JPH0284648A - Positive type radiation sensitive resin composition - Google Patents

Abstract

PURPOSE:To prevent the wear of film of the subject composition even in case the composition is processed by using a radiant ray having a short wavelength, and to obtain a good resist pattern with high resolution by incorporating a specified alkali soluble resin, a radiation sensitive compd. and a compd. capable of suppressing dissolution against an alkaline aqueous solution in the composition. CONSTITUTION:The alkali soluble resin capable of forming a film which has a dissolving speed to an aqueous solution contg. 1wt.% of tetramethyl ammonium hydroxide at 25 deg.C of <=10,000 A/min, at least one kind of the radiation sensitive compd. selected from a group comprising diazo ketone and diazosulfone, and the compd. capable of suppressing the dissolution to the alkaline aqueous solution of the alkali soluble resin are incorporated in the composition. Thus, in case the composition is processed by using the radiant ray having the short wavelength such as a far UV ray or an excimer laser, etc., the wear of film of the composition in an unirradiated part at the time of developing it with the alkaline aqueous solution is reduced, and the resist pattern with good profile and the high resolution is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Industrial Application Field The present invention relates to a positive radiation-sensitive resin composition. The present invention relates to a positive radiation-sensitive resin composition suitable as a resist for producing densified integrated circuits.

b. Prior Art In recent years, as the density of semiconductor integrated circuits has increased, their processing dimensions have become increasingly finer, and it has become necessary to form submicron resist patterns. In order to form such submicron resist patterns, instead of the conventional reduction projection technology that uses G-line (=436 nm), which is ultraviolet light emitted from an ultra-high pressure mercury lamp, as a radiation source, far ultraviolet rays, excimer laser, etc. are used. , a technique for improving resolution using short-wavelength radiation with a wavelength of 200 to 400 ni has been proposed and is viewed as promising.

C8 Problems to be Solved by the Invention When using short-wavelength radiation such as deep ultraviolet rays and excimer lasers as described above, it is difficult to use conventional alkali-soluble resins and 1
, 2-quinonediazide compound as a main component, the absorption of radiation on the resist surface is too large, so the radiation does not reach the inside of the resist, and as a result, development with a developer consisting of an alkaline aqueous solution is difficult. The drawback is that the profile of the resist pattern obtained by the method is poor.

As an alternative to 1,2-quinonediazide compounds in such positive resists, Japanese Patent Application Laid-Open No. 56-1933
The issue describes compounds sensitive to radiation in the short wavelength region of 300 na or less, such as 2゜2-dimethyl-4,6-thiketo-5-diazo-1゜3-dioxane (hereinafter referred to as diazomeldrum's acid). Disclosed. but,
Since diazomeldrum's acid has a poor ability to suppress dissolution in an alkaline aqueous solution used as a developer, development causes significant film loss in areas that have not been irradiated with radiation, making it difficult to obtain a good resist pattern.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to prevent film loss in areas not irradiated with radiation during development with an alkaline aqueous solution even when short wavelength radiation such as deep ultraviolet rays or excimer laser is used as a radiation source. An object of the present invention is to provide a positive radiation-sensitive resin composition capable of obtaining a resist pattern with a good profile at high resolution.

Means for solving problems d and il The positive radiation-sensitive resin composition of the present invention can form a film having a dissolution rate of 10,0 OOA/min or less in a tetramethylammonium hydroxide/wt% aqueous solution at 25°C. Containing an alkali-soluble resin, at least one radiation-sensitive compound selected from diazoketones and diazosulfones, and a compound having a function of suppressing dissolution of the alkali-soluble resin in an alkaline aqueous solution (hereinafter referred to as an alkali dissolution inhibiting compound). It is characterized by:

Examples of the radiation-sensitive compounds used in the present invention, diazoketones and diazosulfones, include the compounds shown below.

