WO2008047623A1

WO2008047623A1 - Chemically amplified positive resist composition for thermal lithography and method for formation of resist pattern

Info

Publication number: WO2008047623A1
Application number: PCT/JP2007/069617
Authority: WO
Inventors: Sanae Furuya; Hideo Hada
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-10-18
Filing date: 2007-10-05
Publication date: 2008-04-24
Also published as: JP2008102277A; TW200832067A

Abstract

Disclosed is a chemically amplified positive resist composition for thermal lithography, which is intended to be used for the formation of a resist film for use in thermal lithography. A resist film formed by using the chemically amplified positive resist composition has an absorbance of 0.08 or greater per 100 nm in thickness as measured at a wavelength of an exposure light source used in the thermal lithography.

Description

Specification

Chemically amplified positive resist composition for thermal lithography and method for forming resist pattern

Technical field

The present invention relates to a chemically amplified positive resist composition for thermal lithography and a resist pattern forming method using the chemically amplified positive resist composition for thermal lithography.

This application (October 2006 18-18 曰曰曰曰特特特 2006 — — — — — — — — — — — — —-— — — — 2006 し 2006 しししを優先

Background art

[0002] Lithography technology is frequently used for the production of fine structures in various electronic devices such as semiconductor devices and liquid crystal devices.

In the lithography technology, a photosensitive organic material called a photoresist has been conventionally used. As photoresists, those whose solubility (alkali solubility) in an alkali developer is generally changed by irradiation (exposure) of radiation, for example, short-wavelength light such as vacuum ultraviolet rays, electron beam and laser radiation, and so on. It is used. The strength of such a photoresist changes its alkali solubility due to the partial decomposition of the structure or the formation of crosslinks upon exposure. As a result, a difference in alkali solubility occurs between the exposed portion and the unexposed portion, thereby making it possible to form a resist pattern. That is, when selective exposure is performed on the photoresist, the alkali solubility of the photoresist partially changes, and the photoresist is divided into a portion having a high alkali solubility and a portion having a low alkali solubility. It has a pattern consisting of When this photoresist is developed with an alkali, a portion having high alkali solubility is dissolved and removed, thereby forming a resist pattern.

There are two types of photoresist: a positive type in which the alkali solubility in the exposed area is increased, and a negative type in which the alkali solubility in the exposed area is decreased.

As one of the photoresists with high sensitivity to short wavelength exposure light source, photoacid generator (PAG) that generates acid by the action of radiation and alkali solubility by the action of the acid. Chemically amplified resist compositions containing a changing base material component are known (see, for example, Patent Documents !! to 2).

[0003] In the data writing process of optical ROM (Read Only Memory) discs, in the near future, in order to realize ultra-high density recording, lithography technology that realizes pits of at least lOOnm or less is desired!

As described above, the development using a method using a light source with a shorter wavelength or a method using an electron beam has been developed so far!

However, as the wavelength of the light source used for exposure becomes shorter, various difficult problems are caused not only by the light source but also by optical factors. For example, exposure machines tend to be more expensive and larger as the wavelength of the light source becomes shorter. Also, when using an electron beam, high voltage conditions, a vacuum chamber, etc. are required to generate an electron beam. Necessary, and as a result, large force and equipment are required. These problems increase the manufacturing cost of products such as optical CD-ROM discs.

One technique that has been recently developed is thermal lithography. In this method, light is not used directly, but heat distribution generated by light is used. According to thermal lithography, it is possible to perform fine drawing smaller than the spot diameter of light, and it is possible to form a fine pattern and achieve high speed and low cost! /.

As a thermal lithography method that has already been reported, there is a method using an inorganic material whose properties change suddenly when the temperature exceeds a certain level. For example, Non-Patent Document 1 discloses a laminate in which a ZnS-SiO layer, a TbFeCo layer, and a ZnS-SiO layer are laminated in this order on a substrate.

twenty two

A method of using is described. This method is a thermal lithography that uses volume change due to heat. In such a method, the TbFeCo layer absorbs laser light and generates heat, and when its temperature exceeds 200 ° C, its volume begins to increase. As a result, the pattern is formed by increasing the film thickness of the portion irradiated with the laser beam.

In addition, a method using platinum oxide as the inorganic material has been reported (for example, see Non-Patent Document 2). This method uses the property that platinum oxide evaporates explosively when the temperature exceeds a certain temperature. The platinum oxide applied to the substrate surface is heated by shining a blue laser beam on it and is necessary for processing. I try to remove the part. This way For example, it is said that fine pattern formation of lOOnm or less can be realized with blue laser light (wavelength 405nm).

Further, for example, Non-Patent Document 3 discloses a Ge Sb Te layer on a polycarbonate substrate,

2 2 5

There is a method using a laminate in which a ZnS-SiO layer and a photoresist film are laminated in this order.

2

Are listed. In this method, first, when a red laser is irradiated from the lower side of the substrate, the laser light is absorbed by Ge Sb Te, and Ge Sb Te generates heat. This heat, on top of that

2 2 5 2 2 5

It is transferred to the resist film (negative) of the layer, and the resist film changes to alkali insoluble by the action of the heat. Therefore, a resist pattern is formed by alkali developing this. Patent Document 1: Japanese Patent No. 2881969

Patent Document 2: Japanese Patent Application Laid-Open No. 2003_241385

Non-Patent Document l: Jpn. J. Appl. Phys. Vol. 43, No. 8B (2004) pp. L1045-L104 7

Non-Patent Document 2: The 53rd Joint Conference on Applied Physics, Preliminary Proceedings, pp. 1051 (Spring 2006 6), 22a-D-9

Non-Patent Document 3: Jpn. J. Appl. Phys. Vol. 41, No. 9A / B (2002) pp. L1022-L 1024

Disclosure of the invention

Problems to be solved by the invention

All the proposed thermal lithography techniques use inorganic materials to absorb light and convert the energy into heat. However, these inorganic materials are often expensive and have problems such as poor processability such as substrate etching after the formation of the resist pattern.

One way to solve the above problem is to perform thermal lithography using only organic materials. However, until now, only organic materials without using inorganic materials have been used.

V, the technology to do thermal lithography has been proposed!

The present invention has been made in view of the above circumstances, and is a chemically amplified positive resist composition for thermal lithography capable of forming a resist pattern by thermal lithography, and the chemically amplified positive resist for thermal lithography. Resist pattern form using the composition The purpose is to provide a method for the creation.

Means for solving the problem

[0006] As a result of intensive studies, the present inventors have developed a chemically amplified positive resist composition in which the absorbance of the formed resist film with light having a wavelength of a light source used for exposure is a predetermined value or more. The inventors have found that the above problems can be solved, and have completed the present invention.

That is, a first aspect of the present invention is a chemically amplified positive resist composition for thermal lithography for forming a resist film used in thermal lithography, the chemical amplified positive resist composition for thermal lithography. A chemically amplified positive resist for thermal lithography, in which the resist film formed using the mold resist composition has an absorbance of 0.08 or more per 10 Onm of film thickness at the wavelength of the exposure light source used in the thermal lithography. Composition.

The second aspect of the present invention is a step of forming a resist film on a support using the chemically amplified positive resist composition for thermal lithography of the first aspect. The resist pattern forming method includes a step of performing selective exposure using light having a wavelength of 0.08 or more per 1 lOOnm, and a step of developing the resist film to form a resist pattern.

A third aspect of the present invention is a chemically amplified positive resist composition for thermal lithography for forming a resist film used in thermal lithography.

A base component (A) whose alkali solubility is increased by the action of an acid; an acid generator component (B) which generates an acid by the action of heat; and a wavelength of an exposure light source used in the thermal lithography of 350 nm or more. Containing a dye (C) that absorbs light,

The compounding amount of the dye (C) is a chemically amplified positive resist composition for thermal lithography that is 8 to 65 mass% with respect to the component (A).

According to a fourth aspect of the present invention, there is provided a step of forming a resist film on a support using the chemically amplified positive resist composition for thermal lithography according to the third aspect. The resist film has a wavelength of 350 nm or more. A resist pattern forming method including a step of performing selective exposure using the above light and a step of developing the resist film to form a resist pattern.

[0007] In the present specification and claims, "exposure" includes general irradiation of radiation. Let it be a concept.

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

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

The “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.

“Structural unit” means a monomer unit (monomer unit) constituting a resin (polymer).

