JPS63106649A - Pattern forming method - Google Patents

Abstract

PURPOSE:To form a fine resist pattern with high accuracy by forming a flattening layer on a substrate, and a resist layer contg. specific organopolysiloxane on the flattening layer, and by etching the flattening layer after radiating radiations and developing the resist. CONSTITUTION:The titled method lies in forming the flattening layer on the substrate, and forming the resist layer contg. the organopolysiloxane having the structure shown by formula 1 on the flattening layer, followed by etching the flattening layer, after radiating radiation and developing the resist layer. In formula I, R<1> and R<2> are each an aromatic compd. residual group or a heterocyclic ring compd. residual group, R<3> is 1-10C hydrocarbon residual group or 1-10C halogen hydrocarbon residual group, R<4> is 1-6C hydrocarbon residual group or 1-6C halogenated hydrocarbon residual group, X is hydroxy group or a group capable of hydrolysing, (a) and (b) are each 0 or 1. Thus, the high resolution of a photosensitive material against radiations can be obtd., and the pattern having a high shape ratio can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming fine resist patterns with high precision.

[Conventional technology]

Conventionally, in the manufacture of semiconductor integrated circuits such as ICs and LSIs, a fine resist pattern is formed by applying photoresist onto a substrate, irradiating it with ultraviolet rays through a photomask, and developing it. Wet etching of the substrate portion is performed. However, in this series of patterning processes, there is a limit to the resolution due to the diffraction phenomenon of ultraviolet rays when irradiated with ultraviolet rays, and in wet etching, there is a side etching phenomenon, that is, etchant wraps around under the resist pattern area. Due to the phenomenon of etching and the influence of impurities in the etchant, fine resist patterns could not be etched well.

Therefore, instead of wet etching, a technique has been developed in which fine resist patterns are etched by dry etching using means such as gas plasma, reactive sputtering, and ion milling.

The resist used when dry etching is used as an etching method has high sensitivity to radiation,
It is necessary to be able to form fine resist patterns with high precision and to have high resistance to dry etching.

Furthermore, in order to realize multi-layer wiring and three-dimensional structure of elements for higher integration of semiconductor integrated circuits, it is necessary to form resist patterns on substrates with steps. requires a thicker resist film.

As a means of solving the above problem, there is a method of forming a resist pattern with a high shape ratio by using not only one layer of resist but also multiple layers of resist.

Here, the shape ratio represents the ratio of the height to the width of the formed resist pattern (height 7 width). As a method for forming a resist pattern with a high shape ratio, for example, a flattening layer made of an organic polymer such as polymethyl methacrylate or polyimide having a high melting temperature (and hardness and flattening ability) is formed as a first layer on the substrate. , and after forming a silicone resist layer as a second layer,
A method of manufacturing a resist pattern with a high shape ratio by forming a resist pattern by partially irradiating the second silicone resist layer with radiation and developing it, and then dry etching the first flattening layer. can be mentioned.

This method is achieved by increasing the dry etching rate ratio (selectivity) between the second layer and the first layer, but if carbon tetrachloride gas or the like is used as an etchant for dry etching, even the substrate will be etched. It also has the disadvantage of causing problems.

For this reason, in recent years, research has been conducted into using reactive ion etching (RIB) using oxygen plasma for etching the planarization layer.

According to this RIE method, the exposed portion of the organic flattening layer is oxidized to carbon dioxide, water, nitrogen dioxide, etc.
At the same time as it is scraped off, the second layer of silicone resist remaining on the planarization layer is also oxidized to form silicon dioxide (
It becomes vitrified (silica) and becomes a barrier against oxygen plasma, making it possible to obtain a fine resist pattern with a high shape ratio.

[Problem that the invention seeks to solve]

However, conventional silicone-based resists have various drawbacks, such as low sensitivity to radiation, and those with high molecular weights have relatively high sensitivity but low resolution.

