JPS6377887A - Purifying method for organosilicon compound - Google Patents

Abstract

PURPOSE:To readily and efficiently remove a very small amount of impurities and obtain an organosilicon compound of high purity, by bringing the organosilicon compound containing the impurities into contact with an organomagnesium compound. CONSTITUTION:An organomagnesium compound, preferably Grignard reagent is added to an organosilicon compound containing impurities such as halogenated organic compounds, e.g. methyl chloride, ethyl bromide, chlorobenzene, biphenyl chloride, etc., and the resultant reaction mixture is stirred at preferably -70-+50 deg.C. The organosilicon compound is then separated to afford the aimed organosilicon compound of high purity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for purifying organosilicon compounds such as silanes and siloxanes.

[Conventional technology]

In recent years, as the use of silanes and siloxanes as materials for the semiconductor industry has progressed, trace amounts of methyl chloride, methyl bromide, chlorobenzene, and bromobenzene are contained as impurities.

It has become clear that halogenated organic compounds such as chlorobiphenyl and bromobiphenyl attack semiconductor substrates such as silicon wafers, causing material problems.

[Problem that the invention seeks to solve]

Therefore, the present invention simply and efficiently separates impurities such as halogenated organic compounds from organosilicon compounds, and
The purpose of this invention is to provide a method for purification.

c. Means for Solving Problems] The present inventors have found that the above object can be achieved and an organosilicon compound can be purified by the following method.

That is, the present invention provides a method for purifying an organosilicon compound, which comprises contacting an organosilicon compound containing impurities with an organomagnesium compound and then separating the organosilicon compound.

Organosilicon compounds to be purified in the present invention include organosilanes and organosiloxanes. Examples of organosilanes include alkylchlorosilanes such as dimethyldichlorosilane, diethyldichlorosilane, methyltrichlorosilane, ethyltrichlorosilane, trimethylchlorosilane, and triethylchlorosilane; dimethyldimethoxysilane, dimethyljethoxysilane, methyltrimethoxysilane, and methyl Alkylalkoxysilanes such as triethoxysilane, diethyldimethoxysilane, diethyljethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane; chlorosilanes with phenyl groups such as diphenyldichlorosilane, phenyltrichlorosilane, and triphenylchlorosilane ; diphenyldimethoxysilane,
Phenylalkoxysilanes such as phenyltrimethoxysilane, triphenylmethoxysilane, diphenyljethoxysilane, phenyltriethoxysilane, and triphenylethoxysilane; examples of organosiloxane include hexamethyldisiloxane, hexaethyldisiloxane, octa Chain siloxanes with alkyl groups such as methyltrisiloxane and decamethyltetrasiloxane; cyclic siloxanes with alkyl groups such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane ;Hexaphenyldisiloxane.

Examples include linear siloxanes having phenyl groups such as octaphenyltrisiloxane and decaffenytetrasiloxane, and branched siloxanes having methyl and phenyl groups such as phenyltris(trimethylsiloxy)silane.

The organomagnesium compounds used in the present invention include:
For example, the general formula: [wherein R is methyl, ethyl, propyl, or butyl.

Alkyl groups such as amyl, cycloalkyl groups such as cyclohexyl and methylcyclohexyl, and phenyl.

It is a hydrocarbon group such as an aryl group such as tolyl or ethylphenyl, and X is a halogen atom such as chlorine, bromine, or iodine. ] Grignard reagents represented by these and organic magnesium compounds such as dimethylmagnesium, diethylmagnesium, and diphenylmagnesium are mentioned, and Grignard reagents are particularly preferred.

Specific examples of the Grignard reagent mentioned above include the following. That is, methylmagnesium chloride,
tert-butylmagnesium chloride, methylmagnesium bromide, ethylmagnesium bromide,
tert-butylmagnesium bromide, methylmagnesium iodide.

These include phenylmagnesium chloride, phenylmagnesium bromide, phenylmagnesium iodide, and cyclohexylmagnesium chloride.

Examples of impurities removed by the method of the present invention include, but are not limited to, halogenated organic compounds as described above. The halogenated organic compounds to be removed include methyl chloride, methyl bromide, and ethyl chloride.

Examples include ethyl bromide, ethyl iodide, chlorobenzene, bromobenzene, iodobenzene, chlorinated biphenyl, brominated biphenyl, iodized biphenyl, and the like.

