JPS6052845A - Pattern forming material - Google Patents

Abstract

PURPOSE:To extend the exposure or development latitude by using a specified polymer and a compound which produces a cation or anion seed under light or ionized radiation as principal components. CONSTITUTION:This pattern forming material sensitive to light or ionized radiation contains a polymer having silyl groups and a compound which produces a cation or anion seed under light or ionized radiation as principal components. The silyl groups in the polymer are easily eliminated by light or ionized radiation as a sensitizing means and by the action of a sensitizer, so when a developer which does not dissolve the polymer having silyl groups and dissolves a polymer prepd. by eliminating silyl groups is used after irradiating light or ionized radiation on the pattern forming material, a positive pattern is formed. When a developer which dissolves the polymer having silyl groups and does not dissolve a polymer prepd. by eliminating silyl groups is used, a negative pattern is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to patterning materials sensitive to light or ionizing radiation that are suitable as resists.

Conventional photoresists include polyvinyl cinnamate resists, cyclized rubber resists, etc. as negative resists, and naphthoquinone azide resists as positive resists, but both of these are so-called negative resists or positive resists. It can only be used as a mold resist, and a negative resist cannot be used as a positive resist, nor can a positive resist be used as a negative resist.

Recently, semiconductor integrated circuit manufacturing technology has progressed, from the conventional general-purpose integrated circuit manufacturing technology that involves exposure to ultraviolet rays, development, and then wet etching, to irradiation with ionizing radiation, development, and then dry etching to obtain ultra-high-density integrated circuits. Integrated circuit manufacturing technology is expanding to the latest technology. However, the conventional photoresists are limited in the number of steps in which they can be used due to the narrow tolerance of processes such as exposure, development, and etching.

The present invention was made against the background of these technical problems, and by selecting a 1-1 developer sensitive to light or ionizing radiation, it can be used for positive resists, A resists, G resists, and has dry etching resistance. The purpose of the present invention is to provide a pattern-forming material having properties.

That is, the present invention mainly comprises a polymer having a silyl group (hereinafter referred to as "silyl group-containing polymer") and a compound (hereinafter referred to as "sensitizer") that generates cation species or anion species by light or ionizing radiation. A pattern-forming material sensitive to light or ionizing radiation is provided.

The present invention is characterized in that a polymer containing silyl groups, which is completely different from conventional photoresists, is used as a pattern forming material.

Since the polymer applied to the present invention is a silyl group-containing polymer, the silyl group is easily eliminated by the action of a sensitizer and a sensitizer by light or ionizing radiation (hereinafter referred to as "silyl group elimination polymer"). Therefore, the pattern forming material of the present invention does not dissolve the silyl group-containing polymer after irradiation with light or ionizing radiation, but can be made into a positive type by using a developer that dissolves the silyl group-eliminating polymer. By using a developer that dissolves the silyl group-containing polymer but does not dissolve the silyl group-eliminating polymer, it is possible to form a negative pattern forming material, and it is possible to form a negative pattern forming material.
The scope of process application is very wide.

In the present invention, light refers to light with a wavelength of about 700 to 43 Q nm, including near ultraviolet rays and visible light, and ionizing radiation refers to light with a wavelength of about 43 Q nm to 43 Q nm, which has an ionizing effect.
It is a radiation of about 1A and includes deep ultraviolet rays, X-rays, γ-rays, charged particle beams, etc.

The structure of the silyl group-containing polymer used in the present invention can be changed by mixing it with a sensitizer and irradiating it with light or ionizing radiation.

The silyl group here refers to -5IR1a2R5 (where 几,
, 'n, and R3 represent a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, or -CH-Q)
However, such a silyl-funded polymer has the general formula (
It is a polymer or copolymer containing at least one type of repeating unit of 1) to (v).

-CH2-C-...([) C=0 0-(CH2)nO8i几, i(,2穐(Here, R
is a hydrogen atom or a methyl group, 'f3J1R2 and R3
(represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, or -''R2Q, where n is an integer of 1 to 4) The silyl group-containing polymer applied to the present invention preferably has 10 repeating units. Other repeating units, such as styrene, α-methylstyrene, methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, vinylpyridine, if it has a mole percentage or more, particularly preferably 30 mole or more, most preferably 50 mole or more. , a styrene monomer such as N-vinylpyrrolidone, an acrylate monomer, a nitrogen-containing vinyl monomer, etc. In a silyl group-containing polymer having less than 10 molar units of the repeating unit, the pattern forming material It does not have sufficient effect.

