JPH07128859A - Resist composition - Google Patents

Abstract

PURPOSE:To obtain a satisfactory pattern shape even by etching in a subsequent process in a critical resolution region in the case of using as a resist compsn. for exposure with far UV, KrF excimer laser light, etc., by adding a specified sensitivity regulating agent. CONSTITUTION:This resist compsn. contains a resin which releases its protective groups by the action of an acid and becomes alkali-soluble, a photosensitive compd. which generates the acid by exposure, a compd. represented by formula I and a solvent. The resin may be replaced with a combination of an alkali- soluble resin with a compd. which releases its protective group by the action of the acid and becomes alkali-soluble or a combination of an alkalisoluble resin with a compd. which crosslinks the resin by the action of the acid and makes the resin slightly alkali-soluble. In the formula I, R<1> is H or a group represented by formula II (where R<4> is H, 1-4C straight chain or branched alkyl, etc.), R<2> is H or methyl and R<3> is H or-COOR<5> (R<5> is 1-4C straight chain or branched alkyl, etc.).

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION The present invention relates to a resist material used in the manufacture of semiconductor devices, etc., in particular, a positive type or negative type using an energy source such as far-ultraviolet light of 300 nm or less and KrF excimer laser light (248.4 nm). The present invention relates to a resist composition for forming a mold pattern.

[0002]

2. Description of the Related Art In recent years, with the high integration of semiconductor devices, the energy sources of exposure apparatuses used for microfabrication, especially photolithography, have become shorter and shorter in wavelength, and now far-ultraviolet light (300 nm or less) and KrF excimer are used. Laser light (24
8.4 nm), ArF excimer laser light (193 nm), etc. are under study. Higher sensitivity of the resist material is required for the use of these light sources, and for this purpose, a chemically amplified photoresist material using an acid generated by exposure as a medium has been proposed [H.Ito et al., Polym. Eng. .Sci., 23, 1012 (1983
Year)]. Since then, research on chemically amplified resist materials has progressed and many reports have been issued. Currently, 0.3 to 0.2 μm
A resist material having the above resolution performance has been reported. However, in the vicinity of the resolution limit of the chemically amplified resist material, a good pattern cannot be obtained due to the extremely small light contrast. For example, it has been pointed out that a resist material for a KrF excimer laser has a pattern shape of 0.3 μm or less that is not very good, scum is generated, and there is a problem during etching. A method of adding a basic material to a chemically amplified resist material has been proposed for the purpose of improving this drawback (Japanese Patent Laid-Open No. 5-127369). However, in this method, the resin in the resist composition and the basic compound are not sufficiently mixed with each other and are not dispersed or homogenized, so that the pattern shape becomes T-Shape or tapered and is not stable. Further, since the basic compound neutralizes the acid generated by exposure before the chemical amplification action, there is a problem in that it is impossible to adjust the delicate sensitivity which is practically important.

As described above, the chemically amplified resist material has a high sensitivity, can cope with the energy of the above-mentioned exposure apparatus, and has a remarkably improved resolution performance, but at the resolution limit, the pattern shape, In particular, there is a problem that the surface layer and the side wall of the resist film are defective and the resist cannot be etched to a desired size because the resist is peeled off during the etching process. Further, there is a problem that it is difficult to make a delicate sensitivity adjustment necessary for a practical resist. Therefore, there is a strong demand for a practical resist material which has a good pattern shape even near the resolution limit and can control delicate sensitivity.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation and provides a good pattern shape which does not cause a problem in an etching process at a resolution limit of 0.30 μm or less, and enables delicate sensitivity adjustment. It is intended to provide a practical resist composition.

[0005]

To achieve the above object, the present invention comprises the following configurations. “Any one of the following (i) to (iii),
(I) a resin that becomes alkaline-soluble by removing a protecting group by the action of an acid; (ii) a combination of a resin that is soluble in an alkali and a compound that becomes alkaline-soluble by removing a protecting group by the action of an acid; (iii) an alkali A combination of a soluble resin and a compound that crosslinks with the resin by the action of an acid to make the resin hardly soluble in an alkali, a photosensitive compound that generates an acid upon exposure, and the following general formula [1]

[0006]

[Chemical 3]

[Wherein R ¹ is a hydrogen atom or the following general formula [2]:

[0008]

[Chemical 4]

(In the formula, R ⁴ is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a halogen atom. the expressed.) represents, R ² represents a hydrogen atom or a methyl group, R ³
Is a hydrogen atom or -COOR ⁵ (In the formula, R ⁵ has 1 to 4 carbon atoms.
Represents a linear or branched alkyl group or a 2-hydroxyethyl group. ), K represents a natural number of 1 or more,
l represents a natural number of 0 or 1 or more. ] The resist composition characterized by including the compound shown by these, and a solvent. "

That is, the inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and as a result, they are extremely easily mixed with the conventional chemically amplified resist constituents and can adjust the exposure amount delicately. The inventors have found that by adding a resinous additive, a good pattern shape can be obtained even in the vicinity of the resolution limit of 0.30 μm or less which the latest chemically amplified resist material has, and completed the present invention.