The present invention was developed against the background of the above-mentioned conventional technical problems, and has high sensitivity to radiation and high resolution, and is also resistant to reactive ion etching using oxygen plasma. The purpose of the present invention is to provide a method for forming a fine resist pattern using a two-layer resist having high resistance.

[Means for solving problems]

That is, in the present invention, a planarization layer is formed on a substrate, and the following general formula (1) % formula % (1) (wherein R1 and R1 are the same or different, and aromatic compound residues are formed on the planarization layer) group, heterocyclic compound residue, hydrogen atom, halogen atom, cyano group or hydrocarbon residue having 1 to 4 carbon atoms, 1 to 4 carbon atoms
4 is a halogenated hydrocarbon residue, R'' is a hydrocarbon residue having 1 to 10 carbon atoms or a halogenated hydrocarbon residue having 1 to 10 carbon atoms, R4 is a hydrocarbon residue having 1 to 6 carbon atoms, or carbon (1 to 6 halogenated hydrocarbon residues, X is a hydroxyl group or a hydrolyzable group, a and b are 0 or l)
Provided is a pattern forming method characterized by forming a resist layer containing an organopolysiloxane having a structure represented by the following: irradiating with radiation, developing the resist layer, and then etching a flattening layer. It is.

In the present invention, it is first necessary to form a flattening layer on a substrate as a first layer, which is made of an organic polymer having a high melting temperature, high hardness, and flattening ability as described above.

Examples of materials for such a flattening layer include thermoplastic resins such as polymethyl methacrylate, novolak resin, and polymethylstyrene; thermosetting resins such as polyimide and epoxy resin; water-soluble polymers such as polyglutarimide and carboxymethyl cellulose; and quinonediazide-based positive resists.

At this time, the material forming the flattening layer is usually dissolved in an organic solvent to form a solution, and this is dried onto the substrate using a spinner or the like to form a dry film thickness of usually 0.5 to 5 μm, preferably 0.
．． It is coated to a thickness of 5 to 3 μm and heat treated at 70 to 200°C.

In addition, an anti-rusion agent may be added to the material forming the planarizing layer in order to enhance the antihalation ability of the planarizing layer. Examples of antihalation agents include oil-soluble dyes such as oil yellow, stilbene compounds, diazoaminobenzene compounds, coumarin compounds, and pyrazoline compounds.

Next, a resist layer containing organopolysiloxane (hereinafter simply referred to as "organopolysiloxane") having a structure represented by general formula (I) is formed on the first layer, which is the flattening layer.

This organopolysiloxane can be treated by radiation such as visible light, ultraviolet rays, far ultraviolet rays, electron beams, X-rays, and γ-rays.
It hardens rapidly at room temperature to form a cured film that is insoluble in solvents. For example, some organopolysiloxanes are disclosed in Japanese Patent Publication No. 52-5884, Japanese Patent Publication No. 53-36515,
This is disclosed in Japanese Patent Publication No. 53-38763.

In the present invention, R in the structure represented by general formula (1)
Among I and R2, aromatic compound residues or heterocyclic compound residues include aryl groups such as phenyl group, tolyl group, xylyl group, biphenyl group, and naphthyl group, and hydrogen of the aromatic ring of these aryl groups. Examples include those in which atoms are substituted with a nitro group, an alkoxy group, a furyl group, a pyridyl group, or the like.

Further, as the hydrocarbon residue having 1 to 4 carbon atoms for R1 and R2, for example, a methyl group, an ethyl group, an i-propyl group,
Examples include n-propyl group, t-butyl group, and d-butyl group.

Note that R1 and RZ may be substituted with a halogen atom such as a chlorine atom or a bromine atom.

R3 in the general formula is a hydrocarbon residue having 1 to 10 carbon atoms, such as alkylene groups such as methylene group, ethylene group, propylene group, tetramethylene group, decamethylene group, phenylene group, -Ch Ha CHz −
An arylene group such as CHz -1CHz Cb Ha CHz-, or a group in which these are substituted with a halogen atom such as a chlorine atom or a bromine atom, and R4 is a hydrocarbon residue having 1 to 6 carbon atoms, such as methyl Examples include ethyl L i-propyl group, n-propyl group, t-butyl group, n-butyl group, and groups in which these are substituted with halogen atoms such as chlorine atoms and bromine atoms.