Bl (here, R1 and R2 are hydrogen atoms; alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups; phenyl, tolyl, and xylyl groups) , a biphenyl group, an aryl group having 6 to 20 carbon atoms such as a naphthyl group, or cyclopropane,
It represents a cycloalkyl group having 3 to 20 carbon atoms such as cyclobutane, cyclopentane, and cyclohexane, and may be the same or different. ) group; cyano group: phenyl group; tolyl group; methoxyphenyl group; phenyl chloride group; nitrated phenyl group; cyanide phenyl group; or 1 carbon number such as methoxy group, ethoxy group, cyclohexyloxy group, benzyloxy group ~10
represents an alkoxy group, which may be the same or different. ) (Here, R5 is the same as R1 and R2) Furthermore, the alkali dissolution inhibiting compound used in the present invention is preferably at least one compound selected from sulfonic acid esters, sulfones, and ketones, such as the following: Examples include compounds having an aromatic ring.

FL!几9 (Here, R3 and R4 are methyl groups; Amino (here, R6, R7, Re, R9, R10 and R11 are hydrogen atoms; halogen atoms; hydroxyl group; vinyl group; allyl group niamino group; cyano group: Nitro group; methyl group, ethyl group,
Alkyl groups with 1 to 10 carbon atoms such as propyl, butyl, pentyl, hexyl; methoxy, ethoxy, cyclohexyl, benzyloxy, phenoxy, triloxy, naphthyloxy, anthryloxy, etc. alkoxy group having 1 to 14 carbon atoms; phenyl group,
Noryl group, naphthyl group, anthryl group, where R+2 is a hydrogen atom: a halogen atom; a hydroxyl group; a vinyl group: an allyl group; an amino group; a cyano group: a nitro group; an alkyl group having 1 to 10 carbon atoms as described above; Alkoxy group having 1 to 14 carbon atoms; same carbon as above. ), which may be the same or different, provided that R6, R7, R8, R9, RIG, and R11 Further, alkaline dissolution inhibiting compounds other than the above include, for example, tetraethylthiuram disulfide,
Thiurams such as tetramethylthiuram monosulfide, thioureas such as N,N'-diphenylthiourea;
Thioketones such as thiobenzophenone; and toluenesulfonyldiethylamide, toluenesulfonyldiphenylamide, toluenesulfonyldipropylamide,
Examples include sulfonamides in which hydrogen is not bonded to the nitrogen atom of the sulfonamide structure, such as toluenesulfonylpyrrolidine, toluenesulfonylpiperidine, and bistoluenesulfonylpiperazine.

The total amount of the radiation-sensitive compound and alkali dissolution inhibiting compound used in the present invention is 100% of the alkali-soluble resin.
The amount is usually 5 to 10 parts by weight, preferably 10 to 50 parts by weight. If this amount is less than 5 parts by weight, it will be difficult to form a resist pattern.
On the other hand, if the amount exceeds 100 parts by weight, all of the added radiation-sensitive compound cannot be sensitized by short-term radiation irradiation, making development with a developer consisting of an alkaline aqueous solution difficult.

Further, the compounding ratio of the radiation-sensitive compound and the alkali dissolution-inhibiting compound is usually 1 to 300 parts by weight, preferably 5 to 100 parts by weight, particularly preferably 1 to 300 parts by weight, and particularly preferably 20-100
Parts by weight. If the amount of the alkali dissolution inhibiting compound added is less than 1 part by weight, the film loss in the non-irradiated areas after development will be large, making it difficult to form a good resist pattern.
On the other hand, if it exceeds 300 parts by weight, development with a developer consisting of an alkaline aqueous solution becomes difficult.

The alkali-soluble resin used in the present invention is capable of forming a film having a dissolution rate of 10,000 A/min or less in a 1% by weight aqueous solution of tetramethylammonium hydroxide at 25°C. If an alkali-soluble resin with a dissolution rate exceeding 10,000 A/min is used, the effect of the alkali dissolution-inhibiting compound in the present invention cannot be exhibited.
It becomes difficult to obtain a good resist pattern.

