JPH01180888A - Organosilicon compound and resist containing silicon - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R1-R3 are 1-20C alkyl or aryl; at least one of R4-R8 is silyloxy and the remains are 1a-20C alkyl or aryl). EXAMPLE:A compound represented by formula II. USE:Useful as a resist material, a hardening agent or for production of a minute and high integrated semiconductor device. PREPARATION:Chlorosilane is partially substituted by alkyloxy groups and the unsubstituted Sn-Cl are reacted with trimethylsilylated chlorophenol in sodium to provide a compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a silicon-containing resist containing a novel organosilicon compound and a polymer obtained by hydrolyzing the compound.

(Prior art) Recently, a resist that can be dissolved in an alkaline solution, developed, and has excellent oxygen RIE resistance has been developed, which contains a polymer in which silicon is introduced into the main chain and a phenol group is bonded to the silicon. Active efforts are being made to develop silicon-containing resists. However, although trimethylsilylphenol has been known as a silicon compound in which a phenol group is directly bonded to silicon, it has a functional group necessary for polymerization and is suitable as a starting material for the polymer of the silicon-containing resist having a phenol group. There are no reports of silicon compounds.

(Problems to be Solved by the Invention) The present invention was made to solve the above conventional problems, and provides an organosilicon compound having a silyl ether structure that can be used for polymerization and other reactions, and The object of the present invention is to provide a silicon-containing resist that includes a polymer obtained by hydrolyzing an organosilicon compound and is capable of alkaline development and has excellent oxygen RIE resistance.

[Structure of the Invention] (Measures for Solving the Problems) The first invention of the present application is -Momonena (I) (However, R1-R3 in the formula is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. , a substituted or unsubstituted aryl group, R, ~R8 is at least one silyloxy group,
The remainder is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group).

Specific examples of the organosilicon compounds represented by the general formula (I) according to the present invention are shown in Table 1 below.

In the organosilicon compound according to the present invention, for example, a part of chlorosilane is substituted with an alkyloxy group, and the remaining Si-
It is synthesized by reacting CI with trimethylsilylated chlorophenol in sodium.

Next, a silicon-containing resist, which is the second invention of the present application, will be explained.

The silicon-containing resist of the second invention of the present application has a composition containing a photosensitive agent and a polymer obtained by hydrolyzing the organosilicon compound represented by the general formula (I) in water with an alkali or acid.

Examples of the photosensitizer include naphthoquinone diazide compounds, azide compounds, diazo compounds, and the like. Specific examples of these photosensitizers are shown in Table 2 below.

The above photosensitizer may be used in an amount of 5 to 5 parts by weight based on 100 parts by weight of the above polymer.
It is desirable to mix 80 parts by weight. The reason for this is that if the amount of the photosensitizer is less than 5 parts by weight, it will not be possible to maintain sufficient solubility between the exposed and unexposed areas after the exposure, and on the other hand, if the amount of the photosensitizer is more than 80 parts by weight, This makes it difficult to prepare a resist solution, and the applicability to a substrate etc. may be impaired.

In addition to the above-mentioned polymer and photosensitizer, the silicon-containing resist according to the present invention may optionally contain an ultraviolet absorber, a surfactant, a sensitizer, a thermal polymerization inhibitor for storage stability, and a halation agent from the substrate. Antihalation agents to prevent halation, adhesion improvers to improve adhesion to substrates,
Surfactants to smooth the surface of the coating, or other polymers to modify the coating, such as epoxy resins, polymethyl methacrylate resins, propylene oxide-ethylene oxide copolymers, polystyrene, silicone rubber It is also possible to blend polymers and the like.

The silicon-containing resist according to the present invention is dissolved in a solvent and applied onto a predetermined substrate via a flattening layer. Examples of such solvents include ketone solvents such as cyclohexanone, acetone, methyl ethyl ketone, and methyl isobutyl ketone, cellosolve solvents such as methyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate, and ester solvents such as ethyl acetate, butyl acetate, and isoamyl acetate. Alternatively, a mixed solvent thereof may be used.

Next, a method for forming a pattern using a silicon-containing resist according to the second invention of the present application will be described in detail.

