JPH08211600A - Positive type resist composition - Google Patents

Abstract

PURPOSE: To obtain a resist compsn. excellent in performance such as gamma value. CONSTITUTION: This resist compsn. contains alkali-soluble polyphenol represented by formula I, an alkali-soluble polyhydroxy compd. represented by formula II, alkali-soluble novolak resin and a 1,2-quinonediazido compd. In the formula I, each of R and1 -R6 is H, 1-6C alkyl, etc., R7 is 1-6C alkyl, etc., and each of (m) and (n) is an integer of 1-3. In the formula II, R8 is H, etc., each of R9 -R11 is 1-6C alkyl, etc., each of (a)-(f) is an integer of 0-3 and at least two among (b), (d) and (f) are integers of 1-3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition sensitive to radiation such as ultraviolet rays and deep ultraviolet rays (including excimer laser, etc.).
The present invention relates to a positive resist composition suitable for producing an integrated circuit of 64 Mbit DRAM.

[0002]

2. Description of the Related Art A positive type photosensitive composition for the purpose of producing a photosensitive lithographic printing plate and a photoresist, which is capable of improving sensitivity without degrading performance such as development stability, For example, JP-A 1-280748 discloses a 1,2-quinonediazide compound, an alkali-soluble resin and the following general formula

[0003]

[Chemical 4]

(Wherein R ¹ , R ¹ ', R ² and R ² ' are the same or different and each represents a hydrogen atom, a halogen atom or a group such as an alkyl group, and R ³ is a hydrogen atom or a carbon atom of 1 to 4). A positive-type photosensitive composition characterized by containing a compound represented by the formula (1), wherein n ⁰ represents 0 or an integer of 1 to 4).

[0005]

However, the above-mentioned positive-type photosensitive composition is apt to cause necking, and is not always satisfactory from the viewpoint of profile (pattern shape).

[0006]

The inventors of the present invention excel in various performances such as profile, γ value, sensitivity and resolution, and especially
As a result of diligent studies to provide a positive resist composition suitable for producing an integrated circuit of 64 Mbit DRAM, a positive resist composition containing an alkali-soluble novolac resin and a 1,2-quinonediazide compound as essential components Furthermore, they have found that a composition containing a specific combination of alkali-soluble polyphenols and alkali-soluble polyhydroxy compounds is effective, and completed the present invention. That is, the present invention has the general formula (I)

[0007]

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(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R _{1 to} R ₆ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms. Or an alkenyl group having 2 to 6 carbon atoms, R ₇ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and m and n each independently represent an integer of 1 to 3). Alkali-soluble polyphenols represented by the general formula (II)

[0009]

[Chemical 6]

(In the formula, R ₈ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R ₉
To R ₁₁ each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a carboxyl group or a halogen atom, and a to f each independently represent an integer of 0 to 3. , B, d, and f represent an integer of 1 to 3. The present invention provides a positive resist composition containing an alkali-soluble polyhydroxy compound, an alkali-soluble novolak resin, and a 1,2-quinonediazide compound represented by the formula (1).

In the general formula (I), R and R _{1 to} R ₆
Is preferably a hydrogen atom or a methyl group, and m and n are preferably 1 or 2. R ₇ has 1 to 6 carbon atoms
Is preferred, and a methyl group and an ethyl group are particularly preferred. The alkali-soluble polyphenols represented by the general formula (I) include the following general formula

[0012]

[Chemical 7]

A compound represented by the formula (wherein R, R _{1 to} R ₆ , m and n have the same meanings as described above, and R ₁₂ represents an alkyl group having 1 to 6 carbon atoms) is preferable, and more preferable. Examples of the alkali-soluble polyphenols include

[0014]

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[0015]

[Chemical 9]

And the like.

The alkali-soluble polyphenols represented by the general formula (I) are, for example, the general formula (Ia)

[0018]

[Chemical 10]

Reaction of phenol and phosphorus oxychloride represented by the formula (wherein R _{1 to} R ₃ and m have the same meanings as described above) in amides such as N, N-dimethylformamide (Vilsmeier). Reaction), and after reacting the obtained reaction mixture with sodium cyanide, the reaction mixture is hydrolyzed in the presence of an acid or an alkali to give a compound of the general formula (Ib).

