JP2998095B2 - Resist coating composition solution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a resist coating composition solution. More particularly, the present invention relates to a resist coating composition solution capable of forming a resist useful for fine processing using various radiations such as far-ultraviolet rays such as an excimer laser.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, the processing size in lithography has been reduced in order to obtain a higher degree of integration. There is a need for a technique capable of performing fine processing with good reproducibility. Therefore, even in the resist used for microfabrication, 0.5%
Although it is necessary to form a pattern with a size of less than μm with high precision, a conventional method using visible light (wavelength 700 to 400 nm) or near ultraviolet light (wavelength 400 to 300 nm) can form a fine pattern of 0.5 μm or less with high precision. Is extremely difficult to form. Therefore, a shorter wavelength (wavelength 3
A lithography technique using radiation of about 00 nm or less is being studied. Examples of such short-wave radiation include a bright line spectrum of a mercury lamp (wavelength: 254 nm), Kr
Examples include far ultraviolet rays such as F excimer laser (wavelength: 248 nm), charged particles such as X-rays such as synchrotron radiation, and electron beams. Of these, lithography using an excimer laser is particularly high. For reasons of output, high efficiency characteristics, etc., it has attracted attention as a "trump card" for microfabrication. For this reason, excimer laser is also used for resists used in lithography.
It is required that a fine pattern of 0.5 μm or less can be formed with high sensitivity, high resolution, and good reproducibility. However, it cannot be said that these conditions are not always sufficiently achieved by a conventional ordinary resist. On the other hand, as a resist suitable for far ultraviolet rays such as excimer laser,
“Chemically amplified resists” are attracting attention. This resist uses a radiation-sensitive acid generator that generates an acid upon irradiation with radiation, and improves the sensitivity of the resist by the catalytic action of the acid. There are both positive and negative types. In the positive type, for example, JP-A-59-45439 discloses a composition obtained by combining a resin protected with a t-butyl group or a t-butoxycarbonyl group with a radiation-sensitive acid generator. JP-A-52845 discloses compositions in each of which a resin protected with a silyl group and a radiation-sensitive acid generator are combined. Further, in addition to these, many reports have been made, such as a resist using an acetal group-containing resin (JP-A-2-25850). On the other hand, in the case of the negative type, for example,
No. 44 discloses a composition comprising a combination of a radiation-sensitive acid generator and a crosslinking agent such as methoxymethylmelamine. These conventional chemically amplified resists cause a chemical reaction using an acid generated by irradiation of radiation as a catalyst, thereby changing the solubility of the composition in a developer,
Although it is based on the principle of forming a resist pattern and generally achieves high sensitivity, even if it has the same composition, there is a problem that the sensitivity sometimes drops significantly and a stable sensitivity cannot always be obtained. As one of the reasons why the sensitivity of the resist is not stable, it has been reported that a basic impurity contained in the working atmosphere acts on an acid generated by irradiation with radiation and reduces the catalytic ability of the acid. As a countermeasure, it has been proposed to provide a protective film on the resist film to prevent the influence of the basic impurities (for example, SA MacDonald et al.
PIE, Vol. 1466, p. 2 (1991)). However, even when the above-described protective film is provided, the sensitivity of the resist may still be unstable, and a drastic solution for always achieving a stable resist sensitivity is desired.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resist coating composition solution having particularly excellent stability of resist sensitivity.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on factors affecting the sensitivity of a chemically amplified resist, and as a result, in addition to the above-mentioned basic impurities, metal impurities present in the resist composition were found to be less. The present inventors have obtained a new finding that the catalytic ability of an acid generated by irradiation with radiation has been reduced, and have completed the present invention. That is, the present invention includes a component that generates an acid upon irradiation with radiation (hereinafter, referred to as “exposure”) (hereinafter, referred to as an “acid generator”), and is exposed to light by a chemical reaction catalyzed by the acid. In the solution of the resist coating composition that forms a resist pattern by changing the solubility of the resist coating composition in the developer, the resist coating composition described below is used as the resist composition.
(A), the resist composition (B) or the resist composition
(C) wherein the total content of metals in the solution is not more than 200 ppb in terms of a simple substance. Hereinafter, the present invention will be described in detail.
The configuration and effect will be clear.

[0005] The resist coating composition in the resist coating composition solution of the present invention contains an acid generator, and the solubility of the exposed portion in a developing solution is changed by a chemical reaction caused by the catalytic action of an acid generated by exposure. By
Is intended to form a resist pattern, following resist
Composition (a), resist composition (b) or resist set
Consists of an adult (c) .