Yes

The invention's effect

[0008] According to the present invention, a chemically amplified positive resist composition for thermal lithography capable of forming a resist pattern by thermal lithography, and a resist pattern forming method using the chemically amplified positive resist composition for thermal lithography are provided. Can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] «Chemically amplified positive resist composition for thermal lithography»

The chemical amplification type positive resist composition for thermal lithography of the present invention is a resist film force formed using the chemical amplification type positive resist composition for thermal lithography. An exposure light source used in the thermal lithography It is necessary to have an absorbance of 0.08 or more per lOOnm film thickness at the wavelength. Thus, when the absorbance is 0.08 or more, a resist pattern can be formed by thermal lithography. That is, a chemically amplified positive resist composition usually comprises a base material component (A) whose alkali solubility is increased by the action of an acid and an acid generator component (B) that generates an acid by the action of heat. Contains as an essential ingredient. The acid generator component (B) used in the chemically amplified positive resist composition usually generates an acid even when heated to a certain temperature or higher, as in the case of exposure. If the absorbance of the resist film made of the chemically amplified positive resist composition is 0.08 or more, when the resist film is exposed by thermal lithography, the acid generator component ( B) generates heat at a temperature sufficient to generate an acid. Therefore, when the resist film is selectively exposed in the formation of the resist pattern, an acid is generated from the acid generator component (B) in the exposed portion, and the base component (A) is formed by the action of the acid. While the potash solubility is increased, the unexposed portion remains insoluble in alkali and does not change. Therefore, a resist pattern can be formed by developing the resist film with alkali. The upper limit of the absorbance is preferably not more than 0.5, more preferably not more than 0.45 per film thickness lOOnm, considering the influence of thermal interference that is not particularly limited and the lithospheric characteristics such as sensitivity. Most preferred is 4 or less.

The lower limit of the absorbance is preferably 0.08 or more per film thickness lOOnm, more preferably 0.10 or more, and most preferably 0.20 or more.

[0010] The absorbance can be adjusted by adjusting the type and amount of components to be blended in the chemically amplified positive resist composition. For example, the absorbance can be adjusted by adding a dye (C) that absorbs light having a wavelength of an exposure light source, which will be described later. The higher the content of the dye (C), the more the light of the dye (C). The higher the absorbency, the greater the absorbance. In addition, the base material component (A) described later absorbs light having the wavelength of an exposure light source used in thermal lithography as in the case of the dye (C) (hereinafter simply referred to as “having light absorption”). In the case of an M compound, the absorbance can also be adjusted by adjusting the type and amount of the base component (A).

In the present specification and claims, the absorbance is determined by forming a resist film on a quartz substrate using the chemically amplified positive resist composition for thermal lithography, and exposing the resist film. It is determined by measuring the absorbance at the wavelength of the light source and calculating the absorbance per lOOnm of the resist film from the value and the thickness of the resist film.

The resist film can be formed by applying an organic solvent solution of the chemical amplification type positive resist composition for thermal lithography on a quartz substrate by spin coating, and performing beta. The beta temperature may be appropriately set according to the chemically amplified positive resist composition to be used without any particular limitation.

The absorbance of the resist film can be measured using, for example, a commercially available spectrophotometer.

[0012] As a preferred embodiment of the chemically amplified positive resist composition for thermal lithography of the present invention (hereinafter sometimes simply referred to as the positive resist composition of the present invention), alkali solubility is increased by the action of an acid. Base material component (A) (hereinafter referred to as component (A)) and the action of heat An acid generator component that generates an acid (B) (hereinafter referred to as component (B)) and a dye (C) that absorbs light of the wavelength of the exposure light source (hereinafter referred to as component (C)) The positive resist composition has a strength S. When forming a resist pattern, when a resist film formed using a positive resist composition is selectively exposed, the component (C) mainly absorbs the light and generates heat. This heat acts on the component (B) to generate an acid, and this acid acts on the component (A) to increase its alkali solubility.

[0013] <Component (A)>

The component (A) is not particularly limited, and any one of the strengths proposed so far as a base component for a chemically amplified positive resist composition can be selected and used. That power S. As the substrate component, one having an acid dissociable, dissolution inhibiting group is generally used. The base material component is insoluble in alkali before exposure, and when an acid is generated from component (B) after exposure, the acid dissociable, dissolution inhibiting group is dissociated by the action of the acid, and changes to alkali soluble. To do.

Here, the “base material component” is an organic compound having a film forming ability, and preferably an organic compound having a molecular weight of S500 or more is used. When the organic compound has a molecular weight of 500 or more, the film-forming ability is improved and a nano-level pattern is easily formed.

The organic compound having a molecular weight of 500 or more is classified into a low molecular weight organic compound (hereinafter referred to as a low molecular compound) having a molecular weight of 500 or more and 2000 or less, and a high molecular weight resin (polymer) having a molecular weight of 2000 or more. Broadly divided. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer), the “molecular weight” is the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation matrix). Hereinafter, the term “resin” simply refers to a resin having a molecular weight of more than 2000.

The component (A) may be a low molecular compound whose alkali solubility is increased by the action of an acid, or a mixture of these, which may be a resin whose alkali solubility is increased by the action of an acid. May be.

[0015] The component (A) preferably has a hydrophilic group in addition to the acid dissociable, dissolution inhibiting group! /. By having the hydrophilic group, the hydrophilicity of the entire component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. The hydrophilic group is selected from the group consisting of a hydroxyl group, a carboxy group, a carbonyl group (—c (o) —), an ester group (ester bond; —C (〇) —〇—), an amino group, and an amide group. One or more selected from the above are preferred. Among these, a hydroxyl group (particularly an alcoholic hydroxyl group or a phenolic hydroxyl group), a carboxy group, and an ester group are more preferable. Among them, carboxy group, alcoholic hydroxyl group, phenolic hydroxyl group power is small, and line edge roughness (pattern side wall irregularities) is small at the nano level! The hydrophilic group may also serve as an acid dissociable, dissolution inhibiting group.

[0016] As the component (A) of the positive resist composition of the present invention, the following component (A-1) and / or component (A-2) are preferred!

• Component (A-1): a resin having a structural unit having an acid dissociable, dissolution inhibiting group.

• Component (A-2): A low molecular compound having an acid dissociable, dissolution inhibiting group.

Hereinafter, preferred and / or embodiments of the component (A-1) and the component (A-2) will be described more specifically.

[0017] [(8-1) component]

The component (A-1) is a resin having a structural unit having an acid dissociable, dissolution inhibiting group. The proportion of the structural unit having the acid dissociable, dissolution inhibiting group in the component (A-1) is 20 to 80 mol% with respect to the total amount of all the structural units constituting the component (A-1). it is good preferred, preferably from 20 to 70 Monore ^_0/0 Ca, 30-60 Monore ^_0/0 mosquitoes more preferred.

[0018] The component (A-1) preferably further has a structural unit having a hydrophilic group in addition to the structural unit having an acid dissociable, dissolution inhibiting group. As the hydrophilic group, those similar to the above are preferably used.

Preferably, the structural unit having a hydrophilic group is a structural unit having a carboxy group, an alcoholic hydroxyl group or a phenolic hydroxyl group, more preferably an acrylic acid, a metathallic acid or an alcoholic hydroxyl group (α — Lower alkyl) acrylate ester, hydroxystyrene power is a structural unit derived.

The proportion of the structural unit having a hydrophilic group in the component (Α-1) is preferably 20 to 80 mol% with respect to the total amount of all the structural units constituting the component (Α-1). more preferably Mashigu 20-70 Monore ^_0/0 Ca, 20-60 Monore ^_0/0 mosquitoes more preferred.

[0019] (Α-1) More specifically, as a component, a nopolac resin having an acid dissociable, dissolution inhibiting group , Hydroxystyrene resins, (α lower alkyl) acrylate resins, copolymer resins containing structural units derived from hydroxy styrene and (α lower alkyl) acrylate forces derived structural units, etc. are preferably used. It is done.

In this specification, “(α lower alkyl) acrylic acid” means acrylic acid (CH

2

= CH—COOH) and / or α lower alkyl acrylic acid. a Lower alkyl acrylic acid refers to a hydrogen atom bonded to the carbon atom to which the carbonyl group in acrylic acid is bonded (the carbon atom at position a) substituted with the lower alkyl group.

“(Α-lower alkyl) acrylic acid ester” is an ester derivative of “(α-lower alkyl) acrylic acid”, and one of the acrylic acid ester and α-lower alkyl acrylic acid ester! / Indicates both.

“(Α lower alkyl) acrylate ester derived structural unit” is a structural unit formed by the cleavage of the ethylenic double bond of (α lower alkyl) acrylate ester. Sometimes referred to as (α-lower alkyl) attalylate structural unit. “(Α-Lower alkyl) acrylate” refers to one or both of acrylate and α-lower alkyl acrylate.

The “structural unit derived from hydroxystyrene” is a structural unit formed by the cleavage of the ethylenic double bond of hydroxystyrene or α-lower alkylhydroxystyrene, and is hereinafter sometimes referred to as a hydroxystyrene unit. “Α-lower alkylhydroxystyrene” indicates that the lower alkyl group is bonded to the carbon atom to which the phenyl group is bonded.

