JP3424369B2 - Positive resist composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition which is sensitive to radiation such as ultraviolet rays and far ultraviolet rays (including excimer lasers, etc.) 16 ~
The present invention relates to a positive resist composition suitable for producing a 64-Mbit DRAM integrated circuit. [0002] A positive type photosensitive composition for the production of a photosensitive lithographic printing plate and a photoresist, which can improve sensitivity without deteriorating performance such as development stability. For example, JP-A-1-280748 discloses a 1,2-quinonediazide compound, an alkali-soluble resin, and a compound represented by the following general formula: Wherein R ¹ , R ¹ ′, R ² and R ² ′ are the same or different and each represent a hydrogen atom, a halogen atom or an alkyl group; R ³ represents a hydrogen atom or a carbon atom; Wherein n ⁰ represents 0 or an integer of 1 to 4). [0005] However, the above-mentioned positive photosensitive composition tends to cause necking and is not always satisfactory from the viewpoint of profile (pattern shape). Means for Solving the Problems The present inventors are excellent in various properties such as profile, γ value, sensitivity and resolution.
As a result of intensive studies to provide a positive resist composition suitable for manufacturing integrated circuits of ~ 64 Mbit DRAM, a positive resist composition containing alkali-soluble novolak resin and 1,2-quinonediazide compound as essential components Further, they have found that a composition containing a specific combination of an alkali-soluble polyphenol and an alkali-soluble polyhydroxy compound is effective, and have completed the present invention. That is, the present invention relates to a compound represented by the general formula (I): (I) wherein R is a hydrogen atom or a C1-6
R _{1 to} R ₆ each independently represent a hydrogen atom
, An alkyl group having 1 to 6 carbon atoms, an alcohol having 1 to 6 carbon atoms
Represents an xy group or an alkenyl group having 2 to 6 carbon atoms, m and
n each independently represents an integer of 1 to 3; R ₁₂ has 1 carbon atom
Represents an alkyl group of 1 to 6. Alkali-soluble polyphenols represented by), the general formula (II) [0009] embedded image [0010] (wherein, R ₈ represents a hydrogen atom, an alkyl group or an aryl group having 6 to 10 carbon atoms having 1 to 6 carbon atoms, 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; a to f each independently represent an integer of 0 to 3; , B, d and f represent an integer of 1 to 3. A) a positive resist composition comprising an alkali-soluble polyhydroxy compound, an alkali-soluble novolak resin, and a 1,2-quinonediazide compound. 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 ₁₂ Has 1 carbon
To 6 alkyl groups , particularly preferably a methyl group and an ethyl group. As the alkali-soluble polyphenols represented by the formula (I), is rather preferable than [0012] For example [0013] embedded image Embedded image And the like. The alkali-soluble polyphenols represented by the general formula (I) include, for example, those represented by the general formula (Ia): Wherein R _{1 to} R ₃ and m have the same meanings as described above, and reacting the phenol and phosphorus oxychloride in an amide such as N, N-dimethylformamide (Vilsmeier). Reaction), and sodium cyanide is reacted with the obtained reaction mixture. Then, the reaction mixture is hydrolyzed in the presence of an acid or an alkali to give a compound of the general formula (Ib): (Wherein, R, R _{1 to} R ₃ and m have the same meaning as described above).