[0020]

[Chemical 11]

A mandelic acid derivative represented by the formula (wherein R, R _{1 to} R ₃ and m have the same meanings as described above),
Then, the mandelic acid derivative and the general formula (Ic)

[0022]

[Chemical 12]

(Wherein R _{4 to} R ₆ and n have the same meanings as described above) is condensed with a phenol represented by, for example, an acidic catalyst such as hydrochloric acid, and if necessary, obtained. The obtained product and an alcohol represented by the general formula (Id) R ₁₂ —OH (Id) (wherein R ₁₂ has the same meaning as described above) are added to an acidic substance such as p-toluenesulfonic acid. It can be produced by reacting in the presence.

The alkali-soluble polyhydroxy compound represented by the general formula (II) is a known compound described in the general formula [I] and the general formula [II] in JP-A-4-301850. Preferred alkali-soluble polyhydroxy compounds represented by the general formula (II) include, for example:

[0025]

[Chemical 13]

And the like.

The mixing ratio of the alkali-soluble polyphenols represented by the general formula (I) and the alkali-soluble polyhydroxy compound represented by the general formula (II) is usually 10:90 to 50:50 by weight, Preferably 15: 85-40: 60
Is.

The 1,2-quinonediazide compound is preferably a 1,2-naphthoquinonediazide compound, and the 1,2-naphthoquinonediazide compound is, for example, a compound having three or more phenolic hydroxyl groups and a 1,2-naphthoquinonediazide compound. -5- (or -4-) sulfonic acid chloride,
For example, 1,2-naphthoquinonediazide-5- (or-4 obtained by reacting in the presence of a deoxidizing agent such as triethylamine
-) Sulfonic acid ester and the like can be mentioned. These 1,2-
The quinonediazide compounds may be used alone or in combination of two or more. Examples of the compound having three or more phenolic hydroxyl groups include compounds described by the general formula on page 3 of JP-A-2-103543 and compounds represented by the general formula (I) or (II) in JP-A-2-32352. Described compounds, JP-A-2-2693
Compounds described by the general formula (I) in JP-A-51-
Examples thereof include compounds described by the formula on page 4 of 50851 and oxyflavans containing the compound described by formula (I) in JP-A-3-185447.

As the alkali-soluble novolac resin,
For example, phenol, o-cresol, p-cresol,
m-cresol, 3,5-xylenol, 2,5-xylenol, 2,3-xylenol, 3,4-xylenol, 2,3,5-tolumethylphenol, 4-tert-butylphenol, 2-
tert-butylphenol, 3-tert-butylphenol, 2-tert-butyl-4-methylphenol, 6-te
rt-Butyl-3-methylphenol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 4-tert-butylcatechol, 4-methoxyphenol, 3-methoxyphenol, 2-methoxyphenol, 2-methoxycatechol , 2-methoxyresorcinol, 3-methoxyresorcinol, 2,3-dimethoxyphenol, 2,5-dimethoxyphenol, 3,5-dimethoxyphenol, 3-ethylphenol, 2-ethylphenol, 4-ethylphenol, 2,3 , 5-Triethylphenol, 3,5-diethylphenol, 2,5-diethylphenol, 2-naphthol, 1,3-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, and the following general formula

[0030]

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(In the formula, R _{13 to} R ₁₈ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ₁₉ is a hydrogen atom or 1 to 4 carbon atoms. 4 represents an alkyl group or a phenyl group, and x, y and z each independently represent an integer of 0 to 2, but x + y + z> 2. 1 or 2 kinds of phenols such as phenol. Above, for example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde,
Isobutyraldehyde, n-hexylaldehyde, acrolein, crotonaldehyde, cyclohexanaldehyde, furfural, furylacrolein, benzaldehyde, o-tolualdehyde, p-tolualdehyde, m
-Tolualdehyde, p-ethylbenzaldehyde, 2,4-
Dimethylbenzaldehyde, 2,5-dimethylbenzaldehyde, 3,4-dimethylbenzaldehyde, 3,5-dimethylbenzaldehyde, phenylacetaldehyde, o-hydroxybenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, cinnamic aldehyde, o-anisaldehyde , P-anisaldehyde,
One or more aldehydes such as m-anisaldehyde and vanillin are condensed in the presence of one or more acid catalysts such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, acetic acid and oxalic acid. The resin obtained by the above is mentioned. The reaction temperature for condensation is usually 60 to 120 ° C, and the reaction time is usually 2 to
30 hours. Alkali-soluble novolac resin obtained by condensation has a GPC pattern area ratio (detector: UV254nm) in the range of polystyrene-reduced molecular weight of 1000 or less by means of fractionation etc. The area is preferably adjusted to 30% or less (more preferably 25% or less). For fractionation, the alkali-soluble novolac resin obtained by condensation is dissolved in a good solvent (for example, alcohols such as methanol, ketones such as acetone and methyl isobutyl ketone, ethers such as tetrahydrofuran), and then the obtained solution is dissolved. A method of pouring into water for precipitation, or the above solution is n-
It is carried out by a method of pouring into a poor solvent such as pentane, n-hexane and n-heptane for liquid separation.