First, a polymer material layer (planarization layer) is formed on a substrate.

Examples of the substrate used here include a single silicon substrate doped with impurities, a semiconductor substrate in which a conductive film such as a polycrystalline silicon film is provided on the silicon substrate via a silicon oxide layer, and a blank mask. As the resin constituting the flattening layer, for example, any polymeric material that can be used to form a thin film can be used, and usually 0FPR-5000,0NP as a novolac UV resist.
R-800H8 (all product names manufactured by Tokyo Ohka Co., Ltd.), H
PR-204 (trade name manufactured by Hunt Co.) or a photosensitive silicone resin is used. Such a flattening layer can be formed by applying a solution in which the resin is dissolved in a solvent onto the substrate using a spinner, for example, and drying the solution. Suitable solvents used here include, for example, toluene, xylene, ethyl cellosolve acetate, and cyclohexanone. Furthermore, the solution may further contain additives such as diazide compounds for enhancing properties such as thermosetting properties. The viscosity of the solution is 20 to 100 cps, more preferably 60 to 10 cps, considering application using a spinner etc.
It is desirable to adjust to 0 cps. Furthermore, the thickness of the flattening layer is 1 to 2 μm, preferably 15 to 2.0 μm.
It is desirable to keep it in the range of . The reason for this is that if the thickness of the planarization layer deviates from the above range, there is a risk that the resolution will decrease or that a substrate with steps may not be planarized. Note that the solution may be applied onto the substrate, dried, and then subjected to baking treatment. The baking treatment conditions are either a temperature sufficient to evaporate the solvent and a temperature exceeding the glass transition point of the constituent resin of the flattening layer used, or usually
05-120 minutes at 50-250°C, preferably 80-120 minutes
The treatment is carried out at 220°C for 1 to 90 minutes, and in the case of photosensitive silicone resins, it is usually carried out at 50 to 200°C for 05 to 120 minutes, preferably at 80 to 120°C for 1 to 60 minutes.

Next, on the flattening layer, the silicon-containing alkali-soluble resin and a photosensitizer selected from a silicon-containing naphthoquinone siacite, a silicon-containing azide, or a compound represented by the above-mentioned compound (I), A resist layer is formed by applying the silicon-containing resist dissolved in the solvent using, for example, a spinner and drying it. The viscosity of the silicon-containing resist is 10 to 100 cps, more preferably 1O-6, considering application using a spinner or the like.
It is desirable to adjust it to 0 cps. Furthermore, the thickness of the resist layer is 0.1 to 1.0 μm, more preferably 0.1 μm.
It is desirable that the thickness be in the range of -0.6 μm. The reason for this is that if the thickness of the resist layer deviates from the above range, oxygen plasma resistance may be reduced or resolution may be reduced. Note that a silicon-containing resist may be applied on the planarization layer, dried, and then subjected to baking treatment. At this time, if the solvent remains in the resist layer, scattering of the exposure light increases, resulting in a decrease in resolution.

Next, the resist layer is exposed to radiation (for example, G line, ■ line,
Pattern exposure is performed by selectively irradiating with deep UV, excimer laser, etc. In this pattern exposure, either a contact exposure method or a projection exposure method can be adopted. Then, the exposed resist layer is developed with an alkaline aqueous solution to dissolve and remove exposed or unexposed portions to form an upper layer pattern. Examples of the aqueous alkaline solution used here include organic aqueous alkaline solutions such as an aqueous tetromethylammonium hydroxide solution, and inorganic aqueous solutions such as an aqueous ammonium solution, an aqueous sodium hydroxide solution, and an aqueous potassium hydroxide solution. Further, as a developing means, for example, a dipping method, a spray method, etc. can be adopted.

Next, using the upper layer pattern as a mask, the lower planarization layer is tri-etched using oxygen plasma (oxygen RI).
Do E). At this time, the upper layer pattern is exposed to oxygen, and a film having a composition close to silicon dioxide (Si02) is formed on the surface, and the planarization layer exposed from the pattern has an oxygen RIE resistance of 10 to 100 molds. It becomes like this. All the planarization layer exposed from the upper layer pattern is covered with oxygen R.
Optimal profiles are obtained by etching with IE. Note that etching by oxygen RIE is usually performed at I X 1O-4-I X 1O-1 torr
It is best to conduct the test for 1 to 120 minutes under conditions of 0.01 to 10 W/cI.