Then, the mandelic acid derivative and the general formula (Ic): (Wherein R _{4 to} R ₆ and n have the same meaning as described above) with phenol in the presence of an acidic catalyst such as hydrochloric acid. The resulting product and an alcohol represented by the general formula (Id) R ₁₂ —OH (Id) (wherein R ₁₂ has the same meaning as described above), for example, of 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, for example, a known compound represented by the general formulas (I) and (II) in JP-A-4-301850. Preferred alkali-soluble polyhydroxy compounds represented by the general formula (II) include, for example, 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 from 10:90 to 50:50 by weight, Preferably 15:85 to 40:60
It is. The 1,2-quinonediazide compound is preferably a 1,2-naphthoquinonediazide compound. Examples of the 1,2-naphthoquinonediazide compound include 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 esters and the like. These 1,2-
The quinonediazide compounds are used alone or as a mixture 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 of the general formula (I) or (II) described in JP-A-2-32352. Compound described, JP-A-2-2693
No. 51, a compound represented by the general formula (I);
Examples include compounds described by the formula on page 4 of 50851 and oxyflavans containing the compound described by the formula (I) in JP-A-3-185447. As the alkali-soluble novolak 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 [ Embedded image Wherein 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 represents a hydrogen atom, 1 to 4 carbon atoms. And x, y and z each independently represent an integer of 0 to 2, provided that x + y + z> 2.) With the above, for example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde,
Isobutyraldehyde, n-hexylaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, 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, cinnamaldehyde, o-anisaldehyde , P-anisaldehyde,
Condensation with one or more aldehydes such as m-anisaldehyde and vanillin in the presence of one or more acid catalysts such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, acetic acid and oxalic acid Resins obtained by the above method. The reaction temperature of the condensation is usually from 60 to 120 ° C, and the reaction time is usually from 2 to
30 hours. The alkali-soluble novolak resin obtained by condensation has a GPC pattern area ratio (detector: UV254 nm) in the range of polystyrene equivalent molecular weight of 1000 or less using a method such as fractionation. It is preferably adjusted to 30% or less (more preferably 25% or less) based on the area. The fractionation is performed by dissolving the alkali-soluble novolak resin obtained by condensation in a good solvent (for example, alcohols such as methanol, ketones such as acetone and methyl isobutyl ketone, and ethers such as tetrahydrofuran). A method of precipitation by pouring into water, or n-
It is performed by a method of pouring into a poor solvent such as pentane, n-hexane and n-heptane and separating the solution. The preferred amount of the 1,2-quinonediazide compound is 10 to 50% by weight based on the total solids 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. %. The solvent used for the preparation of the positive resist solution preferably has an appropriate drying rate and gives a uniform and smooth coating film by evaporation of the solvent. Such solvents include:
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; And ketones such as butyrolactone. These solvents are used alone or in combination of two or more. EXAMPLES Hereinafter, the present invention will be described specifically 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 completion of the reaction, 300 ml of ion-exchanged water and 300 m of acetone
l of the mixture was added, and the mixture was separated at 60 ° C. The obtained organic layer was washed with ion exchanged water. The washed organic layer was concentrated under reduced pressure, and the resulting residue was concentrated in 5 g of acetone and 8 g of toluene.
Recrystallizing from 0 g of the mixture, the following formula was obtained. The compound represented by the following formula was obtained. 16g of this compound
, 1.6 g of p-toluenesulfonic acid and 160 g of methanol were 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 to carry out liquid separation. The obtained organic layer is washed with 0.5% sodium hydrogen carbonate 40
Washed with 0 ml. Next, it was washed with ion-exchanged water. The organic layer after washing was concentrated under reduced pressure, and the resulting concentrated residue was recrystallized from a mixture of 21 g of toluene and 62 g of hexane. The obtained crystals are further washed with hexane, and then
After drying for a time, the following formula: An alkali-soluble polyphenol represented by the following formula (hereinafter referred to as compound a) was obtained. Melting point: 156 DEG-158 DEG C. FD-MS: m / e = 258 Synthesis Example 2 133.2 g of m-cresol, 118.0 g of p-cresol, 250 g of methyl isobutyl ketone, 37.0 g of 11% oxalic acid and 85% of 90% acetic acid
135.9 g of 37% formalin in the mixture of
Was added dropwise at 95 ° C. over 1 hour. After dropping, at the same temperature
The reaction was performed for 15 hours. The reaction mixture was washed with water and dehydrated to obtain a solution of novolak resin in methyl isobutyl ketone. The weight average molecular weight in terms of polystyrene by GPC was 4,571.
100 g of the above novolak resin in a methyl isobutyl ketone solution (resin content is 40%), and methyl isobutyl ketone 188.