Furthermore, X in general formula (1) is a hydroxyl group or a hydrolyzable group, such as an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group, or when these alkoxy groups are halogens such as a chlorine atom or a bromine atom. Examples include haloalkoxy groups substituted with atoms, halogen atoms such as chlorine atoms and bromine atoms, and acetoxy groups.

The organopolysiloxane used in the present invention can be synthesized, for example, as follows.

That is, (a) the following general formula (n) ・ ・ ・ ・ ・ ・ ・ (II) (wherein R'
s R", R3, R', a and X are the same as above.) and an organosilicon compound represented by the following general formula (
(DI) (wherein, R1 and X are the same as above, C is 0 or a positive number of 3 or less, d is a positive number of 4 or less, and O
<c+d≦4, and n=l~io, ooo. )
Obtained by reaction with silane or siloxane represented by

Specific examples of the organosilicon compound represented by the general formula (11) include γ-methacryloxypropyltrimethoxysilane, T-methacryloxypropylmethyldichlorosilane, T-acryloxypropylmethyldimethoxysilane, γ-methacrylic Oxypropylmethyldichlorosilane, T-cinnamoyloxypropylmethyldichlorosilane, γ-methacryloxypropyldimethoxysilane, β-acryloxyethyl-trimethoxysilane, β-acryloxyethyl-triethoxysilane, γ-acryloxypropyl root Rimethoxysilane, γ-acryloxypropyltriethoxysilane,
δ-acryloxybutyl-trimethoxysilane, δ-
Acryloxybutyl-triethoxysilane, ε-acryloxypentyl-trimethoxysilane, ε-acryloxypentyl-triethoxysilane, T-acryloxypropyl-dimethoxymonohydroxysilane, γ
-acryloxypropyl-monomethoxydihydroxysilane, β-methacryloxyethyl-trimethoxysilane, β-methacryloxyethyl-triethoxysilane, γ-methacryloxyethyltrimethoxysilane, γ-methacryloxyethyltriethoxysilane,
δ-methacryloxytrimethoxysilane, δ-methacryloxytriethoxysilane, ε-methacryloxypentyl-trimethoxysilane, S-methacryloxypentyl-triethoxysilane, T-methacryloxypropyldimethoxymonohydroxysilane, γ-methacryloxy propylmonomethoxydihydroxysilane,
β-cinnamoyloxyethyl-trimethoxysilane,
β-cinnamoyloxyethyl-triethoxysilane,
T-cinnamoyloxypropyl-trimethoxysilane, β-cinnamoylpropyl-triethoxysilane, δ
-cinnamoyloxybutyl-trimethoxysilane, δ
-cinnamoyloxybutyl~triethoxysilane, ε
-cinnamoyloxypentyl-trimethoxysilane,
ε-cinnamoyloxypentyl-triethoxysilane, γ-cinnamoyloxypropyldimethoxymonohydroxysilane, T-cinnamoyloxypropyl-monomethoxydihydroxysilane, β-halogenocinnamoyloxyethyl-trimethoxysilane, β-halogenocinnamo Moyloxyethyl-triethoxysilane, T-halogenocinnamoyloxypropyl-trimethoxysilane, T-halogenocinnamoyloxypropyl-triethoxysilane, δ-halogenocinnamoyloxybutyl-trimethoxysilane, δ-halogenocinnamoyloxy Butyl-triethoxysilane, ε-halogenocinnamoyloxypentyl-trimethoxysilane, ε-halogenocinnamoyloxypentyl-triethoxysilane,
Examples include γ-halogenocinnamoyloxypropyldimethoxymonohydroxylsilane.

These organosilicon compounds can be used alone or in combination of two or more.