Next, the substrate is etched using the pattern formed by the above method as a mask. Wet etching, dry etching, etc. are used for etching, and 3μ
In the case of forming a fine pattern of less than m, dry etching is preferred.

In such etching, the remaining resist pattern is removed using a stripping agent such as J-100 (trade name, manufactured by Nagase Kasei Co., Ltd.) or oxygen gas plasma.

(Function) The organosilicon compound of the invention in Section 1 of the present application has a phenol group of a silyl ether structure directly connected to silicon in the main chain, and has a functional group necessary for polymerization in the side chain of the silicon. By hydrolysis, it is possible to easily synthesize a polymer in which a phenol group having a silyl ether structure is directly connected to silicon in the main chain, and thus useful resist materials and curing agents can be obtained.

Further, the silicon-containing resist of the invention of Section 2 of the present application has the general formula (
Since it is composed of a polymer obtained by hydrolyzing an organosilicon compound represented by 1) and a photosensitizer, it is highly sensitive to G-line, ■-line, deep UV light, excimer laser light, etc., and is highly sensitive to alkali. It can be developed, has excellent oxygen RIE resistance, and exhibits a good masking effect against dry etching of the underlying planarization layer caused by oxygen plasma. Therefore, it has excellent oxygen RIE resistance, is difficult to swell during the development process, and can achieve high resolution. Furthermore, by applying a two-layer lithography process, it is possible to form a fine two-layer pattern with the same aspect ratio. It becomes possible.

(Example of the invention) Synthesis examples and examples of the present invention will be described in detail below.

Synthesis Example 1 First, phenyltrichlorosilane 111L1 was dissolved in 3 parts of diethyl ether and cooled to -30°C. Subsequently, 2 mol of ethanol was added dropwise to this, and the mixture was allowed to react at room temperature for 3 hours. Thereafter, the mixture was cooled to o'C, and 2 mol of triethylamine was added dropwise, followed by filtration and distillation.

The m~trimethylunlyloxychlorosilane obtained by this distillation has a boiling point of 60°C/2 mmHg% yield of 3
It was 6%.

Next, 1 mol of sodium metal was added to 1 mol of toluene, heated at 110°C, and stirred to prepare a dispersion. Then, a mixture of 1 mol of phenyldiethoxychlorosilane and 1 ml of the ml-limethylsilyloxychlorosilane [1101] was added dropwise to the dispersion at 100°C to cause a reaction. After filtration, phenyl(m-trimethyloxyphenyl)jethoxysilane was synthesized by distillation.

Synthesized phenyl (■-trimethyloxyphenyl)
Shedoxin run has a boiling point of 135°C/2m[llH
g, yield was 23%. Further, when the I H-NMR spectrum of this compound was analyzed, the spectral characteristic diagram shown in FIG. 1 was obtained.

Synthesis Example 2 p instead of m-h lysotylsilyloxychlorosilane
Phenyl(p-trimethyloxyphenyl)jethoxysilane was synthesized in the same manner as Synthesis Example 1 except that -trimethyloxychlorosilane was used.

The synthesized phenyl(p-+-limethyloxyphenyl)shedkin silane has a boiling point of 130'C/1.5mm
Hg yield was 5%. Further, when the lH-NMR spectrum of this compound was analyzed, the spectral characteristic diagram shown in FIG. 2 was obtained.

Polymer production example 1 N
2 75 g of phenyl (m-trimethyloxyphenyl) jetoxysilane obtained in Synthesis Example 1 was added to 5 g of toluene in a gas stream.
A solution dissolved at 0M was added dropwise and an intermediate reaction was carried out at 120° C. to distill off toluene, nityl alcohol and hexamethyldisiloxane, followed by neutralization with hydrochloric acid and extraction with diethyl ether. Thereafter, after washing twice with pure water and concentrating, toluene was added dropwise to produce a solid content (polymer) [hereinafter referred to as Polymer A] Polymer Production Example 2 The phenyl (p -Trimethyloxyphenyl)jetoxysilane was hydrolyzed in the same manner as in Polymer Production Example 1, the ether layer was concentrated, and hexane was further added dropwise to obtain a solid content (polymer) [hereinafter referred to as Polymer B]. ] was manufactured.

