JP3232641B2 - Radiation-sensitive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive resin composition containing an alkali-soluble resin and useful as a resist for producing highly integrated integrated circuits.

[0002]

2. Description of the Related Art Conventionally, a positive resist has been widely used in the manufacture of integrated circuits because a resist pattern having a high resolution can be obtained. A positive resist capable of forming a pattern is desired. That is, in order to form a fine resist pattern with a positive resist, when the latent image formed by exposure is developed with a developing solution composed of an alkaline aqueous solution, the exposed portion is in contact with a substrate such as a wafer. It is necessary to develop the resist pattern quickly to the part (the bottom of the pattern). However, in the conventional positive resist, the line width of the resist pattern to be formed is 0.8 μm.
When it was finer than m, the developability and pattern shape were not sufficient. Further, in order to manufacture a highly integrated circuit, a resist which is faithful to the design dimension of the mask by reducing the difference between the design dimension of the mask and the dimension of the actual resist pattern, that is, a resist having high dimensional fidelity, is required. Although it is necessary, in general, the smaller the line width of the pattern, the larger the difference between the mask design dimension and the actual resist pattern dimension tends to be.
Satisfactory dimensional fidelity has not always been achieved. Furthermore, the conventional positive type resist, when defocused at the time of exposure by a stepper, pattern shape deformation, degraded developability, differences from the design line width, etc. become remarkable, and it cannot be said that focus tolerance is sufficient. Was.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel radiation-sensitive resin composition. More specifically, the present invention has good developability and excellent pattern shape. In particular, it is an object of the present invention to provide a radiation-sensitive resin composition having excellent dimensional fidelity and focus tolerance, which is useful as a resist for manufacturing a highly integrated circuit.

[0004]

According to the present invention, the object is to provide an alkali-soluble resin and the following general formula (1- a ):

Embedded image [In the general formula (1- a ), X ^{1 to} X ⁹ may be the same or different and may be a hydrogen atom, an alkyl group, an alkoxy group, or-
Shows the OH group, R ¹ and R ² represents an optionally hydrogen atom or an alkyl group which may be the same or different, R ³ represents a hydrogen atom, an alkyl group or an aryl group, n is the number of 5 or 6. However, at least one of X ^{1 to} X ⁴ and / or X ⁵ to
At least one of X ⁹ is - assumed to be an OH group. ] And a radiation-sensitive resin composition characterized by further containing a component having a 1,2-quinonediazide group , or an alkali-soluble resin;
The following general formula (1-b)

Embedded image [In the general formula (1-b), X ^{1 to} X ⁹ are the same or different.
A hydrogen atom, an alkyl group, an alkoxy group or-
An OD group (where D is a hydrogen atom or
An organic group having a non-diazide group. ) Shows, R ¹ your
And R ² may be the same or different, and
R ³ represents a hydrogen atom, an alkyl group or an aryl
And n is a number of 5 or 6. However, the X ¹ ~X ⁴
At least one of the at least one and / or X ⁵ to X ⁹
Is an organic group in which D has a 1,2-quinonediazide group
—OD group. Sensitive radiation characterized by containing a compound represented by]
This is achieved by the conductive resin composition .

Hereinafter, the present invention will be described in detail, which will clarify the purpose, structure and effect of the present invention. First, as the alkali-soluble resin used in the present invention, for example, novolak resin, resol resin, poly (vinylphenol) or its derivative, styrene-maleic acid copolymer, poly (vinylhydroxybenzoate), acrylic acid containing carboxyl group Resin,
A methacrylic acid-based resin containing a carboxyl group can be used.

[0006] Preferred alkali-soluble resins are novolak resins. A particularly preferred novolak resin has the following formula:

Embedded image (Here, m is an integer of 1 to 3.) The compound is obtained by polycondensing a phenol represented by the following formula with an aldehyde.

The phenols include, for example, o-cresol, m-cresol, p-cresol, 2,3-
Xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol and the like can be mentioned. Of these, o-cresol,
m-Cresol, p-cresol, 2,5-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol are preferred.