(A) (1) an acid generator, and (2)
An alkali-insoluble or alkali-insoluble resin protected by an acid-dissociable group, which becomes alkali-soluble when the acid-dissociable group is dissociated (hereinafter, referred to as an “acid-dissociable group-containing resin”). A positive-type radiation-sensitive resin composition (hereinafter referred to as “resist composition (a)”);

(B) (1) an acid generator, (2) an alkali-soluble resin, and (3) having a property of controlling the alkali solubility of the alkali-soluble resin, being decomposed in the presence of an acid, A positive-type radiation-sensitive resin composition (hereinafter, referred to as "resist composition (b)") containing a dissolution controlling agent having an action of reducing, eliminating or promoting the alkali solubility controlling effect of the alkali-soluble resin;

(C) A negative radiation-sensitive resin composition comprising (1) an acid generator, (2) an alkali-soluble resin, and (3) a crosslinking agent capable of crosslinking the alkali-soluble resin in the presence of an acid. (Hereinafter, referred to as “resist composition (c)”). Hereinafter, these resist compositions will be described.

Acid Generator The acid generator used in the resist coating composition in the resist coating composition solution of the present invention corresponds to the above-mentioned radiation-sensitive acid generator in the chemically amplified resist. Examples of such an acid generator include, for example,
No. 115932, JP-A-60-37549,
JP-A-60-52845, JP-A-63-2921
And onium salts, halogen-containing compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, and the like, which are disclosed in JP-A No. 28, JP-A-1-293339 and the like. These acid generators can be used alone or in combination of two or more. Hereinafter, these acid generators will be described.

Onium salt: Examples of the onium salt include an iodonium salt, a sulfonium salt, a phosphonium salt, a diazonium salt, a pyridinium salt and the like. Preferred onium salts are diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate And so on.

Halogen-containing compound: Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound,
Examples include a haloalkyl group-containing heterocyclic compound.
Preferred halogen-containing compounds include 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, phenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis- (trichloromethyl) -s-triazine and the like. It is.

Diazoketone compound: Examples of the diazoketone compound include 1,3-diketo-
Examples thereof include a 2-diazo compound, a diazobenzoquinone compound, and a diazonaphthoquinone compound. Preferred diazoketone compounds are 1,2-naphthoquinonediazide-4-sulfonyl chloride and 1,2-naphthoquinonediazide-4 of 2,3,4.4'-tetrahydroxybenzophenone.
-Sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane, and the like.

Sulfone compound: Examples of the sulfone compound include β-ketosulfone compounds and β-sulfonylsulfone compounds. Preferred sulfone compounds are 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane and the like.

Sulfonic acid compound: Examples of the sulfonic acid compound include alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters,
And iminosulfonate. Preferred sulfonic acid compounds are benzoin tosylate, tristriflate of pyrogallol, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate and the like.

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

The acid-dissociable group-containing resin in the resist composition (a) is
For example, an acidic functional group such as a phenolic hydroxyl group and a carboxyl group in an alkali-soluble resin described below is substituted with one or more acid-dissociable groups that can be dissociated in the presence of an acid. It is a soluble resin. As used herein, the term “alkali-insoluble or poorly alkali-soluble” refers to a resist composition (a) under alkaline development conditions employed when forming a resist pattern from a resist film formed using the resist composition (a). ) Means that, when a film using only an acid-dissociable group-containing resin is developed, 50% or more of the initial film thickness remains after development.

The acid dissociable group is not particularly limited as long as it has the above properties. Examples thereof include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a silyl group, a germyl group, and an alkoxycarbonyl group. Group, acyl group,
And cyclic acid dissociable groups.

Examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group,
Ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, methoxyphenacyl group,
(Methylthio) phenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group, ethylthiobenzyl group, piperonyl group And the like.

As the 1-substituted ethyl group, for example, 1
-Methoxyethyl group, 1-methylthioethyl group, 1,1
-Dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl group, 1-
Phenoxyethyl group, 1-phenylthioethyl group, 1,
1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzylthioethyl group, 1-cyclopropylethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, α-methylphenacyl group, etc. Can be mentioned.

Examples of the 1-branched alkyl group include an isopropyl group, a sec-butyl group, a t-butyl group,
1,1-dimethylpropyl group, 1-methylbutyl group,
Examples thereof include a 1,1-dimethylbutyl group.