As the dimensional width becomes finer, the contrast irradiated onto the resist film through the mask naturally lowers. Particularly when a mask having a dimension line width of 0.30 μm or less is used, some light leaks even on the resist film directly under the mask, and the light intensity is weak in the resist film directly under both ends of the mask. As described above, it is presumed that the chemical amplification reaction occurs due to the halfway light intensity especially around the area immediately below the mask, and as a result, the surface layer and the side wall of the resist film in the obtained pattern are deteriorated. Therefore, by adding a small amount of the compound represented by the above general formula [1] as a compound (sensitivity adjusting agent) capable of adjusting the exposure amount for the purpose of suppressing the chemical amplification reaction in the vicinity, it is possible to prevent a decrease in light contrast. As a result, it was confirmed that a positive or negative pattern having a good shape was obtained even at the resolution limit, and the object of the present invention could be achieved.

In the above general formula [1], R ¹ represents a hydrogen atom or a group represented by the general formula [2]. In the general formula [2], the number of carbon atoms represented by R ⁴ is 1 to 1. Examples of the alkyl group of 4 include a methyl group, an ethyl group, a propyl group and a butyl group, which may be linear or branched.
The alkoxy group having 1 to 4 carbon atoms represented by ^4, a methoxy group, an ethoxy group, a propoxy group, and butoxy group, linear, or at any branched.

Further, in the general formula [1], R ³ represents a hydrogen atom or --COOR ^5, and the number of carbon atoms represented by R ⁵ is 1.
Examples of the alkyl group of to 4 include a methyl group, an ethyl group, a propyl group, and a butyl group, which may be linear or branched.

Specific examples of the resin used in the present invention, which becomes alkali-soluble by removing a protective group by the action of an acid, include poly (p-tert-butoxystyrene / p-hydroxystyrene) and poly ( p-tert-butoxycarbonyloxystyrene / p-hydroxystyrene), poly (p-
Tetrahydropyranyloxystyrene / p-hydroxystyrene), poly (p-trimethylsilyloxystyrene /
p-hydroxystyrene), poly (p-1-methoxy-1-methylethoxystyrene / p-hydroxystyrene), poly (p-1-benzyloxy-1-methylethoxystyrene / p-
Hydroxystyrene), poly (p-1-ethoxyethoxystyrene / p-hydroxystyrene), poly (p-1-methoxyethoxystyrene / p-hydroxystyrene), poly (p-
1-n-butoxyethoxystyrene / p-hydroxystyrene), poly (p-1-isobutoxyethoxystyrene / p-hydroxystyrene), poly [p-1- (1,1-dimethylethoxy) -1-methylethoxy Styrene / p-hydroxystyrene], poly (p-tert-butoxystyrene / p-hydroxystyrene / methyl methacrylate), poly (p-1-ethoxyethoxystyrene / p-hydroxystyrene / fumaronitrile), poly (p-1 -Ethoxyethoxystyrene / p-hydroxystyrene / p-methylstyrene), poly (p-1-ethoxyethoxystyrene / p-hydroxystyrene / tert-butyl methacrylate), poly (p-1-ethoxyethoxystyrene / p- Hydroxystyrene / p-tert-butoxystyrene), poly (p-vinylphenoxyacetic acid 1-methylcyclohexyl), poly (p-vinylphenoxyacetic acid tert. −
Butyl / p-hydroxystyrene), poly (p-vinylphenoxyacetate tert-butyl / p-hydroxystyrene / methyl methacrylate), and the like, but are not limited thereto.

Specific examples of the alkali-soluble resin used in the present invention include, for example, poly (p-hydroxystyrene), poly (m-hydroxystyrene), poly (p-te).
rt-butoxystyrene / p-hydroxystyrene) [However, the ratio of the p-tert-butoxystyrene unit and the p-hydroxystyrene unit is limited to 2 ↓: 8 ↑. ], Poly (p-1-ethoxyethoxystyrene / p-hydroxystyrene) [However, the ratio of p-1-ethoxyethoxystyrene unit to p-hydroxystyrene unit is limited to 2 ↓: 8 ↑. ], Poly (p-vinylphenoxyacetate tert-butyl / p-hydroxystyrene) [However, the ratio of tert-butyl p-vinylphenoxyacetate units to p-hydroxystyrene units is limited to 2 ↓: 8 ↑. ], Etc.
Of course, it is not limited to these.

Specific examples of the compound used in the present invention, which becomes alkaline-soluble by reacting with the action of an acid (hereinafter abbreviated as a dissolution inhibitor compound), include, for example, 2,2-bis (4-tert. -Butoxyphenyl) propane, 2,2-bis (tetrahydropyranyloxyphenyl) propane, 2,
2-bis [4- (1-ethoxyethoxy) phenyl] propane, 2,2-bis [4- (1-methoxyethoxy) phenyl] propane, 2,2-bis [4- (1,1-dimethylethoxy) propane Examples thereof include phenyl] propane and 2,2-bis [4- (1-ethoxyethoxycarbonylmethoxy) phenyl] propane, but are not limited to these, and are generally used as dissolution inhibiting compounds in this field. Any known material may be used.