Specific examples of the silane or siloxane represented by formula (III) include, for example, tetrachlorosilane, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, 2-ethylhexyltrichlorosilane, vinyltrichlorosilane, allyl Trichlorosilane, cyclohexyltrichlorosilane, phenyltrichlorosilane, benzyltrichlorosilane, styryltrichlorosilane, tolyltrichlorosilane, styryltrichlorosilane, tolyltrichlorosilane, chloromethyltrichlorosilane, 3.3.3-trifluoropropyltrichlorosilane, 3-bromopropyltrichlorosilane, dimethyldichlorosilane, methylethyldichlorosilane, methylbutyldichlorosilane, methylcyclohexyldichlorosilane, methylphenyldichlorosilane,
Methylvinyldichlorosilane, methylallyldichlorosilane, methyltolyldichlorosilane, 3,3.3-trifluoropropylmethyldichlorosilane, chloromethylphenyldichlorosilane, 3-chloropropylphenyldichlorosilane, diphenyldichlorosilane, phenylvinyldichlorosilane , phenylcyclohexyldichlorosilane, trimethylchlorosilane, methyldiphenylchlorosilane, diethylphenylchlorosilane, triphenylchlorosilane, dimethylphenylchlorosilane, dimethylchloromethylchlorosilane, 3,3.3-trifluoropropyldimethylchlorosilane, dicyclohexylchlorophenylchlorosilane, ethylisobutyl In halogenated silanes such as tolylchlorosilane and vinylethylphenylchlorosilane, or in these halogenated silane compounds, some or all of the chlorine atoms directly bonded to the silicon atoms are other halogen atoms, acetoxy groups, hydroxyl groups, or carbon atoms having 1 to 4 carbon atoms. Examples include silanes substituted with alkoxy groups, and siloxanes obtained by subjecting these to hydrolysis, dehydration, dehydrohalogenation, acetic acid removal, or dehalogenated alkyl reactions.

These silanes or siloxanes can be used alone or in combination of two or more.

Organopolysiloxane containing a structure represented by general formula (1) by reacting an organosilicon compound represented by general formula (ff) with a silane or siloxane represented by formula -a (I [I) In order to produce , when both the organosilicon compound represented by the general formula (II) and the silane or siloxane represented by the general formula (III) have a hydroxyl group bonded to a silicon atom, they are mixed. In other cases, the two may be mixed, hydrolyzed, and then subjected to dehydration condensation. At this time, in order to promote dehydration condensation, for example, sulfuric acid, phosphoric acid, titanate isopropyl ester, Known catalysts such as sodium ethoxide can be used.

The condensation reaction between the organosilicon compound represented by the general formula (n) and the silane or siloxane represented by the general formula (I[[) is generally carried out using an organic solvent such as benzene, toluene, xylene, dimethylformamide, diethyl formamide, dimethyl sulfoxide, diethyl sulfoxide,
Silane or siloxane is hydrolyzed at a temperature of 5 to 60°C in a solvent such as methyl ethyl ketone or methyl isobutyl ketone, and the hydrolyzate is heated. Potassium hydroxide, sodium hydroxide,
Basic catalysts such as pyridine can be used.

Furthermore, in order to make this condensation reaction proceed more quickly, it may be preferable to raise the temperature of the reaction system, and in this case, in order to protect the unsaturated group shown in general formula (1), It is preferable to add a thermal polymerization inhibitor such as quinones such as hydroquinone and benzoquinone, amine salts, and hydrazine salts to the reaction system.

The weight average molecular weight of the organopolysiloxane of the present invention in terms of polystyrene is usually 5.000 to 1.000,00.
It is 0.

However, in the present invention, polystyrene has an active hydrogen-containing group such as an alkyl group, a vinyl group, a phenyl group, a tolyl group, a xylyl group, and does not have a structure represented by the general formula (I). Converted weight average molecular weight is io, ooo ~ 1.0
00.000 may be used in combination with polyorganosiloxane.