Examples of the silyl group include a trimethylsilyl group, an ethyldimethylsilyl group, a methyldiethylsilyl group, a triethylsilyl group, an isopropyldimethylsilyl group, a methyldiisopropylsilyl group, a triisopropylsilyl group, a t-butyldimethylsilyl group, and a methyldisilyl group. -T-butylsilyl group, tri-t-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group,
And a triphenylsilyl group.

Examples of the germyl group include a trimethylgermyl group, an ethyldimethylgermyl group, a methyldiethylgermyl group, a triethylgermyl group, an isopropyldimethylgermyl group, a methyldiisopropylgermyl group, a triisopropylgermyl group, t-butyldimethylgermyl group, methyldi-t-butylgermyl group, tri-t-
Examples thereof include a butylgermyl group, a phenyldimethylgermyl group, a methyldiphenylgermyl group, and a triphenylgermyl group.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, a t-butoxycarbonyl group and a t-pentyloxycarbonyl group.

Examples of the acyl group include acetyl, propionyl, butyryl, heptanoyl, hexanoyl, valeryl, pivaloyl, isovaleryl, lauryloyl, myristoyl, palmitoyl, stearoyl, oxalyl, malonyl. Group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacoil group, acryloyl group, propioloyl group, methacryloyl group,
Crotonoyl, oleoyl, maleoyl, fumaroyl, mesaconoyl, camphoroyl, benzoyl, phthaloyl, isophthaloyl, terephthaloyl, naphthoyl, toluoyl, hydroatropoyl, atropoyl, cinnamoyl, floyl Groups, a thenoyl group, a nicotinoyl group, an isonicotinoyl group, a toluenesulfonyl group, a mesyl group and the like.

The cyclic acid dissociable group includes, for example, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group,
Cyclohexenyl group, oxocyclohexenyl group, 4-
Methoxycyclohexyl group, tetrahydropyranyl group,
Tetrahydrofuranyl group, tetrahydrothiopyranyl group, tetrahydrothiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, S, S
-Dioxide group, 2-1,3-dioxolanyl group, 2-
Examples thereof include a 1,3-dithiolanyl group, a benzo-2-1,3-dioxolanyl group, and a benzo-2-1,3-dithiolanyl group.

Of these acid dissociable groups, a t-butyl group, a benzyl group, a t-butoxycarbonyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group and a tetrahydrothiofuranyl group are preferred.

The rate of introduction of acid-dissociable groups into the resin having acid-dissociable groups (the ratio of the number of acid-dissociable groups to the total number of acidic functional groups and acid-dissociable groups in the resin having acid-dissociable groups) is as follows: , Preferably 15 to 100%, more preferably 20 to 10%.
0%, particularly preferably 30 to 100%.

The weight average molecular weight (hereinafter, referred to as “Mw”) of the resin containing an acid-dissociable group measured by gel permeation chromatography is preferably from 1,000 to 150,000, more preferably from 3 to 1. 000 to 100,000.

The acid-dissociable group-containing resin has, for example, one or more acid-dissociable groups by introducing one or more acid-dissociable groups into one or more alkali-soluble resins prepared in advance. It can be produced by polymerization or copolymerization of monomers, or polycondensation or copolycondensation of a polycondensation component having one or more acid dissociable groups.

The acid-dissociable group-containing resin used in the resist composition (a) has a property of controlling the alkali solubility of the alkali-soluble resin, and is decomposed in the presence of an acid to form an alkali-soluble resin. It has an effect of reducing, eliminating or promoting the solubility control effect, and falls into the category of the solubility control agent used in the resist composition (b).

These acid-dissociable group-containing resins can be used alone or in combination of two or more. The compounding ratio of the acid generator and the acid-dissociable group-containing resin in the resist composition (A) is such that the acid generator is preferably 0.05 to 20 parts by weight, more preferably 0.05 to 20 parts by weight, per 100 parts by weight of the acid-dissociable group-containing resin. It is preferably 0.1 to 15 parts by weight, particularly preferably 0.5 to 10 parts by weight. When the amount of the acid generator is 0.0
If the amount is less than 5 parts by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by exposure, and if the amount exceeds 20 parts by weight, unevenness in application when applying the resist composition (a) may occur. Or scum may occur during development.

Alkali-soluble resin The alkali-soluble resin used in the resist compositions (b) and (c) contains one or more acidic groups such as a phenolic hydroxyl group and a carboxyl group, which have an affinity for an alkali developing solution. There is no particular limitation as long as it has a functional group and is soluble in an alkaline developer.