After stirring 7 g and 199.4 g of n-heptane at 60 ° C. for 30 minutes, the mixture was allowed to stand,
Separated. After 120 g of 2-heptanone was added to the obtained lower layer, the mixture was concentrated under reduced pressure to obtain a 2-heptanone solution of a novolak resin. The polystyrene equivalent weight average molecular weight by GPC is 9540, and the area ratio of polystyrene equivalent molecular weight of 6000 or less to the total pattern area excluding the unreacted phenols pattern area in the GPC pattern is 37.5%, and the area ratio of polystyrene equivalent molecular weight of 1000 or less 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 (photosensitive agent A in Table 1), compound a (obtained in Synthesis Example 1) Alkali-soluble polyphenol) and the following formula: Compound (b) (alkali-soluble polyhydroxy compound) represented by the following formula (1) was mixed and dissolved so that 50 parts of 2-heptanone was obtained in the composition shown in Table 1. The resulting solution 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 silicon wafer washed by a conventional method so as to have a thickness of 1.1 μm using a spin coater, and baked on a hot plate at 90 ° C. for 1 minute. Next, the silicon wafer after baking was filled with 365 nm (i.
(NSR1755i7ANA = 0.5) having an exposure wavelength of (line), the exposure amount was changed stepwise to perform exposure. The exposed silicon wafer was developed with an alkali developing solution SOPD (manufactured by Sumitomo Chemical Co., Ltd.) for 1 minute to obtain a positive pattern. Resolution is 0.50μm
The dimension of the minimum line and space pattern that can be separated without reducing the film at an exposure amount (effective sensitivity) at which the line and space pattern becomes 1: 1 was evaluated with a scanning electron microscope. Also, in a 50 μm line and space, the logarithm of the exposure amount is plotted on the horizontal axis, and the remaining film thickness of the exposed portion is plotted on the vertical axis, and the angle between the linear portion of 5000 to 1000 angstroms on the vertical axis and the horizontal axis Is defined as α, and its tan α is determined to obtain a γ value. With respect to heat resistance, a temperature at which a line and space pattern of 3 μm starts to be deformed when a patterned silicon wafer is heated on a direct hot plate for 3 minutes. 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. [Table 1] In Table 1, the photosensitive agent A is 1,2-naphthoquinonediazide-5-sulfonic acid chloride and the following formula: Is a reaction product with a compound having three phenolic hydroxyl groups (reaction molar ratio: 2.5: 1). The positive resist composition of the present invention is particularly excellent in performance such as γ value, sensitivity and profile.
It is suitable for manufacturing integrated circuits of up to 64 Mbit DRAM.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Nobuo Ando, Inventor, Sumitomo Chemical Co., Ltd. 3-1-198 Kasuganaka, Konohana-ku, Osaka-shi, Osaka (56) Reference JP-A-3-142468 (JP, A JP-A-2-273641 (JP, A) JP-A-5-346665 (JP, A) JP-A-1-280748 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/00-7/42

Claims (1)

(57) [Claims] [Claim 1] The general formula (I) ... (I) (wherein, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms )
R _{1 to} R ₆ each independently represent a hydrogen atom, a carbon number of 1 to
6 alkyl groups, alkoxy groups having 1 to 6 carbon atoms or carbon
Represents an alkenyl group of Formulas 2 to 6, wherein m and n are each independently
Represents an integer of 1 to 3. R ₁₂ is an alkyl having 1 to 6 carbon atoms
Represents a group. Alkali-soluble polyphenols represented by), the general formula (II) ## STR2 ## (Wherein, 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, Represents an alkoxy group of 1 to 6, a carboxyl group or a halogen atom,
a to f each independently represent an integer of 0 to 3, but at least two of b, d, and f represent an integer of 1 to 3. A positive resist composition comprising an alkali-soluble polyhydroxy compound, an alkali-soluble novolak resin, and a 1,2-quinonediazide compound represented by the formula (1).