Specific examples of the compound used in the present invention that crosslinks with the resin by the action of an acid to make the resin sparingly soluble in alkali (hereinafter abbreviated as crosslinkable compound) are, for example, 1,2,4. -Tris (cyclohexyloxymethoxy) benzene, 1,2,4-tris (isobutoxymethoxy) benzene, 1,2,4-tris (isopropoxymethoxy) benzene, 1,3,5-tris (cyclohexyloxymethoxy) benzene 1,3,5-tris (isobutoxymethoxy) benzene, 1,3,5-tris (isopropoxy) benzene, 1,3-bis (cyclohexyloxymethoxy) benzene, 1,3-bis (isobutoxymethoxy) Benzene, 1,3-bis (isopropoxymethoxy) benzene, 1,4-bis (cyclohexyloxymethoxy) benzene, 1,4-bis (isobutoxymethoxy) benzene, 1,4-bis (isopoxy (Poxymethoxy) benzene, 2,4,6-tris (N, N-di-methoxymethylamino) -1,3,5-triazine, 2,4-bis (N, N-di-methoxymethylamino) -1 Examples include, but are not limited to, 3,3,5-triazine and the like.

Exposure used in the present invention [far-ultraviolet light (300 nm or less), KrF excimer laser light (248.4 nm)]
Etc.], a photosensitive compound that generates an acid (hereinafter, may be abbreviated as an acid generator) as long as it is a photosensitive compound that literally generates an acid by exposure and does not adversely affect the resist pattern formation. Any of these may be used, but particularly preferred in the present invention are, for example, 2-methanesulfonyl-2-methyl- (4-methylthio) propiophenone, 2-methyl-2- (p-toluenesulfonyl) proton. Piophenone, 2,4-dimethyl-2- (p-toluenesulfonyl) pentan-3-one, 2-cyclohexylcarbonyl-
2- (p-toluenesulfonyl) propane, diphenyldisulfone, di (p-tolyl) disulfone, diphenyldisulfone, dicyclohexyldisulfone, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl p-toluenesulfonyldiazomethane, bis (2,4- Dimethylbenzenesulfonyl) diazomethane, bis (p-chlorobenzenesulfonyl) diazomethane, bis (p-tert-butylbenzenesulfonyl) diazomethane, bis-benzenesulfonyldiazomethane, bis-cyclohexylsulfonyldiazomethane, bis (1,1-dimethylethylsulfonyl)
Diazomethane, p-toluenesulfonyl-cyclohexylsulfonyldiazomethane, p-toluenesulfonyl-cyclohexylcarbonyldiazomethane, p-toluenesulfonic acid benzoylphenylmethyl, p-toluenesulfonic acid silokuhexylcarbonyl, p-toluenesulfonic acid
1-cyclohexylmethyl and the like can be mentioned.

As the solvent used in the present invention, any of the above (i) to (iii), a photosensitive compound which generates an acid upon exposure, and a compound represented by the general formula [1] can be dissolved. Any material may be used, but a material having a good film-forming property is usually preferably used. Specifically, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl lactate, ethyl lactate, 2-ethoxyethyl acetate,
Methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, N-methyl-2-pyrrolidone, cyclohexanone, methyl ethyl ketone, 1,4-dioxane, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethylene glycol isopropyl Examples thereof include ethers, but the present invention is not limited thereto.

Specific examples of the compound represented by the general formula [1] according to the present invention (hereinafter sometimes referred to as "sensitivity adjusting agent according to the present invention") include, for example, poly (p-vinylpyridine), Poly (p-vinylpyridine / p-hydroxystyrene), Poly (p-vinylpyridine / styrene), Poly (p-
Vinylpyridine / p-chlorostyrene), poly (p-vinylstyrene / p-methylstyrene), poly (p-vinylpyridine / p-tert-butoxystyrene), poly (p-vinylpyridine / p-methoxystyrene), Poly (p-vinyl pyridine / methyl methacrylate), Poly (p-vinyl pyridine / tert-butyl methacrylate), Poly (p-vinyl pyridine /
2-hydroxyethyl methacrylate) and the like can be mentioned, but of course, the invention is not limited thereto.