As such an alkali-soluble resin,
For example, acidic functionalities such as hydroxystyrene, hydroxy-α-methylstyrene, vinylbenzoic acid, styrylacetic acid, styryloxyacetic acid, (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, and cinnamic acid Examples include a vinyl resin having a repeating unit in which a polymerizable double bond of at least one monomer having a group is cleaved, and a resin having a condensation repeating unit having an acidic functional group such as a novolak resin. .

When the alkali-soluble resin is the above-mentioned vinyl resin, the resin may be composed of only a repeating unit in which the polymerizable double bond of the monomer having an acidic functional group has been cleaved. As long as the resin thus obtained is soluble in the alkali developer, it may further have another repeating unit, if necessary. Examples of such other repeating units include styrene, α-methylstyrene, vinyltoluene, maleic anhydride, (meth) acrylonitrile,
Crotonnitrile, maleinitrile, fumaronitrile, mesaconnitrile, citraconitrile, itaconitrile, (meth) acrylamide, crotonamide,
A polymerizable double bond portion of a monomer containing a polymerizable double bond such as maleamide, fumaramido, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyridine, vinyl-ε-caprolactam, vinylpyrrolidone, or vinylimidazole. Can be cited.

In the polymerization or copolymerization for producing the alkali-soluble resin comprising the vinyl resin, a radical polymerization initiator, an anion polymerization catalyst, a coordination anion polymerization catalyst, A polymerization initiator such as a cationic polymerization catalyst or a polymerization catalyst is appropriately selected, and the polymerization can be carried out in an appropriate polymerization form such as bulk polymerization, solution polymerization, precipitation polymerization, emulsion polymerization, suspension polymerization, or bulk-suspension polymerization. .

When the alkali-soluble resin is a resin having the above-mentioned condensed repeating unit, the resin may be composed of only a novolak resin unit, but as long as the formed resin is soluble in an alkali developing solution. May further have another condensation unit. Such a condensed alkali-soluble resin is obtained by combining one or more phenols and one or more aldehydes, together with a polycondensation component which may optionally form another condensation-based repeating unit, in the presence of an acidic catalyst.
It can be produced by polycondensation or copolycondensation in an aqueous medium or a mixed medium of water and a hydrophilic solvent.

In this case, the phenols include
For example, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol,
2,5-xylenol, 3,4-xylenol, 3,5
-Xylenol, 2,3,5-trimethylphenol,
Examples of the aldehydes include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, and the like.
Phenylacetaldehyde and the like can be mentioned.

Although the content of the repeating unit having an acidic functional group in the alkali-soluble resin cannot be specified unconditionally depending on the type of other repeating units contained as necessary,
Usually, 15 to 100 mol%, more preferably 20 to 1
00 mol%.

The Mw of the alkali-soluble resin varies depending on the desired characteristics of the resist composition (b) or (c), but is preferably 1,000 to 150,000, more preferably 3,000 to 100,000. It is.

When the alkali-soluble resin has a repeating unit containing a carbon-carbon unsaturated bond, it can be used as a hydrogenated product. In this case, the hydrogenation rate is usually the number of carbon-carbon unsaturated bonds contained in the repeating unit.
It is at most 70%, preferably at most 50%, more preferably at most 40%. If the hydrogenation ratio exceeds 70%, the development characteristics of the alkali-soluble resin with an alkali developer tend to decrease.

In the resist compositions (b) and (c), the alkali-soluble resins can be used alone or in combination of two or more.

Dissolution Control Agent Next, the dissolution control agent used in the resist composition (b) has a property of controlling the alkali solubility of the alkali-soluble resin, and is decomposed in the presence of an acid, for example, hydrolyzed. Is a compound having an effect of reducing or eliminating the effect of controlling the alkali solubility of the alkali-soluble resin, or an effect of promoting the effect of controlling the alkali solubility of the alkali-soluble resin.

As such a dissolution controlling agent, for example, at least one substituent capable of dissociating into an acidic functional group such as a phenolic hydroxyl group and a carboxyl group in the presence of an acid (hereinafter referred to as “acid dissociable substituent”) ) Is introduced.

The acid-dissociable substituent is not particularly limited as long as it has the above-mentioned properties, and may be, for example, a substituted methyl group or a methyl group described in the section of the resin containing an acid-dissociable group.
Examples thereof include those similar to the acid dissociable groups such as a 1-substituted ethyl group, a silyl group, a 1-branched alkyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid dissociable group.

The dissolution controlling agent may be a low molecular weight compound or a high molecular weight compound. Preferred dissolution controlling agents are polyhydric phenol compounds such as bisphenol A, bisphenol F and bisphenol S, and carboxylic acid compounds such as hydroxyphenylacetic acid. And the like, in which the acid dissociable substituent is introduced.