The preferred amount of the 1,2-quinonediazide compound used is 10 to 50% by weight based on the total solid content of the positive resist composition.
The preferable total amount of the alkali-soluble polyphenols represented by the general formula (I) and the alkali-soluble polyhydroxy compound represented by the general formula (II) is 3 to 40% by weight based on the total solid content of the positive resist composition. %.

It is preferable that the solvent used for preparing the positive resist solution has an appropriate drying rate and the solvent evaporates to give a uniform and smooth coating film. As such a solvent,
For example, glycol ether esters such as ethyl cellosolve acetate and propylene glycol monomethyl ether acetate, solvents described in JP-A-2-220056, esters such as ethyl pyruvate, n-amyl acetate and ethyl lactate, 2-heptanone, γ. -Butyrolactone and other ketones. These solvents may be used alone or in combination of two or more.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” indicates “parts by weight”.

Synthesis Example 1 A mixture of 16.8 g of 4-hydroxymandelic acid, 37.6 g of phenol and 170 g of 10% hydrochloric acid was reacted at 60 to 65 ° C. for 2 hours. After the reaction was completed, 300 ml of deionized water and 300 m of acetone
The mixture of 1 was added and liquid separation was performed at 60 ° C. The obtained organic layer was washed with ion-exchanged water. The organic layer after washing was concentrated under reduced pressure, and the obtained concentration residue was mixed with 5 g of acetone and 8 g of toluene.
Recrystallized from 0 g of mixed solution

[0036]

[Chemical 15]

A compound represented by 16g of this compound
A mixture of 1.6 g of p-toluenesulfonic acid and 160 g of methanol was reacted at 65 ° C. for 2 hours. The reaction mixture was concentrated under reduced pressure, and a mixture of 200 ml of toluene, 200 ml of acetone and 400 ml of ion-exchanged water was added to the obtained concentrated residue and the layers were separated. The obtained organic layer was added with 0.5% sodium hydrogen carbonate 40
It was washed with 0 ml. Then, it was washed with ion-exchanged water. The organic layer after washing was concentrated under reduced pressure, and the obtained concentrated residue was recrystallized from a mixed solution of 21 g of toluene and 62 g of hexane. The crystals obtained were washed with hexane and then 40 ° C at 45 ° C.
Dry for hours

[0038]

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An alkali-soluble polyphenol represented by the formula (hereinafter referred to as compound a) was obtained. Melting point: 156-158 ° C FD-MS: m / e = 258

Synthesis Example 2 m-cresol 133.2 g, p-cresol 118.0 g, methyl isobutyl ketone 250 g, 11% oxalic acid 37.0 g and 90% acetic acid 85
135.9 g of 37% formalin in a mixture of g with stirring
Was added dropwise at 95 ° C. over 1 hour. After the dropping, at the same temperature
Reacted for 15 hours. The reaction mixture was washed with water and dehydrated to obtain a methyl isobutyl ketone solution of novolak resin. The polystyrene reduced weight average molecular weight by GPC was 4571.
Methyl isobutyl ketone solution of the above novolak resin (resin content 40%) 100 g, methyl isobutyl ketone 188.
After stirring 7 g and n-heptane 199.4 g at 60 ° C for 30 minutes, the mixture was allowed to stand,
The layers were separated. After adding 120 g of 2-heptanone to the obtained lower layer, it concentrated under pressure reduction conditions and the 2-heptanone solution of the novolak resin was obtained. The polystyrene-equivalent weight average molecular weight by GPC is 9540, and the area ratio of polystyrene-equivalent molecular weight 6000 or less to the total pattern area excluding the pattern area of unreacted phenols in the GPC pattern is 37.5%. Is 18.1%
Met.

