JP3265684B2 - Positive resist composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a positive resist composition used for semiconductor integrated circuits and the like.

[0002] In recent years, integrated circuits have been miniaturized with higher integration, and submicron pattern formation has been required. As a result, the positive resist composition is required to have more excellent properties such as sensitivity, resolution, and profile. However, in general, sensitivity is reduced when trying to improve the resolution and profile, and development residue (scum) is generated when trying to increase the sensitivity without lowering the resolution. Thus, it has been difficult to achieve both sensitivity, resolution, and profile.

[0003]

SUMMARY OF THE INVENTION The present invention provides a positive resist composition which is excellent in balance among various properties such as sensitivity, resolution and profile and has no scum.

[0004]

According to the present invention, there is provided a compound of the general formula
(I) and two kinds of the general formula (II) or (III)
Quinonediazidesulfonic acid esters of phenolic compounds
Or a mixture of the general formula (II) or (III), and the general formula
Quinonedia of two phenolic compounds represented by (IV)
Mixture of didosulfonic acid esters

[0005]

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Wherein R _{1 to} R ₄₂ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyl group;
₄₃ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ) And an alkali-soluble resin.

The quinonediazidesulfonic acid ester is produced by reacting a phenol compound represented by any one of the general formulas (I) to (IV) with a quinonediazidesulfonic acid halide in an organic solvent in the presence of a basic catalyst. Examples of the organic solvent include dioxane, tetrahydrofuran, acetone, dichloromethane, chloroform, and γ-butyrolactone. Examples of the basic catalyst include an organic base such as triethylamine and a weak base such as an inorganic alkali such as sodium hydrogen carbonate. Examples of the quinonediazidesulfonic acid halide include 1,2-benzoquinonediazide-4-sulfonic acid chloride and 1,2-naphthoquinonediazide-4- or -5-sulfonic acid chloride. The phenol compounds represented by the general formulas (I), (II) and (IV) are known and have the general formula (III)
The phenol compound represented by the formula (1) is produced by the method described in Japanese Patent Application No. 5-22772. The pair combined quinonediazide sulfonic acid esters, mixtures of general formula (I), and quinone diazide sulfonic acid ester of the general formula (II) or two kinds of phenol compound represented by (III);
Alternatively, it is a mixture of quinonediazidesulfonic acid esters of two phenol compounds represented by the general formula (II) or (III) and the general formula (IV). The esterification rate of the phenol compound is adjusted by the reaction molar ratio as desired. The preferable addition amount of each of the above-mentioned esters is 5 to 95% by weight based on all the esters. A more preferred addition amount is 10 to 90% by weight based on the total ester.

Examples of the alkali-soluble resin include novolak resins obtained by condensing phenols and aldehydes. Examples of the phenols include phenol, cresol, xylenol, ethylphenol, trimethylphenol, propylphenol, and the like. Butylphenol, dihydroxybenzene, naphthols and the like. These phenols can be used alone or
Used as a mixture of more than one species.

Examples of the aldehyde include formaldehyde and paraformaldehyde. The condensation of phenols and aldehydes is carried out in the presence or absence of a solvent by a conventional method using a catalyst. Examples of the catalyst include inorganic acids (such as hydrochloric acid, sulfuric acid, and phosphoric acid) and organic acids (such as oxalic acid, formic acid, and p-toluenesulfonic acid).
Or a divalent metal salt (such as zinc acetate or magnesium acetate). The condensation reaction conditions are usually from 60 to 120.
C. for 2 to 30 hours.