In the “structural unit derived from α-lower alkyl acrylate” and “structural unit derived from α-lower alkylhydroxystyrene”! The group is an alkyl group having 1 to 5 carbon atoms, and a straight chain or branched chain alkyl group is preferred, methyl group, ethyl group, propyl group, isopropyl group, n butyl group, isobutyl group, tert butyl group Pentyl group, isopentyl group, neopentyl group, and the like. Industrially, a methyl group is preferable.

The resin component suitable as the component (A-1) is not particularly limited. For example, a group having a phenolic hydroxyl group such as the following structural unit (al) and at least one acid dissociable, dissolution inhibiting group selected from the group consisting of the following structural unit (a2) and the following structural unit (a3) And a resin component (hereinafter also referred to as component (A-11)) having an insoluble unit such as (a4) used as necessary.

The component (A-11) is cleaved in the structural unit (a2) and / or the structural unit (a3) by the action of the acid generated from the acid generator upon exposure. Therefore, the alkali solubility of the resin that was initially insoluble in the alkali developer is increased. As a result, the force S can be used to form a chemically amplified positive pattern by exposure and development.

[0021] · · Unit ( _a l)

The structural unit (al) is a unit having a phenolic hydroxyl group, and is preferably a unit derived from a hydroxystyrene force represented by the following general formula (Γ).

[0022] [Chemical 1]

(In the formula, R represents a hydrogen atom or a lower alkyl group.)

[0023] R is a hydrogen atom or a lower alkyl group. The lower alkyl group is the same as the lower alkyl group bonded to the α-position and particularly preferably a hydrogen atom or a methyl group. The description of R is the same below.

The bonding position of ΟΗ to the benzene ring is not particularly limited, but the 4 position (para position) described in the formula is preferred!

The structural unit (al) is, (A- 11) component 40 to 80 mol% in, preferably is preferably contained 50 to 75 mole ^_0/0. By setting it to 40 mol% or more, solubility in an alkali developer can be improved, and an effect of improving the pattern shape can be obtained. 80 mol% or less By doing so, it is possible to balance with other structural units.

[0024] · · Unit ( _a 2)

The structural unit (a2) is a structural unit having an acid dissociable, dissolution inhibiting group, and has the following general formula (

(ΙΓ).

[0025] [Chemical 2]

-ill ')

(In the formula, R represents a hydrogen atom or a lower alkyl group, and X represents an acid dissociable, dissolution inhibiting group.)

[0026] The acid dissociable, dissolution inhibiting group X is an alkyl group having a tertiary carbon atom, and the tertiary carbon atom of the tertiary alkyl group is bonded to the ester group [C (O) O]. / !, a releasable dissolution inhibiting group, a cyclic acetal group such as a tetrahydrobiranyl group and a tetrahydrofuranyl group.

Such an acid dissociable, dissolution inhibiting group X is used in, for example, a chemically amplified positive resist composition! /, And other than the above can be arbitrarily used. .

As the structural unit (a2), for example, those represented by the following general formula (ΠΓ) are preferred.

[0028] [Chemical 3]

… (1 I Ϊ ^J ) In the formula, R is a hydrogen atom or a lower alkyl group, and R, R, and R are each independently And an alkyl group (which may be linear or branched, preferably a lower alkyl group having 1 to 5 carbon atoms). Or, among R ^U , R ¹² and R ¹³ , R ¹¹ is a lower alkyl group, and R ¹² and R ¹³ may be bonded to form a monocyclic or polycyclic aliphatic cyclic group. . The aliphatic cyclic group preferably has 5 to 12 carbon atoms.

Here, “aliphatic” means that the group or compound does not have aromaticity, and “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity. Means a group.

When R ^u , R ¹² , and R ¹³ do not have an aliphatic cyclic group, for example, those in which R ^U , R ¹² , and R ¹³ are all methyl groups are preferred.

When any of R ^u , R ¹² , and R ¹³ has an aliphatic cyclic group, when the aliphatic cyclic group is a monocyclic aliphatic cyclic group, the structural unit (a2) is, for example, Those having a cyclopentyl group or a cyclohexyl group are preferred.

When the aliphatic cyclic group is a polycyclic alicyclic group, it is preferable as the structural unit (a2)! /, And examples thereof include those represented by the following general formula (IV ′) Can do.

[0030] [Chemical 4]

-(IV)

[Wherein, R represents a hydrogen atom or a lower alkyl group, and R ¹⁴ represents an alkyl group (which may be linear or branched, preferably a lower alkyl group having 1 to 5 carbon atoms). ]

[0031] Further, those having an acid dissociable, dissolution inhibiting group containing a polycyclic aliphatic cyclic group are also preferably those represented by the following general formula (V ').

[0032] [Chemical 5]

… (V "

[Wherein, R represents a hydrogen atom or a lower alkyl group, and R 1 and R 2 each independently represents an alkyl group (either a straight chain or a branched chain. Preferably, it is a lower alkyl group having 1 to 5 carbon atoms. ). "

[0033] structural unit (a2), (A- 1 1) in the component, 5-50 Monore ^_0/0, preferably 10-40 Monore ^_0/0, more preferably in the range of 10 to 35 mol% Preferably it is present.

[0034] · · Structural unit (a3)

The structural unit (a3) is a structural unit having an acid dissociable, dissolution inhibiting group, and is represented by the following general formula (VI ′).

[0035] [Chemical 6]

(In the formula, R is a hydrogen atom or a lower alkyl group, and X, an acid dissociable, dissolution inhibiting group.)

The acid dissociable, dissolution inhibiting group X ′ is a tertiary alkyloxycarbonyl group such as tert-butyloxycarbonyl group or tert-amyloxycarbonyl group; tert-butyloxy group sulfonylmethyl group, tert-butyloxycarbonyl group Tertiary alkyl such as til group An oxycarbonylalkyl group; a tertiary alkyl group such as a tert-butyl group or a tert-amyl group; a cyclic acetal group such as a tetrahydrobiranyl group or a tetrahydrofuranyl group; an alkoxyalkyl group such as an ethoxychetyl group or a methoxypropyl group; is there.

Of these, a tert butyloxycarbonyl group, a tert butyloxycarbonylmethyl group, a tert butyl group, a tetrahydrobiranyl group, and an ethoxyethyl group are preferable.

As the acid dissociable, dissolution inhibiting group X ′, any of those used in, for example, a chemically amplified positive resist composition other than the above can be arbitrarily used.

In the general formula (VI '), the bonding position of the group (-OX') that binds to the benzene ring! / Is not particularly limited! /, I prefer the position (para position)!

[0037] Configuration unit (a3), (A- 11) in the component, 5-50 Monore ^_0/0, preferably preferably 10 to 40 Monore ^_0/0, and et, a range of 10 to 35 mol% Is done.

[0038] · · Unit ( _a 4)

The structural unit (a4) is an alkali-insoluble unit and is represented by the following general formula (νΐΓ).

[0039] [Chemical 7]

(II *):

(In the formula, R represents a hydrogen atom or a lower alkyl group, R ⁴ represents an alkyl group, and η ′ represents 0 or an integer of 1 to 3.)

[0040] The alkyl group of R ⁴ may be either a straight chain or a branched chain, and preferably has a carbon number.

;! To 5 lower alkyl groups.

η ′ is preferably 0 or a force 0 indicating an integer of 1 to 3.

[0041] the structural unit (a4), (A- 11) in the component;! ~ 40 Monore ^_0/0, and preferably from 5 to 25 mole ^_0/0. By making it 1 mol% or more, the effect of shape improvement (especially improvement of film loss) becomes high. Ri can take by 40 mole ^_0/0 or less, the balance with the other structural units.

[0042] In the component (A-11), the structural unit (al), the structural unit (a2), and the structural unit

While at least one selected from the group consisting of (a3) is essential, (a4) may optionally be included. Further, a copolymer having all these units may be used, or a mixture of polymers having one or more of these units may be used. Or they may be combined.

Further, the component (A-11) can optionally contain other than the structural units (al) to (a4). The total proportion of the structural units (al) to (a4) is 80 mol% or more. , preferably 90 mol% or more (100 mol ^_0/0 and most preferably? /,) it is preferably a! /,.

[0043] In particular, "any force of the copolymer having the structural units (al) and (a3), one, or a mixture of two or more of the copolymers", or "the structural unit (al), An embodiment in which any one of the copolymers having (a2) and (a4) or a mixture of two or more of the copolymers is used or mixed with each other can provide an effect easily. Therefore, it is most preferable. Also preferred for improving heat resistance!

In particular, a mixture of polyhydroxystyrene protected with a tertiary alkyloxycarbonyl group and polyhydroxystyrene protected with a 1 alkoxyalkyl group is preferred. When such mixing is performed, the mixing ratio (mass ratio) of each polymer (polyhydroxystyrene protected with tertiary alkyloxycarbonyl group / 1 polyhydroxystyrene protected with alkoxyalkyl group) is, for example, 1/9 to 9 / 1, preferably 2/8 to 8/2, and more preferably 2/8 to 5/5.