The above-mentioned resin containing an acid-dissociable group can be used as a polymer dissolution controlling agent.

In the resist composition (b), the low-molecular compound and the high-molecular compound (that is, the resin having an acid-dissociable group) may be used alone or in combination of two or more. Alternatively, a low molecular compound and a high molecular compound can be used in combination.

An acid generator in the resist composition (b),
The mixing ratio of the alkali-soluble resin and the dissolution controlling agent is such that the acid generator is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 100 parts by weight of the alkali-soluble resin.
To 15 parts by weight, particularly preferably 0.5 to 10 parts by weight, and the dissolution controlling agent is preferably 5 to 150 parts by weight, more preferably 5 to 100 parts by weight, particularly preferably 5 to 50 parts by weight.
Parts by weight. If the amount of the acid generator is less than 0.05 parts by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by exposure, while if it exceeds 20 parts by weight, the resist composition (b) ) May cause uneven coating or scum may occur during development. If the amount of the dissolution controlling agent is less than 5 parts by weight,
It is difficult to obtain the desired effect based on the dissolution controlling agent, while 15
If the amount exceeds 0 parts by weight, the film forming property of the resist composition (b),
Film strength and the like tend to decrease.

Crosslinking Agent Next, a crosslinking agent capable of crosslinking an alkali-soluble resin in the presence of an acid used in the resist composition (C) is an acid,
For example, a compound capable of crosslinking an alkali-soluble resin in the presence of an acid generated by exposure. Such a crosslinking agent is not particularly limited as long as it has the above-mentioned action. For example, one or more substituents having a crosslinking reactivity with an alkali-soluble resin (hereinafter, referred to as “crosslinkable substituents”). ).

As the crosslinkable substituent, for example, (Where p is 1 or 2, and X is a single bond, -O-, -S-, -COO- or -N when p = 1.
H represents or a trivalent nitrogen atom when p = 2, Y represents -O- or -S-, m is an integer of 0 to 3, n is an integer of 1 to 3, m + n = 1 to 4. ) (Where Z represents —O—, —COO— or —CO—, and R ¹ and R ² may be the same or different from each other;
R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
Represents an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 14 carbon atoms, and k is an integer of 1 or more. ) ──C (R ⁴ ) = C (R ⁵ ) (R ⁶ ) (where R ⁴ , R ⁵ and R ⁶ may be the same or different from each other, and represent a hydrogen atom or an alkyl having 1 to 4 carbon atoms) Represents a group.) (Where R ¹ and R ² may be the same or different from each other, and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁷ and R ⁸ may be the same or different from each other;
It represents an alkylol group having 1 to 5 carbon atoms, and k is an integer of 1 or more. ) (Here, R ¹ and R ² may be the same or different from each other, and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁹ is a hetero atom of any of an oxygen atom, a sulfur atom and a nitrogen atom. And a divalent organic group forming a 3- to 8-membered ring, and k is an integer of 1 or more.)

Specific examples of such a crosslinkable substituent include a glycidyl ether group, a glycidyl ester group, a glycidylamino group, a methoxymethyl group, an ethoxymethyl group, a benzyloxymethyl group, a dimethylaminomethyl group, a diethylaminomethyl group, Examples include a dimethylolaminomethyl group, a diethylolaminomethyl group, a morpholinomethyl group, an acetoxymethyl group, a benzoyloxymethyl group, a formyl group, an acetyl group, a vinyl group, and an isopropenyl group.

Specific examples of the compound having a crosslinkable substituent include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolak resin epoxy compounds, resol resin epoxy compounds, poly (hydroxy styrene)
Epoxy compounds, methylol group-containing melamine compounds,
Benzoguanamine compound containing methylol group, urea compound containing methylol group, phenol compound containing methylol group, melamine compound containing alkoxyalkyl group, benzoguanamine compound containing alkoxyalkyl group, urea compound containing alkoxyalkyl group, phenol compound containing alkoxyalkyl group, phenol compound containing carboxymethyl group Examples include melamine compounds, carboxymethyl group-containing benzoguanamine compounds, carboxymethyl group-containing urea compounds, and carboxymethyl group-containing phenol compounds.

Among these compounds having a crosslinkable substituent, a phenol compound containing a methylol group, a melamine compound containing a methoxymethyl group, a phenol compound containing a methoxymethyl group, a phenol compound containing an acetoxymethyl group, and the like are more preferable. It is a melamine compound containing a methyl group. Commercially available methoxymethyl group-containing melamine compounds include CYMEL300, CYMEL
301, CYMEL303, CYMEL305 (trade name, manufactured by Mitsui Cyanamid) and the like.