The compound represented by the general formula [1] used as the sensitivity adjusting agent in the present invention can be easily obtained, for example, as follows. That is, for example, commercially available p-vinylpyridine alone or p-vinylpyridine and commercially available styrene, p-chlorostyrene, p-methylstyrene, p-tert-butoxystyrene, methyl methacrylate, tert-butyl methacrylate or methacrylic acid. Acid 2-hydroxyethyl etc., and a monomer in a catalytic amount [eg, azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 Examples include azo polymerization initiators such as'-azobis (methyl 2-methylpropionate) and 2,2'-azobis-sec-butyronitrile, and peroxide polymerization initiators such as benzoyl peroxide and lauroyl peroxide. . ] In the presence of an organic solvent such as toluene, benzene, tetrahydrofuran, 1,4-dioxane, etc., to carry out a polymerization reaction at 30 to 130 ° C. for 1 to 20 hours while passing a nitrogen or argon stream, and after the reaction, obtain the reaction solution as a polymer. Post-treatment according to a conventional method, or if necessary, the obtained polymer compound is further added with an organic solvent such as methanol, isopropanol, acetone, 1,4-dioxane, tetrahydrofuran, p-toluenesulfonic acid, oxalic acid. , 10-110 in the presence of acid such as sulfuric acid
After reacting for 30 minutes to 5 hours at ℃, if the reaction solution is post-treated according to a conventional method for obtaining a polymer, a weight average molecular weight (Mw)
A desired sensitivity adjusting agent of 00 to 50000 (GPC method using polystyrene as a standard) can be obtained.

The resist composition of the present invention usually contains the above-mentioned four components (any one of (i) to (iii), an acid generator, a sensitivity adjusting agent and a solvent) as main components, but if necessary, These include bleaching agents (for example, compounds having a diazoketo group, diazodiketo group or diazoketosulfonyl group in the molecule), dyes (for example, anthracene derivatives), plasticizers, surfactants (for example, nonionic or fluorine-based compounds). It is possible to add one or more of the above surfactants).

In the resist material of the present invention, the acid generator is usually 0.01 to 100 parts by weight with respect to 1 part by weight of the resin and the resin which becomes alkali-soluble by removing the protective group by the action of acid. 0.3 weight, Preferably 0.01-0.1 weight vicinity is mentioned.

In the resist material of the present invention, the mixing ratio of the alkali-soluble resin and the dissolution inhibiting compound is usually 0.1 to 0.5 weight, preferably 0.15 to 0.4 weight per 1 weight of the resin. The acid generator is usually 0.01 to 0.3 per 1 weight of the total of the alkali-soluble resin and the dissolution inhibitor compound and the acid generator as a mixing ratio of the alkali-soluble resin and the dissolution inhibitor compound.
The weight is preferably about 0.01 to 0.1 weight.

Further, in the resist material of the present invention, the mixing ratio of the alkali-soluble resin and the crosslinkable compound is usually 0.1 to 0.5 weight, preferably 0.15 to 0.4 weight, relative to 1 weight of the resin. The acid generator is usually added in an amount of about 0.01 to about 1% by weight of the alkali-soluble resin and the crosslinkable compound and the acid generator, which is the total of the alkali-soluble resin and the crosslinkable compound. 0.3 weight, Preferably 0.01-0.1 weight vicinity is mentioned.

The amount of the solvent in the resist material of the present invention is the composition of the above three types ((i) + acid generator, (ii)).
+ Acid generator, and (iii) + acid generator), the resist composition obtained as a result of dissolving each composition in which the sensitivity adjusting agent (compound represented by the general formula [1]) according to the present invention is added Is not particularly limited as long as it does not hinder the application on the substrate, usually a resin that becomes alkali-soluble by removing the protecting group by the action of an acid, or an alkali-soluble resin and a dissolution-inhibiting compound. Total, or total of alkali-soluble resin and crosslinkable compound, 1 to 1 weight each
20 weight, Preferably it is 1.5-6 weight vicinity.

The addition amount of the sensitivity adjusting agent according to the present invention is 0.001 to 2% with respect to the resin of various resist constituents,
More preferably, it is 0.01 to 1%.

The developing solution used in the various pattern forming methods as described above is suitable for increasing the difference in dissolution rate between the exposed and unexposed areas depending on the solubility of the resist composition. It suffices to select an alkaline solution having a concentration, and it is usually selected from the range of 0.01 to 20%. Examples of the alkaline solution used include solutions containing organic amines such as tetramethylammonium hydroxide (TMAH), choline and triethanolamine, and inorganic alkalis such as NaOH and KOH.

Pattern formation using the resist composition of the present invention may be carried out, for example, as follows.

A resist composition containing a slight amount of a sensitivity adjusting agent according to the present invention is applied to a semiconductor substrate such as a silicon wafer so that the thickness thereof is about 0.5 to 2 μm (0.1 when used as an upper layer of three layers). .About.0.5 .mu.m), and pre-bake this in an oven at 70 to 130.degree. C. for 10 to 30 minutes or on a hot plate at 70 to 130.degree. C. for 1 to 2 minutes. Then, a mask for forming a desired pattern is held over the resist film, and far ultraviolet light of 300 nm or less or KrF excimer laser light (248.4 nm) is exposed at an exposure amount of 1 to 100 mJ.
After irradiating so as to be about / cm ² , using a developing solution such as a 0.1 to 5% tetramethylammonium hydroxide (TMAH) aqueous solution for about 0.5 to 3 minutes, a dip method, a puddle method, By developing by a conventional method such as a spray method, the desired positive or negative pattern is formed on the substrate with a good shape.