[0044] In addition to the component (A-11), as a resin component suitable as the component (A-1), an (α-lower alkyl) attalyte is particularly preferable in that a pattern with lower etching resistance can be formed. A resin component comprising a ( _α lower alkyl) acrylate resin is more preferred, and a resin component comprising a (α lower alkyl) acrylate resin is more preferred.

In the (α lower alkyl) acrylate resin (hereinafter referred to as the (Α-12) component), the structural unit (a5) derived from the (α lower alkyl) acrylate ester containing an acid dissociable, dissolution inhibiting group. A resin having is preferred. α lower alkyl group (bonded to α position) The lower alkyl group) is the same as described above.

The acid dissociable, dissolution inhibiting group of the structural unit (a5) has an alkali dissolution inhibiting property that makes the entire resin component insoluble before exposure to alkali insolubility, and at the same time dissociates due to the action of an acid generated from the (B) component. , (A-12) is a group that changes the entire component to alkali-soluble.

[0045] As the acid dissociable, dissolution inhibiting group, for example, a resin for resist composition of ArF excimer laser can be selected and used as appropriate. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group of (α lower alkyl) acrylic acid, or a cyclic or chain alkoxyalkyl group is widely known.

Here, the “group that forms a tertiary alkyl ester” is a group that forms an ester by substituting the hydrogen atom of the carboxy group of acrylic acid. That is, the tertiary carbon atom of the chain or cyclic tertiary alkyl group is bonded to the terminal oxygen atom of the carbonyloxy group [C (O) -0-] of the acrylate ester! / The structure is shown. In this tertiary alkyl ester, when an acid acts, the bond is broken between the oxygen atom and the tertiary carbon atom.

The tertiary alkyl group is an alkyl group having a tertiary carbon atom. Examples of the group that forms a chain-like tertiary alkyl ester include a tert butyl group and a ter tamyl group.

Examples of the group that forms the cyclic tertiary alkyl ester include those exemplified in the “acid dissociable, dissolution inhibiting group containing an alicyclic group” described later.

[0046] The "cyclic or chain alkoxyalkyl group" forms an ester by substituting for a hydrogen atom of a carboxy group. That is, a structure is formed in which the alkoxyalkyl group is bonded to the terminal oxygen atom of the carbonyloxy group [C (O) —O—] of the acrylate ester. In such a structure, the bond between the oxygen atom and the alkoxyalkyl group is broken by the action of an acid.

Examples of such a cyclic or chain alkoxyalkyl group include 1-methoxymethyl group, 1 ethoxyethynole group, 1 isopropoxy chinenole, 1-cyclohexino leschichinole. Is mentioned.

[0047] As the structural unit (a5), a structural unit containing an acid dissociable, dissolution inhibiting group containing a cyclic group, particularly an aliphatic cyclic group, is preferred.

Here, “aliphatic” and “aliphatic cyclic group” are as defined above. The aliphatic cyclic group may be either monocyclic or polycyclic, and may be appropriately selected from among many proposed, for example, ArF resists. From the viewpoint of etching resistance, a polycyclic alicyclic group is preferred. The alicyclic group is preferably a hydrocarbon group, and particularly preferably a saturated hydrocarbon group (alicyclic group).

An example of a monocyclic alicyclic group is a group S in which one hydrogen atom is removed from a cycloalkane. Examples of the polycyclic alicyclic group include groups in which one hydrogen atom has been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like.

Specifically, examples of the monocyclic alicyclic group include force S such as a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic group include groups in which one hydrogen atom is removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Among these, adamantyl group obtained by removing one hydrogen atom from adamantane, norbornyl group obtained by removing one hydrogen atom from norbornane, tricyclodecanyl group obtained by removing one hydrogen atom from tricyclodecane, tetra The tetracyclododecanyl group, in which one hydrogen atom is removed from cyclododecane, is industrially preferred.

More specifically, the structural unit (a5) is preferably at least one selected from the following general formulas (Γ) to (ΠΓ).

Further, a unit derived from an (α lower alkyl) acrylate ester having a cyclic alkoxyalkyl group as described above at its ester part, specifically a 2-adamantoxymethyl group, 1-methyl Aliphatic polycyclic alkyloxy group which may have a substituent such as adamantoxymethyl group, 4-oxo-2-adamantoxymethyl group, 1-adamantoxychetyl group, 2-adamantoxychetyl group, etc. Alkyl (α lower alkyl) acrylate ester power It is preferably at least one selected from units derived. That's right.

[0049] [Chemical 8]

In i 3 (1,), R is a hydrogen atom or a lower alkyl group, and R ¹ is a lower alkyl group.

[0050] [Chemical 9]

[In the formula (II "), R is a hydrogen atom or a lower alkyl group, and R ² and IT are each independently a lower alkyl group.]

[0051] [Chemical 10]

[In the formula (ΠΓ), R is a hydrogen atom or a lower alkyl group, and R ⁴ is a tertiary alkyl group. "

In the formulas (Γ) to (III ″), the hydrogen atom or lower alkyl group for R is the same as described above for the hydrogen atom or lower alkyl group bonded to the _α- position of the attalinoleic acid ester. The lower alkyl group of R is an alkyl group having 1 to 5 carbon atoms, and a methyl group, an ethyl group, a propyl group, an isopropyl group, an η-butyl group, and a linear or branched alkyl group are preferred. , Isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. Methyl group is preferred industrially.

As the lower alkyl group for R ¹ , a linear or branched alkyl group having 1 to 5 carbon atoms is preferable. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. Group, pentyl group, isopentyl group, neopentyl group and the like. Of these, a methyl group and an ethyl group are preferred because they are easily available industrially.

The lower alkyl group for R ² and R ³ is preferably each independently a linear or branched alkyl group having carbon atoms of! In particular, it is industrially preferable that R ² and R ³ are both methyl groups. Specific examples include structural units derived from 2- (1-adamantyl) -2-propyl acrylate.

[0053] R ⁴ is preferably a chain-like tertiary alkyl group or a cyclic tertiary alkyl group, and preferably has 4 to 20 carbon atoms! /.

Examples of the chain-like tertiary alkyl group include a tert-butyl group and a tert-amyl group, and the tert-butyl group is industrially preferable. The tertiary alkyl group is an alkyl group having a tertiary carbon atom. The cyclic tertiary alkyl group is the same as that exemplified in the above-mentioned “acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group”, and includes a 2-methyl-2-adamantyl group, 2-ethi Examples thereof include a nore 2-adamantyl group, a 2- (1-adamantyl) -2-propyl group, a 1-ethylcyclohexyl group, a 1-ethylcyclopentyl group, a 1-methylcyclohexyl group, and a 1-methylcyclopentyl group.

The group COOR ⁴ may be bonded to the 3 or 4 position of the tetracyclododecanyl group shown in the formula, but the bonding position cannot be specified. Similarly, the carboxyl group residue of the attalylate constituent unit may be bonded to the position 8 or 9 shown in the formula.

[0054] The structural unit (a5) can be used alone or in combination of two or more.

(A- 12), the amount of the structural unit (a5) is, (A- 12) relative to the combined total of all structural units constituting the component that force S preferably from 20 to 60 mole ^_0/0, 30 more preferably 50 mol ^_0/0 force S, and most preferably 35 to 45 mol%. A pattern can be obtained by setting it to 20 mol% or more, and a balance with other structural units can be achieved by setting it to 60 mol% or less.

Yes

[0055] (A- 12) component, in addition to the structural unit (a5), Shi preferred to have a structural unit _(a 6) derived Atarinore ester force having Rataton ring les. The structural unit (a6) is effective in increasing the adhesion of the resist film to the substrate and increasing the hydrophilicity with the developer.

In the structural unit (a6), a lower alkyl group or a hydrogen atom is bonded to the α-position carbon atom. The lower alkyl group bonded to the α-position carbon atom is the same as described for the lower alkyl group in the structural unit (a5), and is preferably a methyl group.

Examples of the structural unit (a6) include a structural unit in which a monocyclic group composed of a ratatone ring or a polycyclic cyclic group having a rataton ring is bonded to the ester side chain portion of the acrylate ester. At this time, the Rataton ring means one ring containing the -o-c (o) structure, and this is counted as the first ring. Therefore, here, in the case of only a ratatone ring, it is called a monocyclic group, and in the case of having another ring structure, it is called a polycyclic group regardless of the structure.

As the structural unit (a6), for example, there is a monocyclic group obtained by removing one hydrogen atom from γ-petit-mouth rataton, or a polycyclic group obtained by removing one hydrogen atom from a rataton-containing bicycloalkane. And the like.

More specifically, the structural unit (a6) is preferably at least one selected from the following general formulas (IV ") to (VII").