Next, a method for synthesizing a monomer forming a repeating unit having a silyl group and a method for polymerizing the monomer will be described in detail by giving specific examples.

p-vinylphenoxy t-butyldimethylsilane (
Synthesis and polymerization of VP-BDMS) (VP) CH2-CH H3CH6 (VP-BDMS) VP was synthesized with dimethylformamide (VP-BDMS) in the presence of imidazole.
The mixture is reacted with t-butyldimethylnolyl chloride in a DMF (DMF) solvent at room temperature for 4 hours, and the product is removed by distillation under reduced pressure.

The obtained VP-BDMS is polymerized with an anionic polymerization initiator such as n-butyllithium or lithium naphthalene or a radical polymerization initiator such as azobisinbutyronitrile or benzoyl peroxide to obtain a silyl group-containing polymer.

Such a silyl group-containing polymer does not lose its silyl group even when treated with methanol or water, is soluble in benzene and chloroform, and is insoluble in methanol, hexane, and acetone. When the obtained silyl group-containing polymer is used in the present invention and irradiated with light or ionizing radiation, it can easily become a silyl group-eliminating polymer, which is soluble in tetrahydrofuran, methanol, and acetone, and insoluble in benzene and chloroform. 0 p-(bistrimethylsilylamino)styrene (BT
Synthesis of MSAS) and its polymerization〉NF2 HNS i (
C)l:3) 3N(SICH5)2 (BTMSAS) To p-aminostyrene were added 5 times the mole of hexamethyldisilazane (HMDS) and 0.5 times the mole of trimethylsilyl chloride, and the mixture was refluxed for 2.5 hours under reduced pressure. When distilled, aminostyrene is almost quantitatively converted into trimethylsilane (TM8).
A substituted product is obtained.

Twice the mole of ethylmagnesium bromide (EtMgB'r) was added to this TMS substituted product, and tetrahydrone rane (
After reacting for 2 hours at a medium source (THF), 4 times the mole of trimethylsilyl chloride was added, left overnight, and distilled under reduced pressure to obtain BTMSA8. Obtained BTMS A 8
When this is polymerized using an anionic polymerization initiator such as lithium naphthalene or butyllithium or a radical polymerization initiator such as azobisisobutyronitrile or benzoyl peroxide, a silyl group-containing polymer that is stable at room temperature is obtained.

The obtained silyl group-containing polymer is tetrahydrofuran,
Soluble in benzene and chloroform, insoluble in reeds and methanol. Using this silyl group-containing polymer in the present invention,
When irradiated with light or ionizing radiation, n becomes a water-soluble silyl group-eliminated polymer under acidic conditions.

p-Vinylpheneroxytrimethylsilane (VPA-
8i) Synthesis and its polymerization> CH2CH20HCH2CH20HCH2CH20Sj
(V'PA-8i) p-vinylphenethyl alcohol (VPA) iC equivalent mole of hexamethyldisilazane (HMDS) was added and heated at 30°C.
After stirring under nitrogen for 10 hours, VPA-
Get 8i. Further, a Grignard reagent is added and purified MVPA-8i is obtained by vacuum distillation. The obtained VPA-8i is polymerized using an anionic polymerization initiator such as butyllithium or sodium naphthalene or a radical polymerization initiator such as azobisisobutyronitrile or benzoyl peroxide to obtain a 7lyl group-containing polymer.

When this silyl group-containing polymer is used in the present invention and is irradiated with light or ionizing radiation, it becomes soluble in methanol, dioxane, pyridine, tetrahydrofuran, benzene, and water.
A silyl group-eliminated polymer is obtained which is insoluble in chloroform.

As described above, cystyrene derivatives and (meth)acrylic acid ester derivatives can be polymerized by protecting the phenolic hydroxyl group, amino group, or alcoholic hydroxyl group in the monomer with a silyl group, and the obtained silyl group-containing These are just a few examples from which a silyl group can be easily removed from a polyester, but the silyl group-containing polymer in the present invention is not limited to these examples. As mentioned above, these monomers can also be copolymerized with other copolymerizable monomers and used as the polymer in the present invention.