[0031]

[Operation] When the sensitivity adjusting agent according to the present invention is added, a trace amount of acid generated by exposure is captured in a region where the light intensity is weak, for example, in the resist film surface layer and the resist film immediately below both ends of the mask. Therefore, the chemical amplification reaction does not proceed. On the other hand, since the chemical amplification reaction proceeds only in the region where the light intensity is high, it is possible to suppress the decrease in the contrast of the dissolution rate between the exposed part and the unexposed part due to the decrease in the light contrast caused by the ultrafine processing of 0.3 μm or less, As a result, the pattern shape at the resolution limit is improved.

The present invention will be described in more detail below with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited by these. The resin (polymer) and acid generator used in the examples are described in JP-A-4-21
1258, JP4-251259 (EP Publication 0520642), JP4-210960 (EP Publication 0440374), JP4-88348, JP4-173830, etc. It was synthesized according to the method described in.

[0033]

【Example】

Synthesis example 1. Synthesis of poly (p-vinylpyridine) 4.2 g (0.04 mol) of p-vinylpyridine with a catalytic amount of 2,2'-
Add azobis (2,4-dimethylvaleronitrile)
Polymerization reaction was carried out in 4-dioxane at 80 ° C. for 3 hours under a nitrogen stream. After cooling the reaction solution, it was poured into a 10% aqueous methanol solution for crystallization, and the precipitated crystals were collected by filtration, washed with a 10% aqueous methanol solution and dried under reduced pressure to give 3.8 g of poly (p-vinylpyridine).
Was obtained as a white powder crystal. The obtained polymer was subjected to GPC measurement (polystyrene standard) and was found to have a weight average molecular weight (Mw).
Was about 10,000 and the number average molecular weight (Mn) was about 5,500.

Synthesis Example 2. Poly (p-vinyl pyridine / p-te
Synthesis of rt-butoxystyrene) 2.1 g (0.02 mol) of p-vinylpyridine and 3.5 g (0.02 mol) of p-tert-butoxystyrene were added catalytic amount of 2,2'-azobis (methyl 2-methylpropionate). Then, a polymerization reaction was performed in toluene at 80 ° C. for 3 hours under a nitrogen stream. After cooling the reaction solution, it was poured into petroleum ether for crystallization, and the precipitated crystals were collected by filtration, washed with petroleum ether and dried under reduced pressure to give 5.3 g of poly (p-vinylpyridine / p-tert-butoxystyrene) as a white powder. Obtained as crystals. Mw: about 12000, Mn: about 6500.

Synthesis Example 3. Poly (p-vinylpyridine / p-
Synthesis of hydroxystyrene) Poly (p-vinylpyridine / p-tert-) obtained in Synthesis Example 2 above.
Butoxystyrene) 4.0 g dissolved in 1,4-dioxane,
3 ml of concentrated hydrochloric acid was added, and the mixture was stirred and refluxed for 2 hours. After cooling, the reaction solution was neutralized with triethylamine, poured into water for crystallization, and the precipitated crystals were collected by filtration, washed with water and dried under reduced pressure to give 3.0 g of poly (p-vinylpyridine / p-hydroxystyrene) as a white powder. Obtained as crystals. Mw: About 9600, Mn: About 5200.

Synthesis Example 4. Synthesis of poly (p-vinyl pyridine / methyl methacrylate) 2.1 g (0.02 mol) of p-vinyl pyridine and 2.0 g (0.02 mol) of methyl methacrylate with catalytic amount of 2,2'-azobis (2
-Methylbutyronitrile) was added, and a polymerization reaction was performed in toluene at 80 ° C for 4 hours under a nitrogen stream. After cooling, the reaction solution was poured into petroleum ether for crystallization, and the precipitated crystals were collected by filtration,
It was washed with petroleum ether and dried under reduced pressure to obtain 3.7 g of poly (p-vinylpyridine / methyl methacrylate) as white powder crystals. Mw: About 12000, Mn: About 7500.

Synthesis Example 5. Poly (p-vinylpyridine / p-
Synthesis of Methylstyrene) 2.1 g (0.02 mol) of p-vinylpyridine and 2.4 g (0.02 mol) of p-methylstyrene were subjected to the reaction and post-treatment in the same manner as in Synthesis Example 4 to give poly (p-vinylpyridine / 4.1 g of p-methylstyrene) was obtained as white powder crystals. Mw: About
12000, Mn: about 7200.