[0056] [Chemical 11]

[In the general formula (IV "), R represents a hydrogen atom or a lower alkyl group, and R ⁵ and R ° each independently represents a hydrogen atom or a lower alkyl group.]

[Chemical 12]

[In the formula (V "), R is a hydrogen atom or a lower alkyl group, and m is 0 or 1.]

[0058] [Chemical 13]

[In the general formula (VII "), R represents a hydrogen atom or a lower alkyl group.]

[0060] In the general formulas (IV ") to (VII"), the hydrogen atom or lower alkyl group of R is the description of the hydrogen atom or lower alkyl group of R in the general formulas (Γ) to (ΠΓ). It is the same. In the general formula (IV "),

R ⁶ is independently a hydrogen atom or a lower alkyl group, preferably a hydrogen atom. In R ⁵ and R ⁶ , the lower alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The methyl group is preferred industrially.

[0061] Among the structural units represented by the general formulas (IV ") to (VII"), the structural unit represented by (IV ") is represented by inexpensive and industrially preferred (IV"). Among the structural units, R-Catyl group, And R ⁶ is a hydrogen atom, and the position of the ester bond between the methacrylic acid ester and γ-butyrolatatatone is α-methacryloyloxy- _{butyrolacton,} which is the α-position on the Lataton ring! /.

The structural unit ( _a6 ) can be used alone or in combination of two or more.

(A- 12), the amount of the structural unit (a6) is, (A- 12) relative to the combined total of all structural units constituting the component, 20 to 60 Monore ^_0/0 Ca Preferably, 20 to 50 Monore ⁰ / ₀ preferably from mosquitoes, and most preferably 30 to 45 mol%. Improved lithography properties by a 20 mole ^_0/0 or more, can be balanced with the other structural units by a 6 0 mol% or less.

[0062] The component (A-12) is added to the structural unit (a5) or the structural unit (a5) and

In addition to (a6), it is preferable to further have _a structural unit (a7) derived from an acrylate ester containing a polar group-containing polycyclic group! /.

By the structural unit (a7), the hydrophilicity of the entire component (A-12) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved.

In the structural unit (a7), a lower alkyl group or a hydrogen atom is bonded to the α-position carbon atom. The lower alkyl group bonded to the α-position carbon atom is the same as described for the lower alkyl group in the structural unit (a5), and is preferably a methyl group.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and an amino group, and a hydroxyl group is particularly preferable.

As the polycyclic group, among the aliphatic cyclic groups exemplified in the “acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group” which is the unit (a5), a polycyclic group is appropriately selected. Select and use it.

The structural unit (a7) is preferably at least one selected from the following general formulas (VIII ″) to (IX ″).

[0063] [Chemical 15]

[In the general formula (VIII "), R is a hydrogen atom or a lower alkyl group, and n is an integer of 1 to 3.]

[0064] R in the general formula (VIII ") is the same as R in the above formulas (Γ) to (ΠΓ).

In the general formula (VIII "), it is preferable that η is 1 and the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0065] [Chemical 16]

-.. (IX »)

[In the general formula (IX "), R is a hydrogen atom or a lower alkyl group, and k is an integer of !!-3.]

[0066] R in the general formula (IX ") is the same as R in the above formulas (Γ) to (ΠΙ").

In general formula (IX "), k is preferably 1. In addition, it is preferable that the cyan group is bonded to the 5th or 6th position of the norbornyl group! /.

[0067] The structural unit (a7) can be used alone or in combination of two or more.

In component (A-12), the proportion of structural unit (a7) is the total number of structural units constituting component (A-12) The total of 10 to 50 Monore ^_0/0 Ca Preferably, preferably from 15 to 40 Monore ^_0/0 Ca, more preferably 20 to 35 mol%. Lithographic properties are improved by setting it to 10 mol% or more, and balancing with other structural units can be achieved by setting it to 50 mol% or less.

[0068] In the component (A-12), the total of these structural units (a5) to (a7) is 70 to 100 mol with respect to the total of all the structural units constituting the component (A-12). % Is preferred from 80 to; more preferably 100 mol%.

[0069] The component (A-12) may contain a structural unit (a8) other than the structural units (a5) to (a7).

As the structural unit _(a 8), is classified as one of the above structural units (a5) ~ (a7) it! /, Such a limitation in particular as long as other configurations Unit les.

For example, a structural unit containing a polycyclic aliphatic hydrocarbon group and derived from an (α-lower alkyl) ester is preferable. The polycyclic aliphatic hydrocarbon group is appropriately selected from, for example, polycyclic ones among the aliphatic cyclic groups exemplified in the aforementioned “acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group”. Can be used. In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, a norbornyl group, and an isobornyl group is preferable in terms of industrial availability. The structural unit (a8) is most preferably an acid non-dissociable group.

As the structural unit (a8), specifically, the structural unit represented by the following general formulas (X ") to (XII") is exemplified by the force S.

[0070] [Chemical 17]

(In the formula, R is a hydrogen atom or a lower alkyl group.)

[0071] [Chemical 18]

(In the formula, R is a hydrogen atom or a lower alkyl group.)

[0072] [Chemical 19]

'·' Is II "}

(In the formula, R is a hydrogen atom or a lower alkyl group.)

[0073] In general formulas (X ") to () Γ), the hydrogen atom or lower alkyl group of R is the same as described above for the hydrogen atom or lower alkyl group of R in formulas (Γ) to (ΠΓ). In the case of having the structural unit (a8), the proportion of the structural unit (a8) in the component (A—12) is based on the total of all structural units constituting the component (A—1 2); -25 mol% is preferred 5-20 mol% is more preferred.

[0074] The component (A-12) is preferably a copolymer having at least the structural units (a5), (a6) and (a7). Examples of such a copolymer include a copolymer composed of the structural units (a5), (a6) and (a7), and a structural unit (a5), (a6), (a7) and (a8). A copolymer etc. can be illustrated. [0075] The component (A-1) can be obtained by polymerizing the monomer related to the structural unit by a known method. For example, it can be obtained by polymerizing the monomers related to each structural unit by known radical polymerization using a radical polymerization initiator such as azobisisobutyl nitrile (AIBN).

Component (A-1) is a mass average molecular weight (polystyrene equivalent mass average molecular weight by gel permeation chromatography, the same shall apply hereinafter) 30000 or less is preferred 20000 or less force S preferably 12000 or less More preferably. The lower limit is preferably 4000 or more, and more preferably 5000 or more, from the viewpoints of suppressing pattern collapse and improving resolution as long as 2000 is exceeded.

[0076] [(A-2) component]

As the component (A-2), a low molecular compound having a molecular weight of 500 or more and 2000 or less and having an acid dissociable, dissolution inhibiting group X or X ′ as exemplified in the above description of the component (A-1) Is preferred. Specific examples include those in which some or all of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable, dissolution inhibiting group X or X ′.

The component (A-2) contains, for example, part or all of the hydrogen atoms of the hydroxyl group of a low molecular weight phenolic compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with the above-mentioned acid dissociable, dissolution inhibiting group are preferably used from those which are preferred.

Examples of such a low molecular weight phenolic compound include the following. Bis (4-hydroxyphenol) methane, bis (2,3,4 trihydroxyphenyl) methane, 2- (4hydroxyphenyl) 2- (4, monohydroxyphenol) propane, 2- (2, 3, 4— Trihydroxyphenyl) 1 2— (2, 3, 3, 4, 1 Trihydroxyphenol) Propane, Tris (4 — Hydroxyphenol) Methane, Bis (4 Hydroxy 1, 3, 5 Dimethylphenyl) 1-2 Hydroxyphenylmethane, bis (4hydroxy-1,2,5 Dimethylphenyl) 1-2 Hydroxyphenylmethane, bis (4-hydroxy-1,3,5-dimethylphenyl) 1,3,4-dihydroxyphenylmethane Bis (4-hydroxy-1,2,5-dimethylphenyl) -1,3,4 dihydroxyphenylmethane, bis (4-hydroxy-3-methylphenyl) -1,3,4-dihydroxyphenol Nylmethane, bis (3-cyclohexyl 4-hydroxy-6-methylphenyl) 4-hydroxyphenylmethane, bis (3-cyclohexyl 4-hydroxy-1-6-methylphenyl) —3, 4-dihydroxyphenyl Methane, (4-Hydroxyphenol) isopropyl] 4 [1, 1 Bis (4-hydroxyphenol) ethyl] 2 of formalin condensates of phenols such as benzene, phenol, m-cresol, p-taresol or xylenol , 3, and 4 nuclei. Of course, it is not limited to these.

