JPS6360898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a resist pattern.
To explain in more detail, the present invention uses electron beams,
Negative resist pattern that involves dry development using oxygen plasma, argon gas plasma, oxygen-argon mixed gas plasma, oxygen-fluorine gas mixed gas plasma, etc. after exposure with radiation such as rays, ion beams, and deep UV rays. The present invention relates to a method of forming.

2. Description of the Related Art Conventionally, resists developed using a developer have been used to form resist patterns in the manufacture of electronic devices such as semiconductor integrated circuits. Examples include polymethyl methacrylate, which is a positive electron beam resist, and polyglycidyl methacrylate, which is a negative resist. Since these conventional resists are developed using a developer, the resists swell and contract during development, making it difficult to form submicron patterns.

Therefore, an object of the present invention is to enable the formation of a resist pattern by dry development and to facilitate the formation of a highly reliable fine resist pattern.

According to the present invention, a method for forming a resist pattern on a substrate is provided, and the method includes forming a resist pattern on the substrate using an unsaturated hydrocarbon containing vinyl, allyl, cinnamoyl or acrylic double bonds in its molecular structure. The following general formula for polymeric materials with bonds: [In the above formula, X represents a methyl group, phenyl group, biphenyl group, phenylamino group, phenoxy group, benzyl group, cyano group, vinyl group, or acetoxy group, and Y represents a hydrogen atom, a hydroxy group, an azide group, or a vinyl group. , ethoxy group, butoxy group, phenoxy group, halogen atom, benzyl group,
Represents a phenyl group, methyl group, t-butyl group, biphenyl group or acetoxy group, and Z is a phenyl group, hydroxy group, benzyl group, methyl group, t-
Butyl group, phenoxy group, halogen atom, biphenyl group, or acetoxy group] A resist composition containing 1 to 50% by weight of a silicon compound represented by the following formula is applied, and this resist layer is exposed to electron beams, X-rays, or ion beams. , DeeP is characterized by exposure to radiation such as UV radiation, followed by surface treatment or heat treatment with fluorine-containing plasma, and then development with plasma.

In the present invention, a resist material containing the same silicon compound in the polymer described in the present invention exhibits positive characteristics when dry-developed with plasma such as oxygen after exposure to radiation such as an electron beam, but relief baking is performed after exposure. Alternatively, this is based on the surprising finding that negative properties are exhibited when the surface is etched with fluorine-containing plasma and then dry developed with oxygen or other plasma.

Examples of polymeric materials having unsaturated hydrocarbon bonds in the molecular structure that can be used in the present invention include polymers of alkadienes such as 1,3-butadiene and isoprene, cyclized products thereof, or copolymerizable with these alkadienes. copolymers with such monomers, dicarboxylic acid diallyl ester polymers such as diallyl orthophthalate, diallyl isophthalate, and diallyl terephthalate, polymers such as triallyl cyanurate and triallyl isocyanurate, and their copolymers, polycinnamic acid Examples include polymeric materials having cinnamoyl groups such as vinyl, polymeric materials having acrylic or methacrylic groups in side chains or terminals, unsaturated polyesters, and the like.

On the other hand, as a silicon compound represented by the general formula that can be used in the present invention, bis(p-biphenyl)
Diphenylsilane, bis(phenylamino)dimethylsilane, t-butyldimethylchlorosilane,
t-Butyldiphenylchlorosilane, dibenzyldimethylsilane, dicyanodimethylsilane, diphenylsilanediol, tetraacetoxysilane, tetraphenoxysilane, tetraphenylsilane, tribenzylchlorosilane, triphenylchlorosilane, triphenylethylsilane, triphenylchlorosilane enylfluorosilane, triphenylsilane,
Examples include triphenylsilanol, triphenylsilyl azide, and triphenylvinylsilane.

The pattern forming method of the present invention can be carried out according to a conventional method by the following operations.
That is, as shown in FIG. 1A, first, a resist layer 2 is formed on a substrate 1. For example, apply a resist composition solution using a spin coating method and apply it at a temperature of 60 to 80℃.
Pre-bake for 10-30 minutes. Next, as shown in (B), this is exposed to an electron beam or the like. Next, this resist layer is treated with baking or fluorine-containing plasma as shown in FIG. A desired pattern 3 as shown in D is obtained.

To obtain the useful fluorine-containing plasma of the present invention,
For example, CF ₄ , C ₂ F ₆ , C ₃ F ₈ and mixtures of CF ₄ and O ₂ may be used.

According to the present invention, it is possible to accurately form a fine resist pattern by dry development using plasma processing.

The present invention will be further explained below with reference to Examples.