These phenols can be used alone or
Used in combination of more than one species. A particularly preferable combination is m-cresol / 3,5-xylenol / p-cresol = 95 to 20/5 to 80/0 to 7 by weight ratio.
5, and m-cresol / 2,3,5-trimethylphenol / p-cresol = 95-30 / 5-70 / 0
~ 65.

The aldehydes to be polycondensed with the phenols include, for example, formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxy Benzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde,
m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-
Methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural and the like are preferred, and among these, formaldehyde is particularly preferred.

When formaldehyde is used as the aldehyde, examples of the formaldehyde generating source include hemiformals such as formalin, trioxane, paraformaldehyde, methylhemiformal, ethylhemiformal, propylhemiformal, butylhemiformal and phenylhemiformal. be able to.
Of these, formalin and butyl hemiformal are particularly preferred.

The above aldehydes can be used alone or in combination of two or more. The amount of the aldehyde used is preferably 0.7 to 3 mol, more preferably 0.8 to 1.5 mol, per 1 mol of the phenol.

For the polycondensation of the phenols and aldehydes, an acidic catalyst is usually used. Examples of the acidic catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, and acetic acid. The amount of these acidic catalysts used is usually 1 × 10 ^{−5 to} 5 × ⁵ mol per 1 mol of phenols.
× 10 ^-1 mol.

In the polycondensation of a phenol and an aldehyde, water is usually used as a reaction medium. However, when the phenol used is not dissolved in an aqueous solution of the aldehyde and becomes non-uniform from the beginning of the reaction. Alternatively, a hydrophilic solvent can be used as a reaction medium. Examples of the hydrophilic solvent include alcohols such as methanol, ethanol, propanol and butanol, and cyclic ethers such as tetrahydrofuran and dioxane. The amount of the reaction medium used is usually 20 to 1,000 parts by weight per 100 parts by weight of the reaction raw material.

The temperature of the polycondensation between the phenols and the aldehydes is appropriately adjusted depending on the reactivity of the reaction raw materials, but is usually from 10 to 200 ° C.

The method of polycondensation of phenols and aldehydes includes a method in which phenols, aldehydes and a reaction catalyst are charged at once, and a method in which phenols and aldehydes are gradually added in the presence of a reaction catalyst during the reaction. And the like.

After completion of the polycondensation reaction, in order to remove unreacted raw materials, reaction catalyst, reaction medium and the like existing in the reaction system,
Generally, the temperature of the reaction system is raised to 130 to 230 ° C,
Volatiles are removed under reduced pressure, for example, under a pressure of about 20 to 50 mmHg, and the generated resin is recovered.

The alkali-soluble resin used in the present invention has a weight average molecular weight in terms of polystyrene (hereinafter referred to as “Mw”).
That. ) Can be appropriately selected from the range of the molecular weight of the alkali-soluble resin conventionally used in the radiation-sensitive resin composition, but is preferably from 2,000 to 20,000, more preferably from 3,000 to 20,000. 000-2
0000 (hereinafter, Mw is 3,000 to 20,000)
The alkali-soluble resin in the range of 00 is referred to as “resin (A)”). The molecular weight of the alkali-soluble resin is 2
When it exceeds 000, it may be difficult to uniformly apply the composition of the present invention on a substrate,
If it is less than 0, the heat resistance tends to decrease. When a high molecular weight alkali-soluble resin is desirable, the resin obtained by the polycondensation reaction is dissolved in a good solvent such as ethyl cellosolve acetate, dioxane, methanol, or ethyl acetate, and then water, n-hexane, n-heptane is dissolved. By mixing a poor solvent such as the above, and separating the precipitated resin from the solution layer, the fractionated high molecular weight alkali-soluble resin may be recovered.

Further, in the radiation-sensitive resin composition of the present invention, a phenol compound having a low molecular weight may be used in combination with an alkali-soluble resin, whereby the alkali solubility of the alkali-soluble resin is improved. The low molecular weight phenol compound is not particularly limited, but preferably has about 2 to 6 benzene rings. Specific examples thereof include a compound represented by the following formula.