The pattern forming material of the present invention uses a silyl group-containing polymer as described above, and preferably contains 1 to 60 parts by weight, particularly preferably 2 to 20 parts by weight, of a sensitizer per 100 parts by weight of the silyl group-containing polymer. . If the sensitizer is less than 1 part by weight, depending on the amount of energy of light or ionizing radiation, the irradiation effect will not be sufficient and the silyl group will not be removed sufficiently, while even if it exceeds 30 parts by weight, the effect of removing the silyl group will be sufficient. It is too much and no more is needed, which may lead to problems as a sensitizer-excessive material.

As the sensitizer that generates cationic species used in the present invention,
The following (1) to (7) can be exemplified, but any material may be used as long as it produces a siccation species upon irradiation with light or ionizing radiation.

(1) Onium salt As the onium salt, (R4()
) Sya, R5÷rj-Q-xc6 (X is SbF5.P
F5. ASF6. Examples of BF4, R4, lump and R6 include a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a nitro group, or a cyano group.

(2) Diazonium salt Examples of the diazonium salt include benzenediazonium, p-chlorobenzenediazonium, p-bromobenzenediazonium, 0-lm- or p-methylbenzenediazonium, 0- or p-
Methoxybenzenediazonium, p-dimethylaminobenzenediazonium, m-nitrobenzenediazonium, p-phenylbenzenediazonium td2,6-
Examples include arsenic hexafluoride, boron tetrafluoride, and phosphorus hexafluoride of dipromo-4-hydroxybenzenediazonium.

(3) p-quinonediazide compound: Examples of the p-quinonediazide compound include 2,6-dimethyl-p-quinonediazide and 2,6-di-t-butyl-p-quinonediazide.

(4) Solvent C with polyhalogenated hydrocarbon and active hydrogen
(hereinafter referred to as "active solvent"): Examples of polyhalogenated hydrocarbons include CBr4゜R, CBr, (R is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group)
Examples of R,yCBr- include tribromomethane and tribromotoluene. Examples of active solvents include toluene, ethylbenzene, and xylene.

(51YCZ (Y u 5O2CZ -Br, N
A combination of O, SCN, CN, or 5C1) and active hydrogen-0 et al.) A combination of R80CH2R2 (R8 and R2 are an alkyl group or phenyl group having 1 to 4 carbon atoms) and N in C, 0CR2B, Examples include ethyl isopropyl ether, butyl ether, ethyl phenyl ether, and ethyl dibenzyl ether.

combination) with benzene.

In addition, in the case of using an active solvent or benzene in combination in the above (4) to (2), the amount of the active solvent or benzene used is usually at least the equivalent molar amount relative to the target compound to be combined. It is also possible to use an active solvent or benzene as a solvent for dissolving the pattern-forming material in order to coat it on a substrate, and to use the active solvent or benzene remaining in the pattern-forming material after drying as the photosensitive agent.

Examples of sensitizers that release anionic species include, but are not limited to, triallylmethane leuconoid hydroxide: OH (X: -N(CH3)2, etc.). Any material that produces cyanion species upon irradiation with light or ionizing radiation may be used.

Thus, the pattern-forming material of the present invention is one whose main components are a polymer containing a silyl group and a sensitizer, and the pattern-forming material is prepared using an organic solvent to a solid content of 5 to 5.
30 weight resist solution and remove, silicone ueno-
It is applied with a spinner or the like onto a metal-coated substrate to form a film.

This coating is irradiated with light or ionizing radiation in a predetermined cross-section shape. In this way, the silyl group-containing polymer in the irradiated area becomes a silyl group-eliminating polymer, and if a developer that does not dissolve the silyl group-eliminating polymer but dissolves the silyl group-containing polymer is used, it is possible to make a negative-tone batter one by one. A positive pattern can be obtained by using a developer that dissolves the silyl group-eliminating polymer but does not dissolve the silyl group-containing polymer.

Further, by heat treatment at 100 to 200° C. and etching with a suitable etching solution or plasma, it is possible to precisely microfabricate substrates for manufacturing semiconductors, integrated circuits, etc.

As described above, according to the present invention, it is possible to provide a resist that can be either positive or negative type by selecting an appropriate solvent as a developer, and by combining an appropriate sensitizer. Since the energy range, that is, the wavelength of the light or ionizing radiation, can be selected, the conventional integrated circuit manufacturing process can be greatly expanded, and highly accurate etched images can be obtained with good reproducibility.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1 4-Vinylphenol (VP) t in 5 ml of dimethylformamide solvent in the presence of 12Pt'' imidazole 71
-Butyldimethylsilyl chloride was reacted at 30°C for 4 hours. Water was added to this reaction product, extracted with chloroform, dried over magnesium sulfate, and then distilled under reduced pressure.
-BDMS) was obtained. Yield: 76%, boiling point: 80℃1
It was 0.1 v+mHy.