The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

[0077] In the present invention, the component (A) may have light absorption or may not have light absorption. In view of excellent effects of the present invention, the component (A) preferably has a light absorptivity. That is, since the component (A) has light absorptivity, the amount of the component (C) to be blended to achieve a desired absorbance can be reduced. Therefore, it is possible to reduce risks that may occur due to the inclusion of the component (C), for example, generation of sublimation products due to heating during film formation, deterioration of yield associated therewith, generation of precipitates when used as a solution, etc.

Yes

For example, among the organic compounds listed above, those having a molecular structure that absorbs light of the wavelength of an exposure light source used in thermal lithography 1 have light absorption.

[0078] As the component (A), one type may be used alone, or two or more types may be used in combination.

[0079] <(B) component>

The component (B) is a component that generates an acid by the action of heat. Here, “generating an acid by the action of heat” means generating an acid by heating at 80 ° C. or more and 200 ° C. or less.

As the component (B), conventionally known ones as acid generators for chemically amplified resists can be appropriately selected and used. Examples of such acid generators include onium salt-based acid generators such as odonium salts and sulfonium salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly ( There are various known diazomethane acid generators such as bissulfonyl) diazomethanes, nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

These acid generators are generally photoacid generators (PAG) that generate acid upon exposure. It also functions as a thermal acid generator (TAG) that generates acid by the action of heat, S, known as). Therefore, as component (B), it is possible to use the PAG used in conventional photolithography for IJ.

[0080] Specific examples of the ion salt-based acid generator include diphenyl trifluoromethane sulfonate, (4-methoxyphenol nitrile) phenoxy trifluoromethane sulfonate, bis ( p tert butyl phenyl trifluoromethane sulfonate, triphenyl sulfo trifluoromethane sulfonate, (4-methoxyphenyl) diphenyl sulfonyl trifluoromethane sulfonate, (4 methylphenol) Diphenylsulfonium naphthololebutane sulfonate, (p tert butylenophenenole) diphenenoles sulfonate, bis (p tert butyl phenenole) jordon nononafluorobutane sulfonate, triphenylsulfonumnona Fluorobutane sulfonate is mentioned. Of these, onium salts having fluorinated alkyl sulfonate ions as anions are preferred.

[0081] Examples of oxime sulfonate compounds include α- (methylsulfonyloxyimino) -phenylacetonitrile, a- (methylsulfonyloxyimino) -p-methoxyphenylacetoni 卜 zinore, α- (卜!; Funore, Romechinoresnore, Honore, Kisimimino) -F: Nino Rare! ; Nore, α-(卜 Rifluoromethylsulfonyloxyimino) -ρ-methoxyphenylacetonitrile, a-(Ethenylsulfonyloxymino) -p-methoxyphenylacetonitrile, α-(Propylsulfonoxyximino) ) -Ρ -methylphenylacetonitrile, a-(methylsulfonyloxyimino) -P -bromophenylnitrile and the like. Of these, α- (methylsulfonoxyximino) -ρ-methoxyphenylacetonitrile is preferred! /.

[0082] Specific examples of the diazomethane acid generator include bis (isopropylsulfonyl) diazomethane, bis (ρtoluenesulfoninole) diazomethane, bis (1,1-dimethylethylsulfininole) diazomethane, and bis (cyclohexino). (Resnolehoninole) diazomethane, bis (2,4 dimethylphenylsulfonyl) diazomethane, and the like.

[0083] As the component (ii), one type may be used alone, or two or more types may be used in combination. In the positive resist composition of the present invention, the content of the component (B) is;! To 20 parts by mass, preferably 2 to 10 parts by mass with respect to 100 parts by mass of the component (A). When the amount is not less than the lower limit of the above range, the pattern is sufficiently formed, and when the amount is not more than the upper limit of the above range, the uniformity of the solution is easily obtained and good storage stability is obtained.

[0084] <Component (C)>

The component (C) is not particularly limited as long as it is an organic compound that absorbs light having the wavelength of the exposure light source used in thermal lithography. Depending on the wavelength of the exposure light source used, the strength of a commercially available dye, Choose from the appropriate choices.

Whether or not the dye absorbs light of the wavelength of the exposure light source used can be determined by referring to a pamphlet or the like provided by the manufacturer, or by a conventional method using a spectrophotometer. .

Usually, as the chemically amplified resist, light having a wavelength of 250 nm or less, such as an excimer laser such as a KrF excimer laser or an ArF excimer laser, or a light source having a shorter wavelength is generally used. . Such chemically amplified resists are usually not sensitive to light of wavelengths longer than 365 nm, such as visible light lasers. Therefore, as the component (C), a compound that absorbs light having a wavelength of 350 nm or more is preferred, and a compound that absorbs light having a wavelength of 365 nm or more is more preferred. ,. In particular, a dye that absorbs light having a wavelength of 350 to 800 nm is preferable, and a dye that absorbs light having a wavelength of 350 to 550 nm is more preferable. A dye that absorbs light having a wavelength of 350 to 450 nm is most preferable.

For example, compounds that absorb light at wavelengths around 400 nm include compounds that are mainly used as yellow dyes. Specific examples include trade names: OY-105, OY-107, OY-108. , OY—129, OY—3G, OY—GG—S (above, manufactured by Orient Chemical Co., Ltd.), Diaresin Yellow F, Diaresin A (above, manufactured by Mitsubishi Chemical), Soldan Yellow GRN (above, manufactured by Chugai Kasei Co., Ltd.), Sumiplast Yellow GG, Sumiplast Yellow F5G, Sumiplast Yellow FG (Sumitomo Chemical Co., Ltd.), CH-1002 (Dai-Tokemix Co., Ltd.), etc.

[0085] As the component (C), one type may be used alone, or two or more types may be mixed and used. The compounding amount of component (c) is not limited as long as the absorbance of the resist film formed using the positive resist composition is 0.08 or more per film thickness lOOnm at the wavelength of the exposure light source. What is necessary is just to adjust suitably according to a desired light absorbency, the kind of (C) component to be used, whether the said (A) component absorbs the wavelength of an exposure light source, etc.

The preferred compounding amount of component (C) is that it is added at a ratio of! To 80% by mass, more preferably 3 to 75% by mass, and particularly preferably 4 to 70 mass%, more preferably 5 to 65 mass%, most preferably 8 to 65 mass%. If it is 1% by mass or more, the absorbance is improved. When it is 80% by mass or less, the coatability is improved.

[0086] <Optional component>

The positive resist composition of the present invention is an optional component in order to improve the resist pattern shape, stability of standing exposure or the latent image formed by the pattern-wise exposure of tne resist layer, etc. It is preferable to contain a nitrogen-containing organic compound (D 2) (hereinafter referred to as “component (D)”).

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

Here, the lower aliphatic amine is an alkyl or alkyl alcohol amine having 1 to 5 carbon atoms. Examples of the secondary and tertiary amines include trimethylamine, jetamine, and triethylamine. Amines, di-n-propylamine, tri-n-propylamine, tripentylamine, diethanolamine, triethanolamine, triisopropanolamine, etc., but particularly those such as triethanolamine and triisopropanolamine. 3rd grade alkanolamine is preferred!

Any one of these may be used alone, or two or more may be used in combination.

In the positive resist composition of the present invention, the component (D) is usually used in the range of 0.0;! To 5.0 parts by mass with respect to 100 parts by mass of the component (A).

[0087] In addition, the positive resist composition of the present invention may further comprise an optional component for the purpose of preventing deterioration of sensitivity due to the blending with the component (D) and improving the pattern shape, stability with time, and the like. As a component, it is possible to contain an organic carboxylic acid or phosphorus oxoacid or a derivative thereof (E) (hereinafter referred to as (E) component). In addition, the component (D) and the component (E) can be used in combination, or one of them 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 those esters, phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid Phosphonic acid such as n-butyl ester, phenylphosphonic acid, diphenyl ester of phosphonic acid, dibenzyl ester of phosphonic acid and derivatives thereof, phosphinic acid such as phosphinic acid, phenylphosphinic acid and esters thereof Derivatives such as phosphonic acid are particularly preferred among these! /.

As the component (E), one type may be used alone, or two or more types may be used in combination.

Component (E) is usually used at a ratio of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0088] The positive resist composition of the present invention further improves the coating properties of the miscible additive, for example, an additional resin for improving the performance of the coating film of the resist composition, if desired. A surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, and the like can be appropriately contained.

[0089] The positive resist composition of the present invention is preferred as described above! /, That is, different from the positive resist composition containing the component (A), the component (B) and the component (C). As an embodiment, a base material component (Α ′) (hereinafter referred to as (Α ′) component) which increases alkali solubility by the action of an acid and absorbs light having a wavelength of an exposure light source used in thermal lithography. Examples thereof include a positive resist composition containing the component (ii) as an essential component.

