (Mw) determined by gel permeation chromatography (GPC) in terms of polystyrene was 9,400, and the dispersity (MwZMn) was 1.61.

The copolymer composition ratio (molar ratio) determined by isotope carbon nuclear magnetic resonance ( ¹³ C-NMR) analysis is 4 -hydroxystyrene part: styrene part: t-butyl acrylate part: 4 The ratio of one-metal methacrylate was 53: 17: 11: 18.

Oil (A) — 2

(1) Synthesis of precursor polymer

A 4-necked flask equipped with a nitrogen blowing tube, a reflux condenser, a dropping funnel, and a thermometer was charged with 201 g of 2-butanone, 1.9 g of 4-acetoxystyrene, 4- (4-tetrahydrovinanoxyphenol-sulfoxy) -After adding 0.5 g of rumetatalylate and replacing with nitrogen, the temperature was raised to 82 ° C with stirring. While maintaining the above temperature, 187 g of 4-acetoxystyrene, 52 g of 4- (4-tetrahydrovinanoxyphenylsulfoxy) monophenyl methacrylate and dimethyl 2,2'-azobis (2-methylpropionate) ) A solution obtained by dissolving 13 g in 161 g of 2-butanone was added dropwise over 3 hours. After completion of dropping, stirring was continued for 5 hours while maintaining the temperature.

The obtained reaction solution was dropped into a large amount of isopropyl alcohol to obtain a precipitate. The precipitate was filtered and washed to obtain a white solid (precursor polymer).

(2) Synthesis of deprotected form

In the four-necked flask equipped with a stirrer, thermometer, and dropping funnel, A copolymer and 241 g of tetrahydrofuran were added and dissolved by stirring at 50 ° C. To this solution, 35 g of 36% hydrochloric acid was added dropwise, stirred at 50 ° C for 5 hours, and then cooled to 20 ° C to complete the reaction.

The obtained reaction solution was dropped into a large amount of water to obtain a precipitate. The precipitate was filtered, washed and dried to obtain a white solid (deprotected body).

(3) Synthesis of protector

In a four-necked flask equipped with a nitrogen blowing tube, a dropping funnel and a thermometer, 115 g of the white solid (polymer) obtained in (2) and 575 g of tetrahydrofuran were added and dissolved by stirring. Add 39 g of ethyl vinyl ether to the solution, stir at 20 ° C, add a catalytic amount of p-toluenesulfonic acid monohydrate, stir for 4 hours while maintaining the temperature, and add triethylamine to react. Stopped.

The obtained reaction solution was dropped into a large amount of water to obtain a precipitate. This precipitate was filtered off, washed and dried to obtain 146 g of a white solid (protector).

(4) Identification of white solid obtained in (3)

• Mass average molecular weight determined by gel permeation chromatography (GPC) in terms of polystyrene (

Mw) was 10,900, and the degree of dispersion (MwZMn) was 1.86.

The EE protection rate of the hydroxyl group of the 4-hydroxystyrene moiety determined by isotope hydrogen nuclear magnetic resonance (—NMR) analysis and the EE of the hydroxyl group of the 4- (4-hydroxyphenylsulfoxy) monophenol methacrylate moiety The total protection rate was 50%.

• The copolymer composition ratio (molar ratio) determined by isotope carbon nuclear magnetic resonance ( ¹³ C-NMR) analysis is 4

-Hydroxystyrene part: 4- (1-Ethoxyethoxy) Styrene part: 4 (4-hydroxyphenylsulfoxy) monophenolate part: 4- (4- (1-Ethoxyethoxy) phenol snoleoxy) -Lumetatalylate part = 40: 49: 3: 8.

A positive resist composition solution was prepared with the composition shown in Table 1.

In addition, the numerical value in [] shows a compounding quantity (mass part).

[0137] [Table 1]

[0138] In the composition shown in Table 1, components (A), (B), and (C) other than (A) -l and (A) -2

, (D) component, (E) component, organic solvent (S), additive AD used the following.