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Embedded image [Here, a, b, and c are each an integer of 0 to 3 (excluding the case where all are 0), and x, y, and z
Is an integer of 0 to 3, respectively. The use amount of these low-molecular-weight phenol compounds is usually 50 parts by weight or less based on 100 parts by weight of the alkali-soluble resin.

In the present invention, especially when the resin (A) is used, a low molecular weight alkali-soluble novolak resin and / or an alkali-soluble resol resin (hereinafter, these are referred to as “resin (B)”) may be used in combination. it can.

The resin (B) is obtained by polycondensation of a phenol and an aldehyde. Examples of the phenol include those described above for the novolak resin of the alkali-soluble resin, and phenol, 1-
Other phenols such as naphthol and 2-naphthol can be used. As the aldehydes, those mentioned for the novolak resin can be used. The amount of the aldehyde used is usually 0.2 to 0.8 mol per 1 mol of the phenol. In the polycondensation reaction, an alkali catalyst can be used in addition to the acidic catalyst used for producing the novolak resin.

The Mw of the resin (B) is usually from 200 to 1,5.
00, preferably 300 to 1,000.

Specific examples of the resin (B) include phenol / formaldehyde condensed novolak resin, o-cresol / formaldehyde condensed novolak resin, m-cresol / formaldehyde condensed novolak resin, p-cresol / formaldehyde condensed novolak resin, and m-cresol. / P-cresol / formaldehyde condensed novolak resin.

The amount of the resin (B) is usually the same as that of the resin (A).
50 parts by weight or less for 100 parts by weight.

Next, in the compound represented by the general formula (1- a ), X ^{1 to} X ⁹ represent a hydrogen atom, an alkyl group, an alkoxy group or an —OH group which may be the same or different . one
In the compound represented by the general formula (1-b), X ^{1 to} X ⁹ are the same.
Hydrogen atom, alkyl group, alkoxy
Si group or -OD group (where D is a hydrogen atom or an organic group having a 1,2-quinonediazide group)
Wherein at least one of X ^{1 to} X ⁴ and / or X ⁵ to
At least one of X ⁹ is a compound wherein D is a 1,2-quinonediazide group.
It must be an organic group having an —OD group. General formula
In (1-a) and general formula (1-b), among X ^{1 to} X ⁹ , the alkyl group preferably has 4 or less carbon atoms, and examples thereof include a methyl group, an ethyl group, and n-propyl. Group, isopropyl group, n-butyl group, t-butyl group and the like. The alkoxy group preferably has 4 or less carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Further, among D 1 in the —OD group, examples of the organic group having a 1,2-quinonediazide group include 1,2-quinonediazide.
A 1,2-quinonediazidosulfonyl group such as a benzoquinonediazide-4-sulfonyl group, a 1,2-naphthoquinonediazide-4-sulfonyl group, and a 1,2-naphthoquinonediazide-5-sulfonyl group is preferred. Among them, a 1,2-naphthoquinonediazide-4-sulfonyl group and a 1,2-naphthoquinonediazide-5-sulfonyl group are particularly preferred. In addition, the general formula (1- a) or the general formula (1-
In the compound represented by b ), R ¹ and R ² represent a hydrogen atom or an alkyl group which may be the same or different, and examples of the alkyl group include the same as those in the case of X ^{1 to} X ⁹ Can be. R ³ represents a hydrogen atom, an alkyl group or an aryl group, and the alkyl group includes X ^{1 to} X ⁹
Examples of the aryl group include a phenyl group, a toluyl group, and a naphthyl group.

Specific examples of the compound represented by the general formula (1- a ) (hereinafter referred to as "compound (a)") include compounds represented by the following formula.

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The compound (a) can be produced, for example, by reacting a phenol with a benzylidenecycloalkanone in the presence of an acidic catalyst. As the phenols, resorcinol, catechol, hydroquinone, 2-methylresorcinol, methylhydroquinone, phloroglysinol, pyrogallol, hydroxyhydroquinone, and the like are preferable. Are preferred.