The positive resist composition of this embodiment may not contain the component (C). That is, since the (Α ′) component has a light absorption ability to absorb light having the wavelength of the exposure light source, and also has a function as the (C) component, the (C) component. Even if it does not contain, the effect of the present invention can be obtained. Since it does not have to contain the component (C), It is possible to reduce risks that may occur due to the inclusion of the component (C), such as generation of fine products, deterioration of the yield associated therewith, and generation of precipitates when formed into a solution.

Examples of the (Α ′) component include those having a molecular structure that absorbs light having a wavelength of an exposure light source used in thermal lithography, among the organic compounds mentioned as the (Α) component.

The positive resist composition of this embodiment may contain a component other than the component (Α ′) and the component (Β). Examples of the other components include the above-described (ii) component, (ii) component, (C) component, and other optional components. In particular, when the component (C) is used in combination, the light absorption capacity is relatively low as the component (Α ′), and it is preferable because the desired absorbance can be achieved even if it is used!

The positive resist composition of the present invention can be produced by dissolving each of the above components in an organic solvent (S) (hereinafter referred to as (S) component).

As the component (S), any component can be used as long as it can dissolve each component used to form a uniform solution. Any one of conventionally known solvents for resist compositions can be used. More than one species can be appropriately selected and used.

Specific examples include latones such as γ-butyrolatatatone, acetone, methinoreethinoleketone, ketones such as cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycolate, ethylene glycol monoremonoacetate, diethylene Glyconole, diethyleneglycol mononole monoacetate, propylene glycolenole, propylene glycolenole monoacetate, propylene glycol monomethyl ether acetate (PGMEA), dipropylene glycolenole, or monopropylene glycolenole monoacetate monomethylenoateol, mono Ethyleneate, polyhydric alcohols such as monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof, cyclic ethers such as dioxane, lactic acid methyl And esters of lactic acid ethyl (EU, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc. Among these, 2- Ptanone, PGMEA, EL, and propylene glycol monomethyl ether (PGME) are preferred, and these organic solvents may be used alone or as a mixed solvent of two or more types.

These organic solvents may be used alone or as a mixed solvent of two or more. The amount of the component (s) to be used is not particularly limited, but an amount that allows the positive resist composition of the present invention to be a liquid having a concentration that can be applied onto a support is used.

[0091] In addition, the positive resist composition of the present invention has an amount such that the absorbance of the resist film to be formed is 0.08 or more per lOOnm of film thickness with respect to a commercially available chemically amplified positive resist composition ( It can also be produced by adding (predetermined amount) component (C) and dissolving it.

Usually, as described above, a commercially available chemically amplified positive resist composition contains the component (A) and a photoacid generator component that generates acid upon exposure. The agent component is the same as the component (B). Therefore, the positive resist composition of the present invention can be produced by adding the predetermined amount of the component (C) to a commercially available chemically amplified positive resist composition.

[0092] As described above, the resist film formed using the chemically amplified positive resist composition for thermal lithography of the present invention has a film thickness of 0.1 per 1 lOOnm at the wavelength of the exposure light source used in thermal lithography. Absorbance of 08 or higher. Therefore, in thermal lithography, when the resist film absorbs light irradiated from the exposure light source, heat at a temperature sufficient to generate acid from the acid generator component in the resist film is generated. . Therefore, a resist pattern can be formed on the resist film by thermal lithography.

[0093] <Method for forming resist pattern>

The resist pattern forming method of the present invention is a step of forming a resist film on a support using the above-mentioned chemically amplified positive resist composition for thermal lithography of the present invention (hereinafter referred to as a resist film forming step). A step of selectively exposing the resist film with light having a wavelength of absorbance of 0.08 or more per film thickness lOOnm of the resist film (hereinafter referred to as an exposure step), and the resist. It includes a step of developing a film to form a resist pattern (hereinafter referred to as a developing step).

The resist pattern forming method of the present invention can be performed, for example, as follows.

[0094] (Resist film forming step)

In this step, first, the positive resist composition for thermal lithography of the present invention is applied onto a support with a spinner or the like, and a pre-beta (post-private ( PAB))) for 40-; 120 seconds, preferably 60-90 seconds A resist laminate is obtained by forming a film.

The support is not particularly limited, and a conventionally known one can be used. For example, a substrate for an electronic component or a substrate on which a predetermined wiring pattern is formed can be exemplified. More specifically, examples include silicon substrates such as silicon eno, copper, chromium, iron, and aluminum, and glass (quartz glass) substrates. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used. In addition, an inorganic and / or organic antireflection film may be provided on the substrate.

The thickness of the resist film is preferably 30 to 1000 nm, more preferably 50 to 600 nm, and still more preferably 50 to 450 nm. By setting it within this range, there are effects such that a resist pattern can be formed with high resolution and sufficient resistance to etching can be obtained.

[0095] (Exposure process)

Next, the obtained resist laminate is selectively exposed using light having a wavelength at which the absorbance per 100 nm thickness of the resist film is 0.08 or more as an exposure light source.

As the exposure light source, a visible light laser that favors light having a wavelength of 350 nm or more is more preferred, and light having a wavelength of 350 to 450 nm is particularly preferred. Components contained in normal chemical amplification type positive resist compositions (for example, component (A) and component (B) described above) are light having a wavelength of 250 nm or less, such as KrF excimer laser, ArF excimer laser, etc. In general, an excimer that absorbs light of a shorter wavelength than that, or that absorbs little or no light is generally used. Therefore, by using light having a wavelength of 350 nm or more, the influence of the light on the resist film can be reduced, and the ability to perform thermal lithography well is reduced.

For selective exposure, a commercially available exposure apparatus can be appropriately selected and used according to the light source to be used. For example, when using a visible light laser, the NEO-500 (semiconductor laser with a wavelength of 405 nm) manufactured by Norstec can be used. This device is a device that performs drawing by irradiating an object (resist laminate) with a semiconductor laser beam condensed by a lens.

[0096] In this step, when the surface of the resist laminate (resist film side) is irradiated with light, the light is absorbed by the resist film. And part of the resist film that absorbs light (light absorption part) Generate | occur | produces and an acid generate | occur | produces from the (B) component which exists in a light absorption part by this heat, The alkali solubility of (A) component increases by the effect | action of this acid. For this reason, when the Al development is performed in the subsequent development process, the resist film in the portion where the acid is generated is removed, and the resist film in the other portion is left without being removed to form a resist pattern.

When the light is irradiated, the heat distribution of the heat generated in the light absorption part is the same as the intensity distribution of the absorbed light. For example, in the case of a light spot, the light intensity increases as it is closer to the center. The heat that goes up becomes higher in the center. Since the reaction of thermal lithography occurs when the temperature of the heated resist film becomes a predetermined temperature (heat sensitive temperature) or higher, a high temperature portion (heat spot) higher than the heat sensitive temperature at the center of the light spot is generated. Contributes to thermal lithography. Since the diameter of the heat spot is smaller than the spot diameter of the light, drawing can be performed with a diameter finer than the spot diameter of the irradiated light, and as a result, a fine pattern can be formed.

The thermal temperature is usually in the range of 140 to 300 ° C., although it varies depending on the type of component (A) and component (B) used.

[0097] After the selective exposure, PEB (post-exposure heating) is preferably applied to the resist laminate at a temperature of 80 to 150 ° C for 40 to 120 seconds, preferably 60 to 90 seconds.

[0098] (Development process)

Then, this alkali developer solution, for example 0.5 05～; 10 mass ^_0/0, preferably developed using a 0.05 to 3 mass% of tetramethylammonium Niu arm hydroxide (TMAH) aqueous solution. Thereby, the exposed portion of the resist film is selectively dissolved and removed to form a resist pattern.

[0099] An etching process for etching the support using the formed resist pattern as a mask pattern may be further performed on the resist laminated body on which the resist pattern is formed as described above.

For example, when using a support provided with an organic film (lower layer film) on a substrate, the resist pattern of the resist film is transferred to the organic film by etching the organic film, and the substrate is then transferred to the substrate. High aspect ratio patterns can be formed.

The organic film can be etched using a conventionally known etching method. Etching with oxygen plasma is preferred among lie etching.

Example

[0100] [Example 1] (Preparation of positive resist composition 1)

First, the following components were mixed and dissolved to prepare a positive resist composition 1.

• Component (A): Resin 1 (11.97 parts by mass) and Resin 2 (5.13 parts by mass).

• Component (B): acid generator 1 (0.56 parts by mass).

• Component (D): Triethanolamine (0 · 009 parts by mass).

• Component (E): salicylic acid (0.019 parts by mass).

• Additive: Dimethylacetamide (0.463 parts by mass).

• Organic solvent: PGMEA (81.8 parts by mass).

• Organic solvent: 2-Heptanone (630 parts by weight).

• Yellow dye OY—108 (manufactured by Orient Chemical) (1.0 parts by mass).

[0101] In the above composition, the resin 1 is a resin having a mass average molecular weight of 8000 composed of two kinds of structural units represented by the following formula (1), and m and n in the formula (1) are each the resin The ratio of each structural unit in the unit (unit: mol%), m / n = 61/39.