As the cross-linking agent, a resin in which the above-mentioned cross-linkable substituent is introduced into an acidic functional group in an alkali-soluble resin to impart properties as a cross-linking agent is also suitable. In such a case, the introduction ratio of the crosslinkable functional group is usually 5 to 60 mol%, preferably 10 to 50 mol%, more preferably 15 to 40 mol%, based on all acidic functional groups in the alkali-soluble resin. Adjusted. When the introduction ratio of the crosslinkable functional group is less than 5 mol%, it is difficult to cause a sufficient crosslinking reaction,
When the residual film ratio is reduced, the meandering and swelling of the pattern are liable to occur, and when it exceeds 60 mol%, the alkali solubility of the alkali-soluble resin is reduced, and the developability tends to deteriorate.

In the resist composition (C), the crosslinking agents can be used alone or in combination of two or more. The compounding ratio of the acid generator, the alkali-soluble resin and the crosslinking agent in the resist composition (C) is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 20 parts by weight, per 100 parts by weight of the alkali-soluble resin. 1 to 15
Parts by weight, particularly preferably 0.5 to 10 parts by weight, and the crosslinking agent is preferably 5 to 95 parts by weight, more preferably 15 to 85 parts by weight, particularly preferably 20 to 75 parts by weight. If the amount of the acid generator is less than 0.05 part by weight, it may be difficult to effectively cause a chemical change due to the acid catalyst generated by exposure, while if it exceeds 20 parts by weight, the resist composition (c) ) May cause uneven coating or scum may occur during development. When the amount of the crosslinking agent is less than 5 parts by weight, the crosslinking reaction is usually insufficient, and the residual film ratio may decrease, the pattern may meander or swell, and if it exceeds 95 parts by weight, The scum increases and the developability tends to decrease.

Various additives such as a surfactant and a sensitizer can be added to the resist compositions (a) to (c) as required.

The surfactant has an effect of improving the coating properties and striation of the resist coating composition solution, the developability of the resist coating composition, and the like. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate,
In addition to polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Polyflow No.
75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo), F-top EF301, EF303, EF352 (manufactured by Shin-Akita Kasei), Megafax F171, F172, F173
(Made by Dainippon Ink), Florade FC430, FC43
1 (Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, S
C-103, SC-104, SC-105, SC-10
6 (made by Asahi Glass) and the like. These surfactants can be used alone or in combination of two or more. The amount of the surfactant is usually 2 parts by weight or less based on 100 parts by weight of all the resin components in the resist coating composition.

The sensitizer absorbs the energy of the radiation and transmits the energy to the acid generator, thereby increasing the amount of acid generated. It has the effect of improving the apparent sensitivity. The sensitizer to be used is not particularly limited as long as the sensitizer exerts the above-described actions and effects, but preferred specific examples thereof include acetone, benzene, acetophenones, benzophenones, naphthalenes, biacetyl, eosin, and rose. Bengal, pyrenes, anthracenes, phenothiazines and the like. These sensitizers can be used alone or in combination of two or more. The compounding amount of the sensitizer is usually 50 parts by weight or less, preferably 30 parts by weight or less based on 100 parts by weight of all the resin components in the resist coating composition.

The addition of a dye or a pigment can reduce the effect of halation at the time of exposure, and the addition of an adhesion aid can improve the adhesion to a substrate.

Further, other additives include antihalation agents such as azo compounds and amine compounds, storage stabilizers, defoamers, shape improvers and the like.

The solution of the resist coating composition of the present invention is, for example, a solution having a solid content of 5 to 50% by weight, for example, having a pore size of 0.1%.
It is prepared by filtering through a filter of about 2 μm.

Examples of the solvent used for preparing the resist coating composition solution include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol diether. Propyl ether, diethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene,
Xylene, methyl ethyl ketone, cyclohexanone, 2
-Heptanone, 3-heptanone, 4-heptanone, 2-
Ethyl hydroxypropionate, 2-hydroxy-2-
Ethyl methyl propionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3
-Methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, propyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, 3-methoxypropionic acid Examples thereof include methyl, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, N-methylpyrrolidone, N, N-dimethylformamide, and N, N-dimethylacetamide. These solvents are used alone or in combination of two or more.

Further, if necessary, benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-octanol,
Nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate,
γ-butyrolactone, ethylene carbonate, propylene carbonate,
One or more solvents having a high boiling point such as phenyl cellosolve acetate may be added.