In the compound represented by the general formula (1- b ), a part or all of D is an organic group having a 1,2-quinonediazide group (hereinafter, referred to as "compound (b)"). Are 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2-naphthoquinonediazide-6-sulfonic acid ester, 2,1-
Naphthoquinonediazide-4-sulfonic acid ester, 2,
1-naphthoquinonediazide-5-sulfonic acid ester,
Examples thereof include 1,2-benzoquinonediazide-4-sulfonic acid ester. Among these, preferred compounds are 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester and the like.

The compound (b) is, for example, a compound (a)
And 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1,2-naphthoquinonediazide-5-sulfonyl chloride, and other 1,2-quinonediazidosulfonyl chlorides, etc., obtained by an esterification reaction in the presence of a basic catalyst. be able to. In this case, the reaction ratio between the compound (a) and 1,2-quinonediazidosulfonyl chloride is 0.2 to 1 mol of 1,2-quinonediazidosulfonyl chloride per 1 gram equivalent of the phenolic hydroxyl group of the compound (a). It is particularly preferred that the amount is 0.4 to 1.0 mol.

In the radiation-sensitive resin composition of the present invention, the compounds represented by formula (1-a) or (1-b ) are used alone or in combination of two or more. The amount used is usually 100 alkali-soluble resins.
5 to 50 parts by weight, especially 10 to 3 parts by weight
0 parts by weight is preferred. Thus, the general formula (1- a)
The compound represented by the general formula (1-b ) reduces the occurrence of scum during development and reduces the amount of undeveloped residue, resulting in excellent developability, pattern shape, dimensional fidelity, and focus tolerance. Is improved.

In the radiation-sensitive resin composition of the present invention,
When the compound (b) is not used, it is necessary to compound a compound having a 1,2-quinonediazide group other than the compound (b) (hereinafter, referred to as “compound (c)”).
Compound (c) includes 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester, 1,2-naphthoquinonediazide-6-sulfonic acid ester, 1,2-naphthoquinonediazide-6-sulfonic acid ester, Benzoquinonediazide-4-sulfonic acid ester and the like can be mentioned.

Specific examples of compound (c) include 2,3
4-trihydroxybenzophenone, 2,3,4,4 '
-Tetrahydroxybenzophenone, 3'-methoxy-
2,3,4,4'-tetrahydroxybenzophenone,
2,2 ', 5,5'-tetramethyl-2 ", 4,4'-
Trihydroxytriphenylmethane, 1,1,1-tris (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1- [4- { 1- (4-
Hydroxyphenyl) -1-methylethyl { -1-phenyl ] ethane, 2,4,4-trimethyl-2 ′, 4 ′,
1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5-sulfonic acid ester or 1,2-benzoquinonediazide of a phenolic hydroxyl group-containing compound such as 7-trihydroxy-2-phenylflavan. 4-sulfonic acid ester; a hydrogen atom of a hydroxyl group of the resin (B) is, for example, 0.2 to 1 mol, preferably 0.4 to 1 mol per gram equivalent of the hydrogen atom.
0 mol of 1,2-naphthoquinonediazide-5
Examples thereof include 1,2-quinonediazidosulfonic acid esters substituted with a sulfonyl group.

The compounding amount of the compound (c) in the radiation-sensitive resin composition of the present invention is preferably 100 parts by weight or less, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the alkali-soluble resin.

The total amount of the component having a 1,2-quinonediazide group, that is, the compound (b) and / or the compound (c) in the radiation-sensitive resin composition of the present invention depends on the development characteristics of the composition and the resist pattern. It is appropriately selected in consideration of the characteristics and the like, but is preferably 5 to 150 parts by weight, more preferably 1 to 100 parts by weight based on 100 parts by weight of the alkali-soluble resin.
0 to 80 parts by weight.