Resin 2 is a resin having a weight average molecular weight of 8000 composed of two types of structural units represented by the following formula (2), and m and n in formula (2) are the proportion of each structural unit in the resin, respectively. (

twenty two

Unit: the molar ^_0/0), a m / n = 61/39.

twenty two

Acid generator 1 is a compound represented by the following formula (3).

[0102] [Chemical 20]

(Measurement of absorbance)

Using a spin coater (manufactured by MIKASA), the positive resist composition 1 prepared above was applied onto a 2-inch quartz substrate and beta-treated at 230 ° C for 15 minutes to form a resist film with a thickness of 100 ηm. A sample for measurement was produced by forming a film.

About this sample, the light absorbency of the said resist film was measured on the following measurement conditions using "Shimadzu self-recording spectrophotometer UV-3100 PCJ" by Shimadzu Corporation.

[Measurement condition]

Measurement wavelength range: 600nm ~ 200nm.

Absorbance measurement range: 0-2.5Abs.

Scan speed: fast.

Slit width: 2.0 belly.

Sampling pitch: AUTO.

Baseline: Air [Equipment Reference for Background Correction], New Stone English substrate [Sample side reference for background correction].

[0104] From the absorbance of the resist film at a wavelength of 405 nm obtained by the above measurement and the film thickness of the resist film, the absorbance per film thickness lOOnm at a wavelength of 405 nm was calculated. As a result, the absorbance at a wavelength of 405 ηm of the resist film formed using the positive resist composition 1 was 0.08 / film thickness lOOnm.

[0105] (Confirmation of pattern formation)

Using a spin coater (manufactured by MIKASA), apply the positive resist composition 1 prepared above on a glass substrate that has been treated with hexamethyldisilazane (HMDS) (70 ° C, 7 minutes), A resist film (film thickness lOOnm) was formed by heating at 110 ° C for 90 seconds on a hot plate. Next, in the nano-processing apparatus NEO-500 (manufactured by Pulstec Industrial Co., Ltd.), the resist film was irradiated with blue laser light (semiconductor laser wavelength: 405 nm) at an output of 10 mW. The substrate was heated at 110 ° C. for 90 seconds, immersed in 0.24 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds, further washed with pure water, and then heated on a hot plate at 0 ° C. for 60 seconds. Heated. Then, the surface of the substrate was observed using a scanning electron microscope (SEM). As a result, a resist pattern in which holes with an inner diameter of 900 nm were arranged at an equal interval (pitch 1200 nm) and holes with an inner diameter of 330 nm were arranged at an equal interval (600 nm pitch). The formation of the resist pattern arranged in) was confirmed.

[Example 2]

In Example 1, yellow dye OY-108 (manufactured by Orient Chemical Co., Ltd.) 1.0 Same as Example 1 except that 1.0 mass part of yellow dye CH-1002 (manufactured by Daito Chemix) was used instead of 1.0 mass part Thus, a positive resist composition 2 was prepared.

When the absorbance was measured using the positive resist composition 2 in the same manner as in Example 1, the absorbance of the resist film formed using the positive resist composition 2 at a wavelength of 405 nm was 0.32. / The film thickness was 100 bellies.

In addition, pattern formation was confirmed using positive resist composition 2 in the same manner as in Example 1. As a result, a resist pattern in which holes with an inner diameter of 900 nm were arranged at equal intervals (pitch 1200 nm) and holes with an inner diameter of 330 nm were obtained. It was confirmed that resist patterns were formed at equal intervals (pitch: 600 nm). [Comparative Example 1]

In Example 1, yellow dye OY-108 (manufactured by Orient Chemical Co., Ltd.) 1.0 Example except that yellow dye OY-GG-S (manufactured by Orient Chemical Co., Ltd.) 0.55 parts by mass was used instead of 1.0 part by mass. In the same manner as in Example 1, a positive resist composition 3 was prepared.

The absorbance was measured using the positive resist composition 3 in the same manner as in Example 1. As a result, the absorbance of the resist film formed using the positive resist composition 3 at a wavelength of 405 nm was 0.07. / The film thickness was 100 bellies.

Further, when pattern formation was confirmed using the positive resist composition 3 in the same manner as in Example 1, the resist pattern was not resolved.

[Comparative Example 2]

In Example 1, the yellow dye OY-108 (manufactured by Orient Chemical Co., Ltd.) 1.0 Example 1 was used except that the yellow dye OY-105 (manufactured by Orient Chemical Co., Ltd.) was changed to 0. Similarly, a positive resist composition 4 was prepared.

The absorbance was measured using the positive resist composition 4 in the same manner as in Example 1. As a result, the absorbance of the resist film formed using the positive resist composition 4 at a wavelength of 405 nm was 0.07. / The film thickness was 100 bellies.

Further, when the pattern formation was confirmed using the positive resist composition 4 in the same manner as in Example 1, the resist pattern was not resolved.

[Comparative Example 3]

In Example 1, yellow dye OY-108 (manufactured by Orient Chemical Co., Ltd.) 1. Similarly, a positive resist composition 5 was prepared.

When the absorbance was measured using the positive resist composition 5 in the same manner as in Example 1, the absorbance at a wavelength of 405 nm of the resist film formed using the positive resist composition 5 was 0.06. / The film thickness was 100 bellies.

Further, when the pattern formation was confirmed using the positive resist composition 5 in the same manner as in Example 1, the resist pattern was not resolved.

[0110] [Comparative Example 4] A positive resist composition 6 was prepared in the same manner as in Example 1 except that the yellow dye OY-108 was not added.

The absorbance was measured using the positive resist composition 6 in the same manner as in Example 1. As a result, the absorbance of the resist film formed using the positive resist composition 6 at a wavelength of 405 nm was 0.06. / The film thickness was 100 bellies.

Further, when the pattern formation was confirmed using the positive resist composition 6 in the same manner as in Example 1, the resist pattern was not resolved.

[0111] As shown in the above results, in Examples 1 and 2 in which the absorbance of the resist film to be formed at the wavelength of the exposure light source (405 nm) is 0.08 / thickness lOOnm or more, the resist pattern Was formed.

On the other hand, resist patterns could not be formed in Comparative Examples 1 to 3 in which the absorbance of the resist film to be formed was 0.07 / thickness lOOnm or less at the wavelength of the exposure light source (405 nm).

From these results, it is clear that the resist pattern forming force S in Examples 1 and 2 is due to the fact that the blue laser light directly acts on the resist film, that is, the one based on thermal lithography rather than the one based on photolithography. It is.

Industrial applicability

The present invention relates to a chemically amplified positive resist composition for thermal lithography capable of forming a resist pattern by thermal lithography, and a resist pattern forming method using the chemically amplified positive resist composition for thermal lithography This is extremely useful in industry.

Claims

The scope of the claims

[1] A chemically amplified positive resist composition for thermal lithography for forming a resist film used in thermal lithography,

The resist film formed by using the chemical amplification type positive resist composition for thermal lithography has a thermal absorption of 0.08 or more per 10 Onm thickness at the wavelength of the exposure light source used in the thermal lithography. A chemically amplified positive resist composition for lithography.

[2] A base material component (A) whose alkali solubility is increased by the action of an acid, an acid generator component (B) which generates an acid by the action of heat, and a dye that absorbs light having a wavelength of the exposure light source The chemical amplification type positive resist composition for thermal lithography according to claim 1, comprising (C).

[3] A base material component (Α ′) that increases alkali solubility by the action of an acid and absorbs light having the wavelength of the exposure light source, and an acid generator component (B) that generates an acid by the action of heat The chemically amplified positive resist composition for thermal lithography according to claim 1, comprising:

[4] A step of forming a resist film on the support using the chemically amplified positive resist composition for thermal lithography according to claim 1 or 2, the resist film thickness with respect to the resist film A resist pattern forming method, comprising: a step of performing selective exposure using light having a wavelength of absorbance of 0.08 or more per lOOnm; and a step of developing the resist film to form a resist pattern.

[5] A chemically amplified positive resist composition for thermal lithography for forming a resist film used in thermal lithography,

A substrate component (A) whose alkali solubility is increased by the action of an acid, an acid generator component (B) which generates an acid by the action of heat, and a wavelength of 350 ηm or more of an exposure light source used in the thermal lithography. Containing a dye (C) that absorbs the light of

The chemical amplification type positive resist composition for thermal lithography, wherein the amount of the dye (C) is 8 to 65% by mass with respect to the component (A).

[6] A step of forming a resist film on the support using the chemically amplified positive resist composition for thermal lithography according to claim 5, wherein the resist film is selected using light having a wavelength of 350 nm or more. A step of performing a periodic exposure, and developing the resist film to form a resist pattern Forming a resist pattern.