[0139] Component (A)

(A) 3: Hydroxystyrene Z Styrene Ztert Butyl acrylate (Molar ratio) = 7θΖΐ 5/15 (Mw = 12000, Mw / Mn = 2.1)

(A) -4: poly榭脂protecting the 39 mole ^_0/0 of the total hydroxyl groups of the (p-hydroxystyrene) in 1 Etokishechiru group (Mw = 8000, Mw / Mn = 2.0)

(A) -5: Poly 39 moles of all hydroxyl groups of (p-hydroxystyrene) ^_0/0 The resin protected with tert Butokishikaru Boniru group (Mw = 8000, Mw / Mn = l.1)

[0140] Component (B)

(B) -l:

[Chemical 29]

(B) — 2: Bis (tert-butylphenol-trifluoromethanesulfonate)

(B) — 3: Bis-O— (n-butylsulfonyl) a-dimethyldarioxime

(B) —4: Bis (cyclohexylsulfol) diazomethane

(B) — 5: Bis (tert-butylsulfonyl) diazomethane

(C) component

(C) 1:

[Chemical 30]

(C) -2:

[Chemical 31]

CH ₃ CH3 CH3 CH3

(R is -CH ₂ COO-tert-butyl group)

[0142] Component (D)

(D) — 1: Triethanolamine

(D) — 2: Triisopropanolamine

[0143] Component (E)

(E) — 1: Maleic acid

(E) -2: Salicylic acid

[0144] Additives AD

AD1: Dye Benzophenone

AD2: Dye

[Chemical 32]

AD3: Surfactant XR-104 (trade name, manufactured by Dainippon Ink & Chemicals, Inc.)

[0145] Organic solvent (S)

(S1): PGMEAZEL = 6Z4 (mass ratio)

[0146] <Evaluation>

A resist pattern was formed using the positive resist composition solution obtained above, and standing wave (SW) evaluation was performed as follows.

[0147] (1) SW evaluation in a resist pattern with a constant film thickness 1

(Example Comparative Example 1, Comparative Example 3)

The positive resist composition solution obtained in Example 1, Comparative Example 1, and Comparative Example 3 was uniformly applied on an 8-inch silicon wafer using a spinner, and 100 on a hot plate. C. Pre-beta for 60 seconds and drying to form a 250 nm thick resist film.

Next, selective exposure was performed through a binary mask using a KrF exposure apparatus (wavelength 248 nm) NSR-S203B (manufactured by Nikon, NA (numerical aperture) = 0.68, σ = 0.75).

Then, a PEB treatment was conducted under conditions of 110 ° C, 60 seconds, further 23 ° C at 2.38 mass ^_0/0 tetra Mechiruanmo - 60 seconds and puddle developed with Umuhidorokishido solution, then 30 seconds with pure water water Rinse and shake-dry.

Further, it was heated at 110 ° C. for 60 seconds and dried to form a 220 nm line-and-space (1: 1 and 1:10) resist pattern (hereinafter referred to as LZS pattern).

[0148] (Example 2, Comparative Example 2, Comparative Example 4)

The positive resist composition solution obtained in Example 2, Comparative Example 2, and Comparative Example 4 was uniformly applied on an 8-inch silicon wafer using a spinner, and 100 on a hot plate. C, pre-beta for 90 seconds and drying to form a resist film with a film thickness of 515 nm.

Then, PEB treatment was performed at 110 ° C for 90 seconds, followed by paddle development for 60 seconds with 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C, then pure water for 60 seconds. The sample was rinsed with water and shaken and dried.

Further, it was heated at 100 ° C. for 60 seconds and dried to form a 220 nm line-and-space (1: 1 and 1:10) resist pattern (hereinafter referred to as LZS pattern).

[0149] (SW evaluation 1)

The obtained resist pattern was visually evaluated according to the following criteria.

Table 2 shows the evaluation results.

O (Good): The standing wave was suppressed!

△ (Fair): A standing wave occurred slightly! /

X (Bad): A standing wave occurred!

[0150] [Table 2]

[0151] (2) SW evaluation in resist pattern when film thickness is changed 2

Example Using the positive resist composition solutions obtained in Comparative Example 1 and Comparative Example 3, resist films having film thicknesses of 175 nm, 190 nm, 210 nm, 230 nm, 240 nm, 250 nm, and 280 nm were formed, respectively, and the exposure amount was constant. Below, an LZS pattern (1: 1) targeting 220 nm is formed, and the line width (pattern dimension (hereinafter referred to as CD)) of the formed resist pattern is measured.