A typical example of the alkali-soluble resin used in the present invention is an alkali-soluble novolak resin (hereinafter referred to as novolak resin). Novolac resins are obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst.

Examples of phenols include phenol, 0-
Cresol, m-cresol, p-cresol, 0-ethylphenol, m-ethylphenol, p-ethylphenol, 0-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol, 2
, 4-xylenol, 2,5-xylenol, 3,4-
Xylenol, 3,5-xylenol, 2,3.5-trimethylphenol, p-phenylphenol, hydroquinone, catechol, resorcinol, 2-methylresorcinol, pyrogallol, α-naphthol, bisphenol A1 dihydroxybenzoate, gallic acid ester, etc. Among these phenols, phenol, 0-cresol, m-cresol, p-cresol, 2゜5-xylenol, 3,5-xylenol, 2゜3.5-trimethylphenol, resorcinol, 2-methyl Resorcinol and bisphenol A are preferred. These phenols may be used alone or in combination of two or more.

Examples of aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, 0-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, 0-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde,
0-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, 0-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, p-
n-Butylbenzaldehyde and the like are used, and among these compounds formaldehyde, acetaldehyde and benzaldehyde are preferred. These aldehydes may be used alone or in combination of two or more.

The aldehyde is preferably used in a proportion of 0.7 to 3 mol, particularly preferably 0.7 to 2 mol, per mol of phenol.

As the acid catalyst, for example, inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, or organic acids such as formic acid, oxalic acid, and acetic acid are used.

The amount of these acid catalysts used is preferably 1 x 10-4 to 5 x 10'' moles per mole of phenol.

In the polycondensation of phenols and aldehydes, water is usually used as the reaction medium, but if the phenols are not dissolved in the aqueous solution of aldehydes, a hydrophilic solvent can also be used as the reaction medium. Examples of these hydrophilic solvents include alcohols such as methanol, ethanol, propatool, and butanol; and cyclic ethers such as tetrahydrofuran and dioxane. The amount of these reaction media used is usually 20 to 1000 parts by weight per 100 parts by weight of the reaction raw materials. The reaction temperature of the condensation reaction can be adjusted as appropriate depending on the reactivity of the reaction raw materials, but is usually 10 to 200°C, preferably 70 to 150°C.

After the condensation reaction is completed, the unreacted raw materials, acid catalyst, and reaction medium present in the system are removed to recover the novolac resin.

Examples of alkali-soluble resins other than novolac resins used in the present invention include polyhydroxystyrene or derivatives thereof, styrene-maleic anhydride copolymers, polyvinylhydroxybenzoate, carboxyl group-containing methacrylic resins, and the like.

These alkali-soluble resins may be used alone or in combination of two or more.

A sensitizer can be added to the composition of the present invention in order to improve the sensitivity as a resist.

As a sensitizer, for example, 2H-pyrido(3,2-b>-
1,4-oxazin-3(4H)ones, 10H-pyrido(3,2-b)(1,4)-benzothiazines, wauzols, hydantoins, barbylic acids, glycine anhydrides, 1-hydroxybenzo Examples include triazoles, alloxanes, and maleimides.

The amount of the sensitizer to be blended is usually 100 parts by weight or less per 100 parts by weight of the radiation-sensitive compound.

Furthermore, the composition of the present invention may contain a surfactant in order to improve the coating properties, for example, the striae and the developability of the radiation irradiated area after forming a dry coating film. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; Oxyethylene alkyl phenyl ethers; and polyethylene glycol dilaurate,
Nonionic surfactants of polyethylene glycol dialkyl esters such as polyethylene glycol distearate; FTOP EF301, EF303, EF35
2 (manufactured by Shinju Kasei ■), Megafac F171, F1
72, F173 (manufactured by Dainippon Ink ■), Florado F
C430, FC431 (manufactured by Sumitomo 3M ■), Asahi Guard AG710, Surflon S-382, 5C101
,5C102,5C103,'3C104,5C105
, 5C106 (manufactured by Asahi Glass); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical); acrylic acid-based or methacrylic acid-based (co-)
Polymer Polyflow No., 75, No. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo ■), etc. are used. The blending amount of the surfactant is usually 2 parts by weight or less per 100 parts by weight of the total amount of the alkali-soluble resin and radiation-sensitive compound.