Further, the radiation-sensitive resin composition of the present invention may optionally contain various additives such as a sensitizer and a surfactant. The sensitizer improves the sensitivity of the resist to radiation. Examples thereof include 2H-pyrido- (3,2-b) -1,4-oxazin-3 (4H) -ones and 10H. -Pyrido- (3,2-
b) 1,4-benzothiazines, urazoles, hydantoins, parbituric acids, glycine anhydrides,
-Hydroxybenzotriazoles, alloxanes, maleimides and the like. The amount of these sensitizers is based on 100 parts by weight of the alkali-soluble resin.
Preferably it is 50 parts by weight or less.

The surfactant has an effect of improving the coating property and the developing property, and examples thereof include polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene octyl phenyl ether. In addition to nonionic surfactants such as ethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate,
KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) which is an organopolysiloxane polymer, and Polyflow No. which is an acrylic acid-based or methacrylic acid-based polymer. 75, no. 95
(Trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF3
01, EF303, EF352 (trade name, manufactured by Shin-Akita Kasei), Megafax F171, F172, F173
(Trade name, manufactured by Dainippon Ink), Florard FC430,
FC431 (trade name, manufactured by Sumitomo 3M), Asahigard AG710, Surflon S-382, SC-101,
SC-102, SC-103, SC-104, SC-1
05, SC-106 (trade name, manufactured by Asahi Glass) and the like. The amount of these surfactants is preferably 2 parts by weight or less based on 100 parts by weight of the solid content of the composition.

Further, the radiation-sensitive resin composition of the present invention may contain a dye or a pigment or an adhesion auxiliary agent. In the former case, the latent image of the radiation-irradiated portion is visualized and the halation at the time of radiation-irradiation is performed. Can be suppressed, and in the latter case, the adhesiveness can be improved. If necessary, a storage stabilizer, an antifoaming agent and the like can be added.

In forming a resist pattern using the radiation-sensitive resin composition of the present invention, an alkali-soluble resin, a compound (a), (b) or (c) and, if necessary, are blended. The various additives are dissolved in a solvent so that the solid content concentration becomes, for example, 20 to 40% by weight, and the solution is prepared as a solution by filtering through a filter having a pore size of about 0.2 μm. Therefore, the composition of the present invention comprises
In one embodiment, it means a composition comprising an alkali-soluble resin, compound (a), (b) or (c), and the above-mentioned various additives blended as required, and in another embodiment, It is to be understood that this means a solution of the above composition in a solvent.

Examples of the solvent used for preparing this solution include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and propylene glycol. Monomethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxy Ethyl acetate, ethyl hydroxyacetate, 2-
Methyl hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3
-Ethyl ethoxypropionate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate and the like. Further, these solvents include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl Ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol,
Benzyl alcohol, benzyl acetate, ethyl benzoate,
It can be used in combination with a high boiling point solvent such as diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and ethylene glycol monophenyl ether acetate.

The radiation-sensitive resin composition of the present invention prepared as a solution is applied to a substrate such as a silicon wafer or a wafer coated with aluminum or the like by a coating method such as spin coating, casting coating, roll coating or the like. Is applied to form a radiation-sensitive layer, irradiated with radiation through a predetermined mask pattern, and developed with a developer to form a pattern. When using the radiation-sensitive resin composition of the present invention as a positive resist, after application on a substrate, after pre-firing and irradiation, heat treatment at 70 to 140 ° C., By subsequently developing, the effect of the present invention can be further improved.

As the developer for the radiation-sensitive resin composition of the present invention, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, diamine -N-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo- [5,4,0]- 7-undecene, 1,5
- diazabicyclo - the 4,3,0] -5 Roh Ne alkaline compounds such emissions, concentration, aqueous alkaline solution is used which was dissolved in for example, 1 to 10 wt%. In addition, an appropriate amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol, or a surfactant may be added to the developer. When a developer composed of such an alkaline aqueous solution is used, it is generally washed with water after development.