[0152] (SW evaluation 2)

For the obtained CD, the difference between the largest CD and the smallest CD was determined as SW (nm). The obtained SW is shown in Table 3, and the obtained pattern dimension behavior (graph) is shown in Figs. FIG. 1 is a diagram showing pattern dimension behavior with respect to changes in resist film thickness in Example 1, and FIG. 2 is a diagram showing pattern dimension behavior with respect to changes in resist film thickness in Comparative Example 1.

[0153] [Table 3] SW (nm)

Example 1 1 30

Comparative Example 1 143

Comparative Example 3

As is clear from the results in Table 2, in Examples 1 and 2, standing waves were suppressed.

In addition, from Table 3, it was confirmed that for SW, Example 1 had a smaller dimensional change with respect to film thickness change where SW was smaller than Comparative Example 1. In Comparative Example 3 to which no dye was added, the SW was remarkably large as the evaluation at the same coordinate could not be performed.

As described above, according to the present invention, it was confirmed that a positive resist composition and a resist pattern forming method capable of reducing the standing wave of the resist pattern can be provided.

Industrial applicability

The present invention can provide a positive resist composition and a resist pattern forming method that can reduce the standing wave of the resist pattern.

Claims

What is claimed is: A positive resist containing a resin component (A) having an acid dissociable, dissolution inhibiting group and increasing alkali solubility by the action of an acid, and an acid generator component (B) that generates an acid upon exposure to light In the composition, the resin component (A) is a structural unit (al) in which hydroxystyrene power is also induced, a structural unit (a2) having an acid dissociable, dissolution inhibiting group, and the following general formula (a3-1) )

[Chemical 1]

(a3-1)

r—— S0 ₂ — Ar— OR ¹

A positive resist composition comprising a resin (A1) having a structural unit (a3) represented by:

The structural unit (al) is represented by the following general formula (al— 1)

[Chemical 2]

[Wherein R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R represents a lower alkyl group having 1 to 5 carbon atoms; p represents an integer of 1 to 3; q represents 0 or Represents an integer from 1 to 2. ]

The positive resist composition according to claim 1, comprising a structural unit (al l) represented by: [3] The structural unit (a2) is represented by the following general formula (a2-1)

[Chemical 3]

The positive resist composition according to claim 1, comprising a structural unit (a21) represented by:

R ³ in the general formula (a2-1) represents a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl group, a chain or cyclic tertiary alkyl group, and the following general formula (I)

[Chemical 4]

[Wherein, X represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or a lower alkyl group; R ⁵ represents a hydrogen atom or a lower alkyl group, or X and R ⁵ each independently represent 1 carbon atom. An alkylene group of ˜5, which may be bonded to the end of X and the end of R ⁵ ; R ⁶ represents a hydrogen atom or a lower alkyl group. ]

The positive resist yarn composition according to claim 3, which is at least one acid dissociable, dissolution inhibiting group selected.

[5] The structural unit (a2) is represented by the following general formula (a2-2)

[Chemical 5]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R ² represents a lower alkyl group having 1 to 5 carbon atoms; p represents an integer of 1 to 3; Or represents an integer of 1 to 2; R ⁴ represents an acid dissociable, dissolution inhibiting group. ]

The positive resist composition according to claim 1, comprising a structural unit (a22) represented by:

R ⁴ in the general formula (a2-2) is a chain tertiary alkoxycarbonyl group, a chain tertiary alkoxycarbonylalkyl group, a chain or cyclic tertiary alkyl group, and the following general formula (I)

[Chemical 6]

R ⁶

—— C— 0— X

R ⁶ (to)

6. The positive resist yarn composition according to claim 5, which is at least one acid dissociable, dissolution inhibiting group selected.

7. The positive resist composition according to claim 1, wherein the resin (A1) further has a structural unit (a4) that induces styrene power.

[8] The structural unit (a4) is represented by the following general formula (a4-1)

[Chemical 7]

[Wherein, R represents a hydrogen atom, an alkyl group, a fluorine atom or a fluorinated alkyl group; R represents a lower alkyl group having 1 to 5 carbon atoms; q represents 0 or an integer of 1 to 2; The positive resist composition according to claim 7, comprising a structural unit (a41) represented by:

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

[10] After a resist film is formed on the substrate using the positive resist composition according to any one of claims 1 to 9, and the resist film is selectively exposed, A resist pattern forming method in which a development pattern is applied to form a resist pattern.