The most significant feature of the present invention lies in that the metal content in the solution of the resist coating composition comprising the resist compositions (a) to (c) is appropriately controlled. According to the present invention, in addition to Na, K, Cu, Fe, etc., Li, Be, Mg, Ca, Zn, Al, Si, as metals contained as impurities in the resist coating composition solution.
Sn, Pb, Cr, Mn, Co, Ni and the like have been found. Of these metal impurities, which metal is contained in the resist coating composition solution and to what extent depends, of course, on the quality of the constituents, the level of process control when preparing the composition solution, and the like. Depending on these, these metals affect the catalytic ability of the acid generated upon exposure by remaining in the composition solution in various charge numbers or in the form of compounds. However, as shown in Table 1 and FIG.
Below the level of 00 ppb, the required increase curve of the exposure amount becomes gentle. That is, there is an inflection point between the total content of metals in the composition solution and the sensitivity at a point where the total content of metals is approximately 200 ppb, and the total content of metals in the resist coating composition solution is By controlling the amount to 200 ppb or less, not only can the decrease in sensitivity be practically suppressed, but also a stable sensitivity can be achieved.

The total content of metals in the resist coating composition solution is determined by, for example, adding resin components such as an acid-dissociable group-containing resin and an alkali-soluble resin to acetone, dioxane, tetrahydrofuran, methanol, ethanol, N-methylpyrrolidone, dimethyl After dissolving in a suitable solvent such as formamide and dimethyl sulfoxide, the solution is dropped into pure water,
By repeating the purification operation of drying the precipitated resin component overnight (preferably 5 times or more), the total content of metals can be reduced to a sufficient level of 200 ppb or less. However, in practice, the purity of the resist coating composition solution is naturally limited, and the purification limit of the above-described treatment by dissolution and precipitation is about 10 ppb as the total metal content. Conventionally, for resist coating composition solutions, no attempt has been made to quantitatively study the relationship between the total content of metal impurities and the sensitivity of the resist coating composition, and the facts clarified in the present invention are, for the first time, It is the knowledge of.

According to the present invention, metal impurities in the resist coating composition solution are mainly derived from the resin component used, and therefore, by subjecting the resin component to an appropriate purification operation, It is possible to reduce the total content of metals in the resist coating composition solution to almost a predetermined level. However, metal impurities can be caused by compounding components other than the resin component, additives, and the like, and after preparation of a desired resist coating composition solution,
Since there is a possibility that metal impurities may be mixed in for some reason, it is preferable that after preparing the resist coating composition solution, an appropriate purification operation be performed on the entire composition solution.

When a resist pattern is formed using the resist coating composition solution of the present invention, a protective film is provided on the resist film in order to prevent the influence of basic impurities and the like contained in the working atmosphere. You can also.

When forming a resist pattern from the resist coating composition solution of the present invention, the composition solution was coated with, for example, a silicon wafer or aluminum by means of spin coating, casting coating, roll coating or the like. A resist film is formed by applying the resist film on a substrate such as a wafer, and the resist film is exposed through a predetermined mask pattern. Radiation that can be used at that time is preferably far ultraviolet rays such as an excimer laser, but depending on the type of acid generator, X-rays such as synchrotron radiation and charged particle beams such as electron beams may be used. it can. Exposure conditions such as radiation dose are appropriately selected according to the composition of the resist coating composition, the type of additive, and the like.

In the present invention, it is preferable to perform post-exposure baking in order to improve the apparent sensitivity of the resist film. The heating conditions vary depending on the composition of the resist coating composition, types of additives, and the like.
00 ° C, preferably 50 to 150 ° C.

Thereafter, a predetermined resist pattern is formed by developing with an alkali developing solution. Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine,
Triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8
-Diazabicyclo- [5,4,0] -7-undecene,
An alkaline aqueous solution in which an alkaline compound such as 1,5-diazabicyclo- [4,3,0] -5-nonene is dissolved in a concentration of usually 1 to 10% by weight, preferably 2 to 5% by weight is used. Is done.

Further, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant can be added to the developer. When using a developer composed of an alkaline aqueous solution as described above, generally,
After development, it is washed with water.