[0041]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The measurement of Mw and various performance evaluations of the resist were performed by the following methods. Mw: GPC column manufactured by Tosoh Corporation (G2000H6: 2 columns, G3
000H6: 1 bottle, G4000H6: 1 bottle) under the conditions of a flow rate of 1.5 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C., and gel permeation chromatography using monodisperse polystyrene as a standard. Graph method (GP
C method). Dimensional fidelity: Nikon NSR-1505i6A reduction projection exposure machine (numerical aperture of the lens: 0.45) was used to change the exposure time and was exposed using i-rays having a wavelength of 365 nm, and then tetramethylammonium hydroxide was used. Using a 2.4% by weight aqueous solution, development was performed at 25 ° C. for 60 seconds, washed with water, and dried to form a resist pattern on the wafer. At this time, a case where the exposure time is such that a 0.6 μm line-and-space pattern is formed in a one-to-one width, and the mask dimension of the line-and-space pattern is reduced at 0.02 μm intervals. , Resist line
The difference between the AND space pattern dimension and the actual mask design dimension was measured with a scanning electron microscope. The difference between the pattern dimension and the mask design dimension is ± 1 of the mask design dimension.
A case of 0% or less was regarded as acceptable, and the minimum design dimension of the mask in the accepted pattern was defined as dimensional fidelity. The smaller the minimum design dimension of the mask, the better the dimensional fidelity. Focus tolerance: Using a scanning electron microscope, for a line-and-space pattern with a line width of 0.5 μm, the focus deviation when the pattern size to be resolved is within ± 10% of the mask design size. And the focus range. The larger the focus range, the better the focus tolerance. Developability: The degree of scum and residual development was examined by a scanning electron microscope. Pattern shape: A cross section of the developed resist pattern having a line width of 0.6 μm was observed using a scanning electron microscope. FIG. 1 schematically shows the cross-sectional shape of the resist pattern. FIG. 1 (G) shows a good shape, and both (A) and (B) show bad shapes.

[Synthesis of Resin (A)] Synthesis Example 1 In a flask equipped with a stirrer, a cooling pipe and a thermometer, m-
67.6 g (0.63 mol) of cresol, 31.8 g (0.29 mol) of p-cresol, 10.0 g (0.073 mol) of 2,3,5-trimethylphenol, 107.1 g of a 37% by weight aqueous formaldehyde solution (Formaldehyde: 1.32 mol) and oxalic acid dihydrate 1.33
g (0.0106 mol), the flask was immersed in an oil bath, and the temperature of the reaction solution was maintained at 100 ° C., and polycondensation was performed for 30 minutes with stirring. Thereafter, 17.5 g (0.16 mol) of m-cresol and 40.0 g (0.29 mol) of 2,3,5-trimethylphenol were added, and polycondensation was further performed for 40 minutes. Then, the temperature of the oil bath was raised to 180 ° C., and at the same time, the pressure in the flask was reduced to 30 to 50 mmHg to remove water, oxalic acid, unreacted raw materials and the like. Subsequently, the molten resin was recovered after cooling to room temperature. This resin was dissolved in ethyl cellosolve acetate so as to have a solid content of 20% by weight, twice the amount of methanol and the same amount of water were added to the weight of the resin solution, and the mixture was stirred and left. . The lower layer (resin solution) separated into two layers by standing was taken out, concentrated, dehydrated, and dried to recover the resin. This resin is referred to as a resin (A1).

Synthesis Example 2 Into an autoclave, 69.2 g (0.6 m-cresol) was added.
4 mol), 2,3,5-trimethylphenol 21.8
g (0.16 mol), 61.0 g of a 37% by weight aqueous solution of formaldehyde (formaldehyde: 0.75 mol), 6.3 g (0.05 mol) of oxalic acid dihydrate, and 52.6 of water
g and 182 g of dioxane were charged, and then the autoclave was immersed in an oil bath. The temperature of the reaction solution was maintained at 130 ° C., and polycondensation was carried out for 6 hours with stirring. After the reaction, the resultant was cooled to room temperature, and the contents were taken out into a beaker. The lower layer separated into two layers in the beaker was taken out, concentrated, dehydrated, and dried to recover the resin. This resin is referred to as a resin (A2).