Next, move to Mo/Mar (VP-BDMS) 23.4F)
n-butyl lithium 1, 6 in Rahronran 200d
ml (0,3+no7/A n-hexane solution) as a polymerization catalyst and polymerization was carried out at -78°C for 1 hour to obtain a polymer having a number average molecular weight of 48,000.

Dissolve the polymer in 1.1.2-trichloroethane to make a 10 weight solution, and add (o) as a sensitizer to this.
A resist solution was prepared by adding 10 parts by weight of 3SASF6 to 100 parts by weight of the polymer.

This resist solution was applied to a silicon wafer with a silicon oxide film using a spinner to a thickness of 0.8 μm, and dried at 80 to 90° C. for 15 minutes. This is 10
Ionizing radiation of 250 to 31 Qnm was irradiated through a resolution test chart chrome mask using a W low-pressure mercury lamp to print an image. When developed using isopropanol as a developer (dissolving and removing the irradiated area), the line width was 1 μm.
We were also able to resolve the pattern.

Example 2 80.5F of hexamethyldisilazane (I (MDS)) and 5.4y of trimethylsilyl chloride were added to 11.9ji' of p-aminostyrene, and the mixture was refluxed at 125°C for 2 hours and 60 minutes, followed by vacuum distillation (90°C, 15T1 mH: l ), almost quantitatively, aminostyrene substituted with trimethylsilane,
That is, p-(trimethylsilylamino)styrene was obtained. 26.6F of ethylmagnesium bromide was added to 19.1y of this I)-()limethylsilyl 7mi/)styrene, and the mixture was reacted for 2 hours at room temperature in dQml of tetrahydrofuran. Then, 46.2F of trimethylsilyl chloride was added to 19.1y of styrene.
After standing for 0 hours, p-C bistrimethylsilylamino)styrene (BTMSAS) was obtained by distillation under reduced pressure.

The yield was 84%.

Then, 26.3y of the monomer (BTMSAS) was dissolved in 1.4 m of n-butyllithium in 200d of tetrahydrofuran.
Polymerization was carried out at -78°C for 1 hour using 0.3m74tn-hexane solution as a polymerization catalyst, and the number average molecular weight was 65.0.
00 polymer was obtained.

This polymer was dissolved in 1.1.2-)lichloroethane to make a 10% by weight bath solution, and 10 parts by weight of 2,6-dimethyl-p-quinonediazide was added as a sensitizer to 100 parts by weight of poly-r. In addition, a resist solution was prepared. Using this resist solution, it was coated, dried, and irradiated with ionizing radiation to print an image in the same manner as in Example 1. When developed using benzene as a developer (unirradiated portions were dissolved and removed), a pattern with a line width of 1 μm could be resolved.

Example 6 p-vinylphenethyl alcohol (VPA) 14.9F
Hexamethyldisilazane (HMDS) 1611 was added to the solution under nitrogen at 60°C for 10 hours.
PA-8i) was obtained. Further, a Greeniere reagent was added and a monomer manufactured by M was obtained by vacuum distillation. The boiling point was 73°C, 72°C, and the yield was 87%.

Obtained model (VPA-8i) 22.1j
In 200 ml of tetrahydrofuran, 1.0 ml of n-butyllithium (0.3 ml/l n-hexane solution) was used as a laminated catalyst and polymerized at -78°C for 1 hour to obtain a polymer with a number average molecular weight of 72,000. .

A resist solution was prepared by adding 10 parts by weight of this polymer to 1.1.2-trichloroethane and 10 parts by weight of H (methylamino-triphenylmethane leucohydroxide) per 100 parts by weight of the polymer. Using this resist solution, it was applied, dried, and irradiated with ionizing radiation in the same manner as in Example 1 to print an image.

When developed using a mixed solvent of water and Impropatool mixed at a ratio of 1:1 (volume ratio) as a developer (the irradiated area was dissolved and removed), a pattern with a line width of 1 μm was also resolved at 1 μm.
- Obtained Patent Applicant: Shigetaka Shirai, Patent Attorney, Japan Synthetic Rubber Co., Ltd. 32

Claims (1)

[Claims] 1. A pattern-forming material sensitive to light or ionizing radiation, characterized in that the main components are a polymer having a silyl group and a compound that generates siccation species or anion species when exposed to light or ionizing radiation.