Synthesis Example 6. Synthesis of 1,3,5-tris (isopropoxymethoxy) benzene (1) Hydrogen chloride was added to a mixed solution of 75% paraformaldehyde 95.1 g (2.38 mol) and isopropanol 150.2 g (2.50 mol). After introducing and saturating and stirring at room temperature for 1 hour, the mixture was allowed to stand and then liquid-separated to collect an oily substance in the lower layer, which was dried over anhydrous calcium chloride. The desiccant is filtered off and the filtrate is distilled under reduced pressure b
190 g of isopropoxymethyl chloride was obtained as a colorless oily substance from p.36 to 39 ° C / 80 mmHg fraction. ¹ HNMR δ ppm (deuterated chloroform): 1.16 to 1.24 (6H, d, C
H ₃ × 2), 4.01 to 4.10 (1H, m, C H ), 5.55 (2H, s, C H ₂ ).

(2) 16.7 g (103.2 mmol) of phloroglucin was dissolved in 16.3 g (206.4 mmol) of pyridine, and 21.1 g (206.4 mmol) of acetic anhydride was added dropwise thereto at 20 to 30 ° C., and the mixture was stirred at room temperature for 5 hours. Let After standing overnight at room temperature, the reaction solution was poured into 400 ml of water, extracted 3 times with 100 ml of ethyl acetate, the organic layer was washed 5 times with 100 ml of water, and then dried over anhydrous magnesium sulfate. The desiccant was filtered off and concentrated under reduced pressure to obtain 10.6 g of the residual acetyl compound mixture as a yellow oil. The obtained acetyl form was confirmed to be a mixture of a mono form and a di form by ¹ H NMR measurement.

(3) Sodium hydride (60% under nitrogen stream)
(Containing) 5.65 g (0.14 mol) suspended in 55 ml of toluene,
Add to it the acetylated mixture obtained in (2) above at 35 ° C 10.6
25 ml of an N, N-dimethylformamide solution (g) was added dropwise, and the mixture was stirred at room temperature for 2 hours. Then, 15.0 g (0.14 mol) of isopropoxymethyl chloride obtained in the above (1) was added dropwise at 25 ° C or lower, and the mixture was reacted with stirring at room temperature for 3 hours. After standing overnight at room temperature,
The reaction solution was poured into 200 ml of ice water, and 250 ml of methylene chloride was added to 3 times.
Extracted twice. The organic layers were combined, washed with 200 ml of water twice, and dried over anhydrous magnesium sulfate. The desiccant was filtered off and concentrated under reduced pressure to give 10.1 g of a residual ether mixture as a brown oil. The obtained ether mixture was confirmed to be a mixture of 1-isopropoxymethoxy-3,5-diacetylbenzene and 1-acetyl-3,5-diisopropoxymethoxybenzene by ¹ H NMR measurement.

(4) 10.1 g of the ether mixture obtained in (3) above
And 30 g of anhydrous potassium carbonate were suspended in 120 ml of methanol, and the mixture was reacted with stirring at room temperature for 7 hours. After standing overnight at room temperature,
The reaction mixture was poured into 100 ml of water and extracted 3 times with 100 ml of ethyl acetate. The organic layers were combined, washed twice with 100 ml of water and then dried over anhydrous magnesium sulfate. The desiccant was filtered off and concentrated under reduced pressure to obtain 10.2 g of an oily residue. This oil was separated by column chromatography [filler: Wakogel C-200
(Wako Pure Chemical Industries, Ltd.); eluent: n-hexane / ethyl acetate = 1/1 (V / V)] to give 4.5 g of 3,5-bis (isopropoxymethoxy) phenol as a slightly yellow oil. Got as.

(5) Sodium hydride (60% under nitrogen stream)
0.40 g (10 millimoles) was suspended in 8 ml of N, N-dimethylformamide, and 1.20 g of 3,5-bis (isopropoxymethoxy) phenol obtained in (4) above at 25 ° C. or lower while cooling with ice water. 4 ml of a solution of (4.4 mmol) N, N-dimethylformamide was added dropwise, and the mixture was stirred at room temperature for 2 hours. Then, while cooling with ice water, 3.6 g (33 mmol) of isopropoxymethyl chloride obtained in the above (1) was added dropwise at 25 ° C or lower,
The reaction was allowed to stir at room temperature for 3 hours. After leaving it at room temperature overnight,
The reaction solution was poured into 50 ml of ice water and extracted 4 times with 10 ml of ethyl acetate. The organic layers were combined, washed 4 times with 20 ml of 5% NaOH aqueous solution, washed 3 times with 20 ml of water, and then dried over anhydrous magnesium sulfate. The desiccant was filtered off, and 3 g of a yellow oily substance obtained by concentration under reduced pressure was separated by column chromatography [filler: Wakogel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.); eluent: n-hexane / ethyl acetate = 10/1 → 5/1 → 3/1 (V / V)] and then 1,3,5-tris (isopropoxymethoxy) benzene 1.
16 g was obtained as a pale yellow oil. ¹ HNMR δ ppm (deuterated chloroform): 1.15 to 1.20 (18H,
d, C H ₃ x 6), 3.94 to 4.03 (3 H, m, C H x 3), 5.28 (6
H, s, C H ₂ × 3), 6.41 (3 H, s, aromatic ring hydrogen).