Further, the composition of the present invention may optionally contain an antihalation agent, an adhesion aid, a storage stabilizer, an antifoaming agent, and the like.

The composition of the present invention is prepared by dissolving the above-mentioned alkali-soluble resin, radiation-sensitive compound, alkali dissolution-inhibiting compound, and various above-mentioned ingredients in a solvent in predetermined amounts.
It can be prepared by filtering with a filter of about 100 ml.

Solvents used in this case include, for example, ethylene glycol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether,
Diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether; ethylene glycol alkyl acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol alkyl ether acetate such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol propyl ether acetate Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone and cyclohexanone; Methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate,
-Ethyl hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, 2-hydroxy-3
-Methyl butanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-
Esters such as methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutylbutyrate, ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate; Amides such as dimethylformamide and dimethylacetamide are used. be able to.

In addition, benzylethyl ether, dihexyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1
-octatool, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate,
High boiling solvents such as diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate, etc. can also be added.

These solvents may be used alone or in combination of two or more.

As a method for applying the composition of the present invention to a substrate such as a silicon wafer, the composition of the present invention is dissolved in the above-mentioned solvent so that the solid content concentration is, for example, 5 to 50% by weight, and then treated with P. Examples of coating methods include spin coating, flow coating, and roll coating.

Examples of the developer for the composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia;
Secondary amines such as diethylamine and di-n-propylamine; Tertiary amines such as triethylamine and methyldiethylamine Alcohol amines such as dimethylethanolamine and triethanolamine; Tetramethylammonium hydroxide , tetraethylammonium hydroxide, quaternary ammonium hydroxide such as 2-hydroxyethyltrimethylammonium hydroxide; pyrrole, piperidine, 1.8
-diazabicyclo(5,4,0)-7-undecene, 1
．． An alkaline aqueous solution prepared by dissolving a cyclic amine such as 5-diazabicyclo(4,3,0)-5-notyne can be used.

Furthermore, an alkaline aqueous solution prepared by appropriately adding a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol, or a surfactant to the developer can also be used as the developer.

After developing with the developer, the film is rinsed with water and dried.

e. Examples The present invention will be explained in more detail by Examples below.
The present invention is not limited to these.

Example 1 (1) In a flask, 501 g of m-cresol and p-
After charging 50 g of cresol, 66 ml of a 37% by weight formaldehyde aqueous solution and 0.04 g of oxalic acid were added,
The flask was immersed in an oil bath while stirring, the reaction temperature was maintained at 100° C., and polycondensation was carried out for 6 hours to obtain a novolac resin. After the reaction, the inside of the system was adjusted to 30 mmHg.
The pressure was reduced to remove water, and the internal temperature was further raised to 130°C to distill off unreacted substances. The dissolved novolac resin was then returned to room temperature and collected.

+2) 20 g of novolak resin obtained in (1) 1 2 g of diazomeldrum acid, 2 g of p-toluenesulfonic acid phenol ester and 9 ethyl cellosolve acetate
After stirring and dissolving 6g at room temperature, the pore size was 0.2μm.
A solution of the composition of the present invention was prepared by filtration using a membrane filter.

This solution was applied onto a silicon wafer using a spinner, and then bre-baked at 90°C for 2 minutes to form a 0.5 μm layer.
A resist layer with a film thickness of .

Next, using a 2.4% by weight aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMA) as a developer, development was performed for a certain period of time, and the resist film reduction rate was evaluated, and it was found to be 0.047 μm/min. , the membrane did not decrease at all.