Examples of such silicone polymers include methylvinylsiloxane, phenylvinylsiloxane, divinylsiloxane, dimethylsiloxane, methylphenylsiloxane, diethylsiloxane, ethylphenylsiloxane, ethylphenylsiloxane, diphenylsiloxane,
Examples include those having repeating structural units such as methyltolylsiloxane.

The terminal of the silicone polymer is preferably terminated with a group selected from a triorganosiloxy group, an alkoxy group, and a hydroxyl group. Examples of such triorganosiloxy group include a trimethylsiloxy group, a dimethylvinyl group, and a triorganosiloxy group. Examples of the alkoxy group include siloxy group, methylphenylvinylsiloxy group, methyldiphenylsiloxy group, and alkoxy group such as methoxy group, ethoxy group, i-propoxy group, and t-butoxy group.

When such a silicone polymer is used in combination, it is used in an amount of about 1.000 parts by weight or less, preferably about 500 parts by weight or less, per 100 parts by weight of the organopolysiloxane.

In the present invention, the resist containing organopolysiloxane is prepared by combining the organopolysiloxane and optionally a silicone polymer other than the organopolysiloxane with a solvent such as chlorobenzene, xylene, ethylbenzene,
Aromatic solvents such as toluene and anisole, ketone solvents such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone, chlorine solvents such as chloroform, carbon tetrachloride, and trichloroethane, or glycol solvents such as methyl cellosol rub acetate and diglyme. Obtained by dissolving.

At this time, the amount of solvent used is 1 organopolysiloxane
00 parts by weight, preferably 100 to 5,000 parts by weight, particularly preferably 100 to 3,000 parts by weight.

The resist containing organopolysiloxane used in the present invention may be used in combination with a radiation crosslinking agent, a radiation aggravating agent, and the like.

Examples of such radiation crosslinking agents include azide compounds, and azide compounds having an absorption wavelength range of 200 to 500 nm are preferably used. Specific examples of these azide compounds include 2,6-bis(
4'-azidobenzal)cyclohexanone, 2,6-bis(4'-azidobenzal)-4-methylcyclohexanone, 4.4'-diazidochalcone, 4.4'-diazidobiphenyl, 3.3'-diazidobiphenyl , 4.4
'-Diazido diphenylmethane, 3,3'-diazido diphenylmethane, 4.4'-diazido diphenylethane, 3.3'-diazido diphenylethane, 4.4'-diazido diphenyl ether, 3.3' -diazido diphenyl ether, 4.4'-diazido diphenyl sulfide, 3°3'-diazido diphenyl sulfide, 4.
4'-Diazido diphenyl sulfone, 3.3'-diazido diphenyl sulfone, 2.6-dichloro-4-nitroazidobenzet, azido diphenylamine, 4.4-
Diazidiphenylamine, 6-.

Examples include azide compounds such as azide-2-(4'-azidostyryl)benzimidazole, 4,4'-diamidostilbene, and azidonitrone, and two or more of these azide compounds can also be used in combination.

These radiation crosslinkers are organopolysiloxane 10
It is preferably used in an amount of 10 parts by weight or less, particularly preferably 8 parts by weight or less, relative to 0 parts by weight.

In addition, examples of radiosensitizers include Michael's ketone, 5-nitroacenaphthene, 2-nitrofluorene,
-Nitropyrene, 1,8-dinitropyrene, 1,2-benzoanthraquinone, pyrene-1,6-quinone, cyanoacridine, etc., and for example, 10 parts by weight or less are used per 100 parts by weight of the radiation crosslinking agent. It will be done.

Additionally, the organopolysiloxane-containing resists used in the present invention may contain stabilizers such as hydroquinone, methoxyphenol, pt-butylcatechol, 2,2'
- hydroxyaromatic compounds such as methylenebis(6-t-butyl-4-ethylphenol), benzoquinone,
Quinone compounds such as p-xyquinone, phenyl-β-
Amine compounds such as naphthylamine, p,p'-diphenylphenylenediamine, or dilaurylthiopropionate, 4,4'-thiobis(6-t-butyl-3-
methylphenol), 2,2'-thiobis(4-methyl-6-t-butylphenol), 2-(3,5-di-
It is also possible to add 3 parts by weight or less of a sulfur compound such as t-butyl-4-hydroxyanilino)-4,6-bis(N-octylthio)-s-)riazine to 100 parts by weight of the organopolysiloxane.