Example 1. A resist composition having the following composition was prepared, and patterns were formed as described below. Poly (p-tert-butoxystyrene / p-hydroxystyrene) 6.0 g 2-Cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane 0.3 g Poly (p-vinylpyridine) [Sensitivity modifier of Synthesis Example 1] 0.01 g Diethylene glycol dimethyl ether 13.7g

The above resist composition was spin-coated on a semiconductor substrate or the like and prebaked at 90 ° C. for 90 seconds on a hot plate to obtain a resist material film having a thickness of 1.0 μm. Then K
K using rF excimer laser stepper (NA 0.50)
rF excimer laser light (248.4 nm) was selectively exposed through the mask. Then, after baking on a hot plate at 110 ° C for 90 seconds, it is 60 times with an alkaline developer (2.38% TMAH aqueous solution).
By developing for 2 seconds, only the exposed portion of the resist film was dissolved and removed to obtain a positive pattern. The obtained positive pattern had a resolution performance of 0.24 μm line and space, and the pattern shape was good as shown in FIG. The exposure dose at this time was 35 mJ / cm ² .

Example 2. A resist composition having the following composition was prepared, and pattern formation was performed in the same manner as in Example 1. Poly (p-vinylphenol) 4.5g 2,2-bis (4-tert-butoxyphenyl) propane 1.5g Bis (1,1-dimethylethylsulfonyl) diazomethane 0.3g Poly (p-vinylpyridine / p-hydroxystyrene) [Sensitivity modifier of Synthesis Example 3] 0.02 g Propylene glycol monomethyl ether acetate 13.3 g

The positive pattern obtained had a resolution performance of 0.24 μm line and space, and the pattern shape was good as in Example 1. The exposure dose at this time was 33 mJ / cm ² .

Example 3. A resist composition having the following composition was prepared, and pattern formation was performed in the same manner as in Example 1. Poly (p-vinylphenol) 4.5 g 1,3,5-Tris (isopropoxymethoxy) benzene [Crosslinking agent of Synthesis Example 6] 1.8 g Bis (p-toluenesulfonyl) diazomethane 0.3 g Poly (p-vinylpyridine / p) -tert-Butoxystyrene) [Sensitivity modifier for Synthesis Example 2] 0.02 g Ethyl lactate 13.4 g

The obtained negative pattern had a resolution performance of 0.22 μm line and space, and the pattern shape was good as shown in FIG. The exposure dose at this time was 35 mJ / cm ² .

Example 4 A resist composition having the following composition was prepared and patterned in the same manner as in Example 1. Poly [p- (1-ethoxyethoxy) styrene / p-hydroxystyrene] 6.0 g Bis (cyclohexylsulfonyl) diazomethane 0.3 g Poly (p-vinylpyridine / methyl methacrylate) [Sensitivity modifier of Synthesis Example 4] 0.02 g Propylene Glycol monomethyl ether acetate 13.7g

The obtained positive type pattern had a resolution of 0.22 μm line and space, and the pattern shape was good as in Example 1. The exposure dose at this time was 33 mJ / cm ² .

Example 5. A resist composition having the following composition was prepared, and pattern formation was performed in the same manner as in Example 1. Poly (p-vinylphenoxyacetic acid 1-methylcyclohexyl / p-hydroxystyrene) 6.0 g 2,4-Dimethyl-2- (p-toluenesulfonyl) pentan-3-one 0.3 g Poly (p-vinylpyridine / p-methyl) Styrene) [Sensitivity modifier of Synthesis Example 5] 0.02 g Methyl 3-methoxypropionate 13.7 g

The obtained positive type pattern had a resolution performance of 0.24 μm line and space, and the pattern shape was good as in Example 1. The exposure dose at this time was 35 mJ / cm ² .

Comparative Example 1. A resist composition having the following composition was prepared, and pattern formation was performed in the same manner as in Example 1. Poly (p-tert-butoxystyrene / p-hydroxystyrene) 6.0 g 2-Cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane 0.3 g Diethylene glycol dimethyl ether 13.7 g

The obtained positive type pattern had a resolution performance of 0.24 μm line and space, but the pattern shape was poor as shown in FIG. The exposure dose at this time was 8 mJ / cm ² .

Comparative Example 2 A resist composition having the following composition was prepared and patterned in the same manner as in Example 1. Poly (p-vinylphenol) 4.5 g 2,2-bis (4-tert-butoxyphenyl) propane 1.5 g Bis (1,1-dimethylethylsulfonyl) diazomethane 0.3 g Propylene glycol monomethyl ether acetate 13.3 g

The obtained positive type pattern had a resolution performance of 0.24 μm line and space, but the pattern shape was poor as in Comparative Example 1. The exposure dose at this time was 10 mJ / cm ² .