Next, a far ultraviolet contact exposure machine (Canon PLA)
521F), a 120 m
Irradiate far ultraviolet rays of J/cJ, 7MA2.4ffffff
It was developed with a 1% aqueous solution for 1 minute, rinsed with water, and dried. When the obtained resist pattern was observed with a scanning electron microscope, it was found that a 0.6 μm line-and-space positive type pattern could be resolved.

Comparative Example 1 A resist composition solution was prepared in the same manner as in Example 1 using 20 g of the novolak resin obtained in Example 1 (1), 96 g of diazomeldrum acid 11- and ethyl cellosolve acetate. Next, the resist film thinning rate was evaluated in the same manner as in Example 1, and was found to be 2.7 μm/min. In addition, as in Example 1, far ultraviolet rays were irradiated through a pattern mask using a far ultraviolet contact exposure machine, and TMAl
Although development was attempted with a 2% aqueous solution, it was difficult to form a pattern because the areas not irradiated with deep ultraviolet rays were significantly dissolved.

Examples 2 to 6 100 parts by weight of the novolak resin obtained in Example 1 (1) were dissolved in ethyl cellosolve acetate at predetermined ratios of the radiation-sensitive compound and the alkali dissolution inhibiting compound shown in Table 1, and the solid content concentration was A 16.7% by weight solution of the composition of the invention was prepared. Next, the resist film reduction rate was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained.

In addition, in the same manner as in Example 1, far ultraviolet rays were irradiated through a pattern mask using a far ultraviolet contact exposure machine at the far ultraviolet irradiation amount shown in Table 1.
It was developed with an aqueous solution for 1 minute, rinsed with water, and dried. When the obtained resist pattern was observed with a scanning electron microscope, it was found that a 0.6 μm line-and-space positive type pattern could be resolved. The results are shown in Table-1.

Examples 7-8 To 100 parts by weight of commercially available polyhydroxystyrene (Nyresin-M, manufactured by Maruzen Petrochemical Co., Ltd.), the radiation-sensitive compound and alkali dissolution-inhibiting compound shown in Table 1 were added to propylene glycol monoethyl ether acetate in a predetermined ratio. A solution of the composition of the present invention was prepared by dissolving and having a solid content concentration of 20% by weight. Next, the resist film reduction rate was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained.

In addition, in the same manner as in Example 1, far ultraviolet rays were irradiated through a pattern mask using a far ultraviolet contact exposure machine at the far ultraviolet irradiation amount shown in Table 1.
It was developed with an MA aqueous solution for 1 minute, rinsed with water, and dried. When the obtained resist pattern was observed with a scanning electron microscope, it was found that a 0.6 μm line-and-space positive type pattern could be resolved. The results are shown in Table-1.

The following margin f0 Effect of the invention The positive radiation-sensitive resin composition of the invention is composed of an alkali-soluble resin, a radiation-sensitive compound, and a compound having an alkali dissolution suppressing function, and is resistant to short-wavelength radiation such as deep ultraviolet rays and excimer laser. Even when used as a source, there is no film loss in areas not irradiated with radiation during development with an alkaline aqueous solution, and a resist pattern with a good profile can be achieved at high resolution.

The positive radiation-sensitive resin composition of the present invention further includes ultraviolet rays,
It is also sensitive to radiation such as electron beams, X-rays, and synchrotron radiation, and is suitable as a resist for producing high-density integrated circuits.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] an alkali-soluble resin capable of forming a film with a dissolution rate of 10,000 A/min or less in a 1% by weight aqueous solution of tetramethylammonium hydroxide at 25°C; and at least one radiation-sensitive compound selected from diazoketones and diazosulfones; 1. A positive radiation-sensitive resin composition comprising a compound having a function of suppressing dissolution of an alkali-soluble resin in an alkaline aqueous solution.