Furthermore, dyes, pigments, and other inorganic fillers can be added to the resist containing organopolysiloxane used in the present invention, if necessary.

The solid content concentration of the resist used in the present invention is usually 2
-50% by weight, preferably 3-50% by weight.

In the present invention, the organopolysiloxane-containing resist prepared as described above is applied onto the flattening layer, which is the first layer, using a spinner or the like to give a dry film thickness of usually 0.05.
~1. The resist layer is coated to a thickness of 0.1-0.8 μm, preferably 0.1-0.8 μm, and then is usually bre-baked at 70-110° C. to form a two-layer resist.

In the present invention, this two-layer resist is partially exposed to visible light,
After irradiating with radiation such as ultraviolet rays, deep ultraviolet rays, X-rays, electron beams, and gamma rays, the resist pattern is developed with a solvent to form a second layer of a resist pattern made of a cured product of organopolysiloxane.

Here, the developer used during development after radiation irradiation dissolves the dry film of the resist containing the organopolysiloxane used in the present invention in the non-irradiated area, and dissolves the cured product of the organopolysiloxane in the radiation irradiated area. For example, the above-mentioned solvents in the resist, or aprotic polar solvents such as dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, hexamethylformamide, and mixtures of ketones and alcohols, such as methyl ethyl ketone and isopropyl alcohol. Examples include liquid mixtures with

Further, after development, the resist pattern may be rinsed using a poor solvent containing isopropyl alcohol, ethyl alcohol, n-hebutane, n-pentane, or the like as a main component.

After development, heat treatment is performed at 90 to 200°C, and then RIE is performed using oxygen plasma. The resist layer remaining on the first layer is oxidized, vitrified, and changed to silicon dioxide.
While it acts as a barrier against oxygen plasma, in the unirradiated areas where no resist layer remains, the first layer, the planarization layer, is oxidized and disappears, making it difficult to create precise microscopic structures for manufacturing semiconductor integrated circuits. Pattern formation becomes possible.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited thereto.

Reference Example 1 124 parts by weight of a 30% by weight toluene solution of dihydroxydimethylpolysiloxane and 40 parts by weight of a 30% by weight toluene solution of a hydrolyzate of phenyltrichlorosilane were mixed, and 5 parts by weight of γ-methacryloxypropyltrimethoxysilane were mixed. .0 parts by weight, hydroquinone 0.01. Parts by weight and 0.46 parts by weight of p-)luenesulfonic acid were added, and the condensation reaction was carried out at a toluene reflux temperature, and the condensation reaction was continued for 48 hours while distilling off the water produced by the condensation, resulting in a polystyrene equivalent weight. Average molecular weight 20.000
of organopolysiloxane was obtained.

Reference Example 2 412 parts by weight of dihydroxyphenylmethylpolysiloxane, 412 parts by weight of toluene and 18.6 parts by weight of pyridine were charged into a four-way flask, and while stirring at room temperature, 24.2 parts by weight of γ-methacryloxypropylmethyldichlorosilane was added. After the completion of the dropwise addition, the mixture was heated to 60°C, stirred for 1 hour, and after cooling, the white precipitate formed was filtered off, and the toluene was distilled off under reduced pressure.
An organopolysiloxane was obtained. The weight average molecular weight of this organopolysiloxane in terms of polystyrene is 20
．． It was 000.

Example 1 A solution of polymethyl methacrylate dissolved in methyl ethyl ketone (solid content concentration 20% by weight) was applied as a flattening layer onto a silicon wafer using a spinner to a thickness of 1.5 μm after drying. It was heated and dried at ℃ for 30 minutes. The organopolysiloxane Log obtained in Reference Example 1 was dissolved in xylene to form a solution with a solid content concentration of 4% by weight on this flattening layer, and the film thickness after drying was 0.3 μm.
It was coated so that After pre-beta, electron beam irradiation was performed at an accelerating voltage of 20 KV.