Comparative Example 3 A resist composition having the following composition was prepared and patterned in the same manner as in Example 1. Poly (p-vinylphenol) 4.5g 1,3,5-Tris (isopropoxymethoxy) benzene 1.8g Bis (p-toluenesulfonyl) diazomethane 0.3g Ethyl lactate 13.4g

The negative pattern obtained had a resolution performance of 0.22 μm line and space, but the pattern shape was poor as shown in FIG. The exposure dose at this time was 12 mJ / cm ² .

Comparative Example 4 A resist composition having the following composition was prepared and patterned in the same manner as in Example 1. Poly [p- (1-ethoxyethoxy) styrene / p-hydroxystyrene] 6.0 g Bis (cyclohexylsulfonyl) diazomethane 0.3 g Propylene glycol monomethyl ether acetate 13.7 g

The obtained positive type pattern had a resolution performance of 0.22 μm line and space, but the pattern shape was poor as in Comparative Example 1. The exposure dose at this time was 10 mJ / cm ² .

Comparative Example 5 A resist composition having the following composition was prepared and patterned in the same manner as in Example 1. Poly (p-vinylphenoxyacetic acid 1-methylcyclohexyl / p-hydroxystyrene) 6.0 g 2,4-Dimethyl-2- (p-toluenesulfonyl) pentan-3-one 0.3 g Methyl 3-methoxypropionate 13.7 g

The obtained positive pattern had a resolution performance of 0.24 μm line and space, but the pattern shape was poor as in Comparative Example 1. The exposure dose at this time was 12 mJ / cm ² .

[0063]

As is clear from the above description, the chemically amplified resist composition containing a small amount of the sensitivity adjusting agent according to the present invention is exposed to far ultraviolet light of 300 nm or less, KrF excimer laser light (248.4 nm) or the like. When used as a resist composition for use in particular, it is possible to obtain a good pattern shape with no problem even in the etching in the subsequent step, particularly in the limit resolution region of 0.30 μm or less. Therefore, the present invention has great value for the formation of ultrafine patterns in the semiconductor industry and the like.

The resist composition of the present invention contains deep ultraviolet light,
Particularly effective in pattern formation using KrF excimer laser light, ArF excimer laser light, i-line light,
It can be sufficiently used in pattern formation using electron beams, X-rays and the like.

[0065]

[Brief description of drawings]

FIG. 1 is a 0.24 μm line-and-space positive type pattern obtained in Example 1 in which a small amount of a sensitivity adjusting agent according to the present invention was added.

FIG. 2 is a 0.22 μm line-and-space negative pattern obtained in Example 3 in which a trace amount of the sensitivity adjusting agent according to the present invention was added.

FIG. 3 is a 0.24 μm line-and-space positive pattern obtained in Comparative Example 1 in which the sensitivity adjusting agent according to the present invention is not added.

FIG. 4 is a 0.22 μm line-and-space negative pattern obtained in Comparative Example 3 in which the sensitivity adjusting agent according to the present invention is not added.

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[Procedure amendment]

[Submission date] December 6, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

By the action of the acid used in the present invention,
A compound that becomes alkali-soluble by removing the protecting group (hereinafter,
Abbreviated as dissolution inhibiting compound. Are specific examples of 2,2-bis (4-tert-butoxyphenyl) propane, 2,2-bis (tetrahydropyranyloxyphenyl) propane, 2,2-bis [4- (1-ethoxyethoxy). ) Phenyl] propane, 2,2-bis [4-
(1-Methoxyethoxy) phenyl] propane, 2,2
-Bis [4- (1,1-dimethylethoxy) phenyl]
Examples thereof include propane and 2,2-bis [4- (1-ethoxyethoxycarbonylmethoxy) phenyl] propane. However, the present invention is not limited to these and is generally known as a dissolution inhibiting compound in this field. It may be any as long as it is

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/312 7352-4M

Claims (2)

[Claims] 1. Any one of the following (i) to (iii):
(I) a resin that becomes alkaline-soluble by removing a protecting group by the action of an acid; (ii) a combination of a resin that is soluble in an alkali and a compound that becomes alkaline-soluble by removing a protecting group by the action of an acid; (iii) an alkali A combination of a soluble resin and a compound that crosslinks with the resin by the action of an acid to make the resin hardly soluble in an alkali, a photosensitive compound that generates an acid upon exposure, and the following general formula [1] [Wherein R ¹ is a hydrogen atom or the following general formula [2] (In the formula, R ⁴ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a halogen atom. ), R
² represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom or-
COOR ⁵ (In the formula, R ⁵ represents a linear or branched alkyl group having 1 to 4 carbon atoms, or a 2-hydroxyethyl group.)
, K represents a natural number of 1 or more, and l represents a natural number of 0 or 1 or more. ] The resist composition characterized by including the compound shown by these, and a solvent. 2. The resist composition according to claim 1, wherein the compound represented by the general formula [1] is contained in an amount of 0.01 to 1% based on the resin constituting the resist. [0001]