[0072]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. However, the present invention is not limited to these Examples unless it exceeds the gist thereof. Synthesis Example 1 Poly (hydroxystyrene) (300 parts by weight) was dissolved in tetrahydrofuran, and triethylamine (130 parts by weight) was added. Then, at 0 ° C., 200 parts by weight of di-tert-butyl carbonate was added dropwise at 0 ° C., and the mixture was reacted for 6 hours. I let it. Thereafter, the reaction solution was dropped into pure water, and the precipitated resin was heated at 50 ° C.
In a vacuum oven kept overnight. As a result of NMR measurement, the obtained resin had a structure in which 25% of hydrogen atoms of a phenolic hydroxyl group were substituted with a t-butoxycarbonyl group. This resin is referred to as a resin (A-1). Next, 100 parts by weight of the resin (A-1) was dissolved in 700 parts by weight of acetone, dropped into 800 parts by weight of distilled water, and the precipitated resin was dried overnight in a vacuum dryer kept at 50 ° C. . Let the obtained resin be resin (A-2).
Further, 100 parts by weight of the resin (A-2) was mixed with acetone 700.
A purification operation of dissolving the resin in a weight part, dropping it into 800 parts by weight of distilled water, and drying the precipitated resin overnight in a vacuum dryer kept at 50 ° C. was repeated five times. The resin obtained after each of these purification operations was designated as resin (A-3) and resin (A-
4), resin (A-5), resin (A-6), resin (A-
7).

Examples 1 to 3 and Comparative Examples 1 to 4 Resins (A-1), (A-2) and (A-
3), (A-4), (A-5), (A-6) or (A
-7) 100 parts by weight and 1 part by weight of triphenylsulfonium trifluoromethanesulfonate are dissolved in 400 parts by weight of methyl 3-methoxypropionate, and the obtained solution is filtered through a membrane filter having a pore size of 0.2 μm to remove foreign substances. It was removed and a composition solution was prepared. Next, the obtained composition solution is spin-coated with a spinner on a silicon wafer at a rotation speed at which the film thickness after firing before exposure is 1 μm, and then fired at 100 ° C. for 2 minutes to form a resist film. Formed. A KrF excimer laser irradiation device (M
(BK-400TL-N) and exposed through a mask pattern. Thereafter, baking after exposure at 100 ° C. for 2 minutes, development using a 2% by weight aqueous solution of tetramethylammonium hydroxide at 25 ° C. for 1 minute, followed by pure water
After washing for 0 second, a resist pattern was formed. The evaluation results are shown in Table 1 and FIG.

In each of the examples and comparative examples, the metal content and the sensitivity were measured as described below. The metal content of each composition solution was measured using an atomic absorption spectrometer manufactured by Hitachi, Ltd.

Sensitivity When a resist pattern was formed from each composition solution, the exposure amount when a resist pattern having a line width of 0.5 μm was obtained according to the dimensions of the mask pattern was defined as the sensitivity.

[0076]

[Table 1]

[0077]

The resist coating composition solution of the present invention always exhibits a stable resist sensitivity by properly controlling the total content of metals in the solution. Moreover, the resist coating composition solution of the present invention is useful for fine processing using various radiations such as far ultraviolet rays such as excimer laser.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the metal content of a resist coating composition solution and sensitivity.

Continuation of the front page (56) References JP-A-63-126502 (JP, A) JP-A-59-176303 (JP, A) JP-A-5-234878 (JP, A) JP-A-5-234877 (JP) , A) Table 7-504762 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03F 7/004 G03F 7/038 G03F 7/039

Claims (1)

(57) [Claims] 1. A resist coating for forming a resist pattern by containing a component that generates an acid upon irradiation with radiation, and changing the solubility of the irradiated portion in a developing solution by a chemical reaction catalyzed by the acid. In a solution of the composition, the resist coating composition is as follows:
A resist coating composition solution comprising the composition (a), (b) or (c), wherein the total content of metals in the solution is 200 ppb or less in terms of a simple substance. (B) (1) Components that generate acid upon irradiation
(However, excluding diazoketone compounds), and (2)
Alkali insoluble or alkali protected by acid dissociable group
A poorly soluble resin, when the acid dissociable group is dissociated
Positive radiation sensitivity containing alkali-soluble resin
A resin composition, (b) (1) a component that generates an acid upon irradiation with radiation,
(2) an alkali-soluble resin, and (3) the alkali-soluble resin.
It has the property of controlling the alkali solubility of a soluble resin,
Decomposed in the presence of the alkali-soluble resin
Reduce or eliminate or enhance solubility control effect
Positive radiation containing dissolution controlling agent
A linear resin composition, (c) (1) a component that generates an acid upon irradiation with radiation,
(2) in the presence of an alkali-soluble resin and (3) an acid
Neither contains a crosslinking agent capable of crosslinking the alkali-soluble resin.
G-shaped radiation-sensitive resin composition.