Example 1 and Comparative Example 1 Resin (Novolak resin having a weight average molecular weight of 9540 obtained in Synthesis Example 2), 1,2-quinonediazide compound (photosensitizer A in Table 1), Compound a (obtained in Synthesis Example 1) Alkali-soluble polyphenols) and the formula below

[0042]

[Chemical 17]

Compound b (alkali-soluble polyhydroxy compound) represented by the following formula (1) was mixed and dissolved in the composition shown in Table 1 so that 50 parts of 2-heptanone was mixed. The resulting solution was filtered with a Teflon filter having a pore size of 0.2 μm to prepare a resist solution. The above resist solution was applied to a silicon wafer washed by a conventional method so as to have a film thickness of 1.1 μm using a spin coater, and baked at 90 ° C. for 1 minute on a hot plate. Then, the silicon wafer after baking is subjected to 365 nm (i
The exposure amount was changed stepwise by using a reduction projection exposure device (NSR1755i7A NA = 0.5, manufactured by Nikon Corporation) having an exposure wavelength of (line). The exposed silicon wafer was developed with an alkaline developer SOPD [Sumitomo Chemical Co., Ltd. product] for 1 minute to obtain a positive pattern. Resolution is 0.50 μm
The dimension of the smallest line-and-space pattern that can be separated without film loss at the exposure amount (effective sensitivity) at which the line-and-space pattern becomes 1: 1 was evaluated by a scanning electron microscope. Also, in a line and space of 50 μm, the abscissa plots the logarithm of the exposure dose, and the ordinate plots the residual film thickness of the exposed portion. The angle between the linear portion of 5000 to 1000 angstrom on the ordinate and the abscissa is plotted. Is defined as α, and its tan α is obtained and defined as a γ value. Regarding the heat resistance, the temperature at which a 3 μm line-and-space pattern started to deform when the patterned silicon wafer was heated for 3 minutes on a direct hot plate was determined. As for the profile, the cross-sectional shape of the 0.50 μm line-and-space pattern at the effective sensitivity was observed with a scanning electron microscope.

[0044]

[Table 1]

In Table 1, the photosensitizer A is 1,2-naphthoquinonediazide-5-sulfonic acid chloride and has the following formula.

[0046]

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It is a reaction product (reaction molar ratio is 2.5: 1) with the compound having three phenolic hydroxyl groups shown by.

[0048]

The positive resist composition of the present invention is particularly excellent in performances such as γ value, sensitivity and profile.
It is suitable for manufacturing an integrated circuit of 64 Mbit DRAM.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Ando 3-98 Kasugadeka, Konohana-ku, Osaka-shi, Osaka Sumitomo Chemical Co., Ltd.

Claims (2)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R _{1 to} R ₆ are each independently a hydrogen atom and _{1 to 6} carbon atoms.
6 alkyl group, an alkoxy group or an alkenyl group having 2 to 6 carbon atoms having 1 to 6 carbon atoms, R ₇ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m and n are each independently It represents an integer of 1 to 3. ) Alkali-soluble polyphenols represented by the general formula (II) (In the formula, R ₈ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R _{9 to} R ₁₁ each independently represent an alkyl group having 1 to 6 carbon atoms or a carbon atom. Represents an alkoxy group, a carboxyl group or a halogen atom of the formulas 1 to 6,
Each of a to f independently represents an integer of 0 to 3, and at least two of b, d and f represent an integer of 1 to 3. (4) An alkali-soluble polyhydroxy compound, an alkali-soluble novolac resin, and a 1,2-quinonediazide compound represented by the formula (1). 2. An alkali-soluble polyphenol represented by the general formula (I) is represented by the following general formula: (Wherein R, R _{1 to} R ₆ , m and n have the meanings described in claim 1, and R ₁₂ represents an alkyl group having 1 to 6 carbon atoms). The positive resist composition as described in 1.