Synthesis Example 3 In a flask similar to that used in Synthesis Example 1, 95.2 g (0.88 mol) of m-cresol, 24.4 g (0.18 mol) of 2,3,5-trimethylphenol, 154 g of a 37% by weight aqueous formaldehyde solution (formaldehyde: 1.90 mol) and 1.82 g of oxalic acid dihydrate
(0.014 mol), the flask was immersed in an oil bath, and the temperature of the reaction solution was maintained at 100 ° C., and polycondensation was performed for 90 minutes with stirring. Thereafter, 23.8 g (0.22 mol) of m-cresol and 97.6 g (0.72 mol) of 2,3,5-trimethylphenol were added,
Polycondensation was performed for another 60 minutes. Then, water, oxalic acid, unreacted raw materials, and the like were removed in the same manner as in Synthesis Example 1, and the resin was recovered by cooling. This resin was dissolved in ethyl cellosolve acetate so as to have a solid content of 20% by weight, and 1.8 times the amount of methanol and the same amount of water with respect to the weight of the resin solution were added, followed by stirring. I left it.
The lower layer (resin solution) separated into two layers by standing was taken out, concentrated, dehydrated, and dried to recover the resin. This resin is referred to as a resin (A3).

[Synthesis of Resin (B)] Synthesis Example 4 In a flask similar to that used in Synthesis Example 1, 64.8 g (0.60 mol) of m-cresol and p-cresol 4 were added.
3.2 g (0.40 mol), 24.3 g of a 37% by weight aqueous solution of formaldehyde (formaldehyde: 0.30 mol) and oxalic acid dihydrate 0.30 g (0.0024 mol)
Mol), and the flask was immersed in an oil bath. The temperature of the reaction solution was maintained at 100 ° C., and polycondensation was carried out for 40 minutes with stirring. Then, water, oxalic acid, unreacted raw materials, and the like were removed in the same manner as in Synthesis Example 1, and the resin was recovered by cooling. This resin is referred to as a resin (B1).

[Synthesis of Compound (b)] Here, (a-1) is a compound represented by the formula

Embedded image Wherein (a-2) is a compound represented by the formula

Embedded image It is a compound represented by these. Synthesis Example 5 In a flask equipped with a stirrer, a dropping funnel and a thermometer,
Under light shielding, 38.8 g (0.1 mol) of compound (a-1), 53.7 g (0.2 mol) of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and dioxane 2
50 g was charged and dissolved with stirring. Then, the flask was immersed in a water bath maintained at a temperature of 30 ° C. When the temperature of the reaction solution became constant at 30 ° C., 22.2 g (0.22 mol) of triethylamine was added to the solution, and the reaction solution temperature was lowered. Was gradually added using a dropping funnel so that the temperature did not exceed 35 ° C. Thereafter, the precipitated triethylamine hydrochloride was separated by filtration, and the filtrate was poured into a large amount of diluted hydrochloric acid to precipitate a product. The precipitated product was filtered and dried all day and night in a heated vacuum dryer maintained at 40 ° C. to give compound (b)
-1) was obtained.

Synthesis Example 6 Compound (a-2) 37.4 g (0.1 mol), 1,2-
Naphthoquinonediazide-5-sulfonic acid chloride 53.
7 g (0.2 mol) and 22.2 g of triethylamine
Compound (b-2) was obtained in the same manner as in Synthesis Example 5 except that (0.22 mol) was used.

[Synthesis of Compound (c)] Synthesis Example 7 10.0 g of resin (B1), 13.9 g of 1,2-naphthoquinonediazide-5-sulfonic acid chloride, dioxane 2
A quinonediazide compound (a) was obtained in the same manner as in Synthesis Example 5 except that 50 g and 5.75 g of triethylamine were used.