Examples 1 to 7 First, polymers A and B produced according to Polymer Production Example 1.2 and photosensitizers (a) to (d) shown in Table 3 below
were blended in the proportions shown in Table 4 below, and the mixture was dissolved with ethyl cellosolve acetate to give a concentration of 2.
Seven 0% silicon-containing resists were prepared.

Next, a solution of Novolak-based Shimist (product name: 0NPR-800H8, manufactured by Tokyo Ohka Co., Ltd.) was applied onto the silicon substrate, dried, and then heat-treated at 200°C for 15 minutes to form a 20 μm thick flattening layer. Formed. Subsequently, each of the silicon-containing resists was applied and dried on the planarization layer of the silicon substrate to form a resist layer with a thickness of 06 μm. Exposure was carried out under the conditions of 035 and exposure amount shown in Table 4 of the same. Subsequently, each exposed resist layer was developed for 40 seconds with a 15% aqueous solution of tetramethylammonium hydroquine (TMAH) to form an upper layer pattern.

Next, each silicon substrate on which the upper layer pattern has been formed is subjected to a dry etching device (manufactured by Tokuda Seisakusho Co., Ltd., product name: 1ll).
RRIE), 2, x 10-” torr,
Reactive ion etching (RIE) using oxygen plasma was performed under the conditions of output 0 and OBW/cyJ to transfer the upper layer pattern to the lower planarization layer.

Therefore, regarding the present Examples 1 to 7, the oxygen RIE resistance of the upper layer pattern during RIE with oxygen plasma of the planarization layer using the upper layer pattern as a mask, and the oxygen RIE resistance of the upper layer pattern after RIE with oxygen plasma of the planarization layer using the upper layer pattern as a mask. The resolution of the two-layer pattern was investigated. The results are also listed in Table 4.

The oxygen RIE resistance of the upper layer pattern was evaluated from the ratio of the etching degree to the planarization layer.

As is clear from Table 4 below, it can be seen that the silicon-containing resist of the present invention has excellent oxygen RIE resistance and can form a fine upper layer pattern by alkaline development. Furthermore, it can be seen that by performing oxygen plasma RIE using the upper layer pattern as a mask, the pattern can be faithfully transferred to the planarization layer and a fine and highly accurate two-layer pattern can be formed.

[Effects of the Invention] As detailed above, according to the organosilicon compound of the present invention, a polymer in which a phenol group of a silyl ether structure is directly bonded to silicon in the main chain can be easily synthesized by hydrolysis, and as a result, a useful resist material, A hardening agent can be obtained.

Furthermore, the silicon-containing resist of the present invention has a high sensitivity to radiation of ~17-, is capable of alkaline development, and has excellent oxygen RIE resistance, and can be applied to a two-layer lithography process. Accordingly, a fine two-layer pattern having a high aspect ratio can be easily formed, and it has remarkable effects such as being able to be effectively used in manufacturing fine and highly integrated semiconductor devices.

Table 1 C2H5 Table 1 (continued) Table 2 Table 2 (continued) Table 3 1 24 -

[Brief explanation of the drawing]

Figure 1 shows phenyl (m-
IH of trimethyloxyphenyl)jethoxysilane
FIG. 2 is a diagram showing the I H-NMR spectrum of phenyl(p-trimethyloxyphenyl)jethoxysilane synthesized in Synthesis Example 2 of the present invention. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1), General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 to R_3 in the formula are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl group, R_4 to R_8 are at least one silyloxy group, the rest are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups)
An organosilicon compound represented by (2), General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 to R_3 in the formula are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl group, R_4 to R_8 are at least one silyloxy group, the rest are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups)
1. A silicon-containing resist comprising a polymer obtained by hydrolyzing an organosilicon compound represented by: and a photosensitizer.