Example 1 0.43 g (22% by weight) of triphenylsilane was added to 1.5 g of cyclized polyisoprene and dissolved in 10.0 g of xylene to prepare a resist solution. This was applied to a silicon substrate using a spinner, and then heated at 60° C. for 30 minutes in a nitrogen stream. The film thickness of this resist was 1.20 μm. Next, it was exposed to an electron beam with an accelerating voltage of 30 KV at a dose of 1×10 ^-4 C/cm ² , and then placed in a parallel plate plasma etching device and etched at 6×
After reducing the pressure to 10 ^-5 Torr and evacuating the inside of the apparatus, perfluoropropane (C ₃ F ₈ ) was introduced. After plasma treatment for 5 minutes under the conditions of C ₃ F ₈ gas pressure 0.08 Torr, applied frequency 13.56 MHz, applied power 0.33 W/cm ² , exhaust to 6 × 10 ^-5 Torr, and further oxygen gas pressure 0.4 Torr and applied power When plasma treatment was performed for 8 minutes at 0.33 W/cm ² , the film thickness in the unexposed area became 0. At this time, the exposed area (1×10 ^-4 C/cm ² ) is 0.43μm
A negative pattern with a residual film thickness of . For comparison, when the same sample was exposed to electron beams at various irradiation doses and then treated with oxygen plasma under the same conditions for 30 minutes without C ₃ F ₈ plasma treatment, the resist in the exposed area was The portions that were etched away and exposed to a dose of 20×10 ⁻⁴ C/cm ² or more had a film thickness of 0, and the unexposed portions exhibited positive characteristics with a residual film thickness of 1.11 μm.

Example 2 The same sample as in Example 1 was exposed to light at a dose of 2×10 ^-4 C/cm ² in the same manner as in Example 1, and then exposed in a nitrogen stream.
Heated at 100°C for 30 minutes. Next, using a parallel plate plasma etching device, the oxygen gas pressure was
0.4Torr, applied power 0.33W/cm ² , applied frequency
After plasma treatment for 8 minutes and 30 seconds under the condition of 13.56MHz, the film thickness of the unexposed area becomes 0 and the exposed area (2×
A negative pattern with a residual film thickness of 0.45 μm (10 ⁻⁴ C/cm ² ) was obtained.

Example 3 The same sample as in Example 1 was exposed in the same manner as in Example 2.
After heat treatment, a parallel plate plasma etching device was used under the conditions of argon gas pressure of 0.3 Torr, applied power of 0.33 W/cm ² , and applied frequency of 13.56 MHz.
After plasma treatment for 25 minutes, the film thickness in the unexposed area became 0, and a negative pattern was obtained in which the exposed area (2×10 ⁻⁴ C/cm ² ) had a residual film thickness of 0.38 μm.

Example 4 20% by weight of triphenylsilane was added to polydiallyl orthophthalate and dissolved in cyclohexanone. This was applied to a silicon substrate using a spinner, and then heated at 60° C. for 30 minutes in a nitrogen stream. The film thickness of this resist was 1.18 μm. Next, exposure, heat treatment, and dry development were carried out in the same manner as in Example 2. However, the developing time was 7 minutes and 30 seconds. At this time, the film thickness of the unexposed area becomes 0, and the exposed area (2×10 ^-4 C/
A negative pattern with a residual film thickness of 0.43 μm (cm ² ) was obtained.

[Brief explanation of drawings]

FIG. 1 is a flow sheet schematically showing the process of forming a resist pattern by the method of the present invention. In the figure, 1 is a substrate, 2 is a resist layer, and 3 is an exposed portion.

Claims (1)

[Scope of Claims] 1. When forming a resist pattern on a substrate, a polymer material having an unsaturated hydrocarbon bond containing a vinyl, allyl, cinnamoyl or acrylic double bond in its molecular structure is used on the substrate. General formula below: [In the above formula, X represents a methyl group, phenyl group, biphenyl group, phenylamino group, phenoxy group, benzyl group, cyano group, vinyl group, or acetoxy group, and Y represents a hydrogen atom, a hydroxy group, an azide group, or a vinyl group. , ethoxy group, butoxy group, phenoxy group, halogen atom, benzyl group,
Represents a phenyl group, methyl group, t-butyl group, biphenyl group or acetoxy group, and Z is a phenyl group, hydroxy group, benzyl group, methyl group, t-
butyl group, phenoxy group, halogen atom, biphenyl group, or acetoxy group] A resist composition containing 1 to 50% by weight of a silicon compound represented by the following formula is applied, this resist layer is exposed to radiation, and then this resist composition is applied. A method characterized by surface treatment or heat treatment with a fluorine-containing plasma and subsequent development with a plasma.