Synthesis Example 8 23.0 g of 2,3,4-trihydroxybenzophenone
(0.10 mol), 1,2-naphthoquinonediazide-5
-A quinonediazide compound (b) was obtained in the same manner as in Synthesis Example 5 except that 69.9 g (0.26 mol) of sulfonic acid chloride and 28.9 g (0.29 mol) of triethylamine were used.

Synthesis Example 9 2,3,4,4'-Tetrahydroxybenzophenone 2
4.6 g (0.10 mol), 1,2-naphthoquinonediazide-5-sulfonic acid chloride 107.5 g (0.40 mol)
Mol) and 44.5 g (0.44 mol) of triethylamine, to give a quinonediazide compound (c) in the same manner as in Synthesis Example 5.

Examples 1 to 6 and Comparative Examples 1 to 3 Resins (A), low molecular weight phenol compounds or resins (B) having the compositions shown in Table 1 (parts are parts by weight).
(*), The compound (a) or the compound (b) , the compound (c) and the solvent were mixed to form a uniform solution, which was then filtered through a membrane filter having a pore size of 0.2 μm to prepare a composition solution. The obtained solution is applied on a silicon wafer having a silicon oxide film using a spinner, and then pre-baked on a hot plate at 90 ° C. for 2 minutes to form a 1.2 μm thick resist film. Various performance evaluations of the resist were performed. Table 2 shows the evaluation results.

[0052]

[Table 1] In Table 1, the types of the low molecular weight phenol compound and the solvent are as follows. α: 1,1,1-tris (4-hydroxyphenyl)
Ethane β: 1,1-bis (4-hydroxyphenyl) -1-
Phenylethane S1: Ethylene glycol monoethyl ether acetate S2: Ethyl 2-hydroxypropionate S3: Methyl 3-methoxypropionate

[0053]

[Table 2] As is clear from Table 2, the resist formed from the radiation-sensitive resin composition of the present invention has extremely excellent dimensional fidelity and focus tolerance, and also has a good pattern shape. In addition, there was little scum and residual development, and the developability was excellent.

[0054]

As described in detail above, the radiation-sensitive resin composition of the present invention, as a resist, has remarkably excellent dimensional fidelity and focus tolerance, has a good pattern shape, and has good developability. Is also excellent.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross-sectional shape of a resist pattern.

Continuation of the front page (72) Inventor Takao Miura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-3-185447 (JP, A) JP-A-2-84650 (JP, A) JP-A-61-97278 (JP, A) JP-A-2-287545 (JP, A) JP-A-3-191351 (JP, A) JP-A-1-289947 (JP, A) JP-A-62-24241 (JP, A) JP-A-5-45869 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (2)

(57) [Claims] 1. An alkali-soluble resin and the following general formula (1- a ): [In the general formula (1- a ), X ^{1 to} X ⁹ may be the same or different and may be a hydrogen atom, an alkyl group, an alkoxy group, or-
Shows the OH group, R ¹ and R ² represents an optionally hydrogen atom or an alkyl group which may be the same or different, R ³ represents a hydrogen atom, an alkyl group or an aryl group, n is the number of 5 or 6. However, at least one of X ^{1 to} X ⁴ and / or X ⁵ to
At least one of X ⁹ is - assumed to be an OH group. ] The radiation-sensitive resin composition containing the compound represented by these, and further containing the component which has a 1,2- quinonediazide group. 2. An alkali-soluble resin and the following general formula:
(1-b) [In the general formula (1-b), X ^{1 to} X ⁹ are the same or different.
A hydrogen atom, an alkyl group, an alkoxy group or-
An OD group (where D is a hydrogen atom or
An organic group having a non-diazide group. ) Shows, R ¹ your
And R ² may be the same or different, and
R ³ represents a hydrogen atom, an alkyl group or an aryl
And n is a number of 5 or 6. However, the X ¹ ~X ⁴
At least one of the at least one and / or X ⁵ to X ⁹
Is an organic group in which D has a 1,2-quinonediazide group
—OD group. Sensitive radiation characterized by containing a compound represented by]
Resin composition.