The preparation of the positive resist solution is carried out by mixing the quinonediazide sulfonic acid ester and an alkali-soluble resin (the weight ratio of both is preferably in the range of 1: 1 to 6: 1) with a solvent. Examples of the solvent include ethyl cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether acetate, butyl acetate, methyl isobutyl ketone, 2-heptanone, and xylene. For example, an alkali-soluble compound having a molecular weight of less than 900 may be added to the positive resist solution.
No. 5955, compounds represented by the general formula (I), JP-A-4-50851, compounds represented by the general formula (I), or JP-A-3-17953, a compound represented by the general formula (I) And the like. The preferred addition amount of the above compound is 3 to 3 in the total solid content of the positive resist composition.
40% by weight.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the text, parts indicate parts by weight. Examples (1-3) and Comparative Examples (5-10) Alkali-soluble resins (abbreviated as resin in the table below), quinonediazide sulfonic acid esters (abbreviated as photosensitizer in the table below) and additives are shown in the following table. Was mixed with 50 parts of 2-heptanone, and the resulting mixture was filtered through a Teflon filter having a pore size of 0.2 μm to prepare a resist solution. The resist solution was applied to a thickness of 1.1 μm on a silicon wafer that had been washed by a conventional method using a spin coater, and baked on a hot plate at 90 ° C. for 1 minute. Then, at 365 nm (i
Exposure was performed using a reduction projection exposure machine (Nikon Corporation, NSR1755i7A NA = 0.5) having an exposure wavelength of (line), with the exposure amount being changed stepwise. Next, the wafer was baked on a hot plate at 110 ° C. for 1 minute. This was developed with SOPD (developer; product of Sumitomo Chemical Co., Ltd.) for 1 minute to obtain a positive pattern. The resolution was an exposure amount (effective sensitivity) at which a 0.5 μm line-and-space pattern became 1: 1. The dimensions of the line-and-space pattern to be separated without film loss were evaluated by a scanning electron microscope. As for the profile, the cross-sectional shape of a 0.5 μm line-and-space pattern at the effective sensitivity was observed with a scanning electron microscope. Regarding the scum, the presence or absence of scum between the lines of the 0.5 μm line and space pattern in the effective sensitivity was observed with a scanning electron microscope.

[0012]

[Table 1]

[0013]

[Table 2]

Additive: a compound represented by the following formula:

[0015]

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Resin: m-cresol / p-cresol /
Novolak resin obtained by condensation under reflux conditions using oxalic acid as a catalyst at formalin = 0.5 / 0.5 / 0.7 (molar ratio) [Molecular weight 60
The area ratio of the components having a molecular weight of 1000 or less and the components having a molecular weight of 1000 or less are respectively
A resin having 37.5% and 18.1% (excluding the pattern of unreacted phenols) and having a weight average molecular weight in terms of polystyrene of 9000. ]

Photosensitizer: A reaction product of a phenol compound represented by the following formulas A 'to F' and 1,2-naphthoquinonediazide-5-sulfonic acid chloride [in (), a reaction molar ratio].

[0018]

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[0019]

The positive resist composition of the present invention has a sensitivity,
Excellent balance of various performance such as resolution and profile,
And there is no scum.

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Hirotoshi Nakanishi 3-1-1, Kasuganaka, Konohana-ku, Osaka-shi, Osaka Inside Sumitomo Chemical Co., Ltd. Naka 3-chome No. 98 Sumitomo Chemical Co., Ltd. (56) References JP-A-4-295472 (JP, A) JP-A-4-241353 (JP, A) JP-A-2-84650 (JP, A) JP-A-4-177353 (JP, A) JP-A-3-185447 (JP, A) JP-A-4-293050 (JP, A) JP-A-4-301850 (JP, A) JP-A-4-301 301847 (JP, A) JP-A-4-284454 (JP, A) JP-A-4-328555 (JP, A) JP-A-4-29242 (JP, A) JP-A-6-236030 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (1)

(57) [Claims] (1) The compound represented by the general formula (I) and the general formula (II) or (II)
Quinonediazides of the two phenolic compounds represented by I)
A mixture of sulfonic acid esters; or a general formula (II) or
(III) and two kinds of phenols represented by the general formula (IV)
Mixture of quinonediazide sulfonic acid esters of compounds (Wherein, R _{1 to} R ₄₂ each independently represent a hydrogen atom,
R ₄₃ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ) And an alkali-soluble resin.