After electron beam irradiation, the wafer was developed with a mixed solvent of methyl ethyl ketone:isopropyl alcohol (weight ratio) = 3:1 (7), and rinsed with isopropyl alcohol. As a result, a 0.6 μm line-and-space resist pattern of organopolysiloxane was formed.

Thereafter, RIE was performed in a parallel plate sputter etching apparatus using oxygen gas as an etchant gas under the conditions of an applied power of 200 W and an internal pressure of 0.4 Torr. Under these conditions, the etching rate of the resist pattern was 0, and the etching rate of the polymethyl methacrylate film was 3,000 people/min, and by etching for 5 minutes, the resist pattern was covered with the organo-onovopolysiloxane. The polymethyl methacrylate layer that was not present completely disappeared.

After etching, a 0.65 μm line and space pattern was formed with a film thickness of 1.6 μm.

Example 2 A solution of soluble polyimide (manufactured by Ciba Geigy, JXU21 B) dissolved in trichloroethane (solid content concentration 20% by weight) was dried as a flattening layer on a silicon wafer using a spinner to a film thickness of 1.5 μm. It was applied to a thick layer and dried by heating at 150° C. for 30 minutes. On this flattening layer, 10 g of the organopolysiloxane obtained in Reference Example 2 was dissolved in methyl isobutyl ketone to make a solution with a solid content concentration of 5% by weight, and a solution was applied so that the film thickness after drying was 0.25 μm. , and prebaked at 90° C. for 20 minutes in a nitrogen stream. After pre-beta, palladium Lα rays (4,3
7 people) through a mask, the wafer was exposed to methyl ethyl ketone:isopropyl alcohol (weight ratio) =
It was developed with a 3:1 mixed solvent and rinsed with isopropyl alcohol. As a result, a 0.5 μm line-and-space resist pattern was formed on the polyimide film. After that, using a parallel plate type sputter etching device, oxygen gas was used as an etchant gas, and the applied power was 200 W.
, RIE was performed under the conditions of an apparatus internal pressure of 0.4 Torr and oxygen gas. Under these conditions, the etching rate of the organopolysiloxane is O, and the etching rate of the polyimide film is 1.500 people/min. The polyimide layer completely disappeared. After etching, a 0.55 μm line and space pattern was formed with a film thickness of 1.6 μm.

〔Effect of the invention〕

The pattern forming method of the present invention is easier to handle than conventional pattern forming methods using silicone resists, can obtain high resolution with respect to radiation, and can form patterns with a significantly high shape ratio. This makes it possible to manufacture semiconductor circuits such as IC1LSI, VISI, and ULSI, highly integrated optical circuits such as optical IC1 optical waveguides, and photomasks and X-ray masks.

Claims (1)

[Claims] (1) Form a flattening layer on the substrate, and write the following general formula (I) on the flattening layer ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ・・・・・・・・・(I) (In the formula, R ^1 and R^2 are the same or different, and are an aromatic compound residue, a heterocyclic compound residue, a hydrogen atom, a halogen atom, a cyano group or a hydrocarbon residue having 1 to 4 carbon atoms, or a halogen having 1 to 4 carbon atoms. carbonized hydrocarbon residue, R^3 has 1 or more carbon atoms
10 hydrocarbon residues or halogenated hydrocarbon residues having 1 to 10 carbon atoms, R^4 is a hydrocarbon residue having 1 to 6 carbon atoms or a halogenated hydrocarbon residue having 1 to 6 carbon atoms, and X is A hydroxyl group or a hydrolyzable group, a and b represent 0 or 1. ) A pattern forming method comprising forming a resist layer containing an organopolysiloxane having a structure represented by the following formula, irradiating with radiation, developing the resist layer, and then etching a flattening layer.