To bring an organomagnesium compound such as a Grignard reagent into contact with an organosilicon compound containing impurities, the Grignard reagent or the like is added to the organosilicon compound as a solution in a suitable aqueous solvent, preferably at -70 to 100°C, particularly preferably at -100°C. Stirring etc. may be performed at 70 to 50°C. At this time, the amount of the organomagnesium compound such as the Grignard reagent used is preferably 1 to 1000 times the molar amount of the halogenated organic compound contained as an impurity, particularly preferably 1 to 100 times the molar amount. Moreover, as a solvent for dissolving the Grignard reagent, ethers such as ethyl ether, butyl ether, and tetrahydrofuran are preferable. In addition, benzene,
Solvents that are inert to Grignard reagents such as toluene, xylene, and hexane are also available. Although the contact treatment time may be relatively short, it is usually desirably about 1 hour to 10 hours. The target purified silane or purified siloxane can be obtained by filtering the treated mixture and distilling the filtrate, or by washing with water, separating the aqueous solution layer, and then distilling it.

[For production]

The true reason why impurities can be easily separated by the method of the present invention is not clear, but the reason is that impurities in organosilicon compounds such as silanes and siloxanes are adsorbed to organomagnesium compounds such as Grignard reagents, or It is presumed that this is because separation becomes easier as a result of adsorption to the reaction product of the organosilicon compound and the organomagnesium compound.

〔Example〕

Next, the present invention will be specifically explained using examples.

Example 1 Octamethyltrisiloxane 5000 found by analysis to contain 0.05 moles of phenyl bromide
A solution of methylmagnesium chloride (concentration: 1 mol) dissolved in tetrahydrofuran was added to the solution at a temperature of 60°C. After stirring and contacting for 6 hours, the precipitate was filtered using a glass filter. Distillation of the filtrate yielded 4500 g of octamethyltrisiloxane. When the phenyl bromide in this octamethyltrisiloxane was analyzed by gas chromatography, the concentration was found to be 9.01 ppm or less.

Three types of octamethyltrisiloxane (A), unpurified octamethyltrisiloxane (B) purified above, and octamethyltrisiloxane (C) obtained by further distilling the unpurified octamethyltrisiloxane once, were prepared on a silicon wafer. A board test was conducted using the following.

Silicon substrate test method: A sample of octamethyltrisiloxane was applied to a dry thickness of 0.1 μm on the surface of a silicon substrate measuring 301 m (length) x 30 m (width) x 5 n (thickness) and air-dried.

Subsequently, a 20% strength by weight aqueous HF solution was passed over the surface to decompose and remove the octamethyltrisiloxane. Next, the spectrum due to CI3 electrons was analyzed by X-ray photoelectron spectroscopy (XPS) to examine the surface state.

The results were as follows.

A (unrefined)... Carbon remained.

C (single distillation)...Carbon remained.

Example 2 A solution of phenylmagnesium chloride (concentration 1 mol) in tetrahydrofuran was added to 5000 g of phenyltris(trimethylsiloxy)silane, which was found to contain 0.1 mol of promobiphenyl by analysis. It was added at a temperature of 0°C. After stirring and contacting for 2 hours, the precipitate was filtered using a glass filter. Distillation of the filtrate yielded 4600 g of phenyltris(trimethylsiloxy)silane. When the bromobiphenyl in this phenyltris(trimethylsiloxy)silane was analyzed by gas chromatography, the temperature was found to be below 1 ppm of Q,O. Substrate tests using silicon wafers were conducted in the same manner as in Example 1 for three types of phenyltris(trimethylsiloxy)silane: unpurified, purified, and once distilled. Results similar to those in Example 1 were obtained.

Example 3 5000 g of phenyltriethoxysilane analyzed to contain 0.1 mole of fluorobiphenyl
A solution of methylmagnesium bromide (1 mol concentration) dissolved in tetrahydrofuran was added thereto at a temperature of 40°C. After stirring and contacting for 10 hours, the precipitate was filtered using a glass filter. When one distillate of the filtrate was collected,
4200 g of phenyltriethoxysilane were obtained. Analysis of fluorobiphenyl in this phenyltriethoxysilane by gas chromatography revealed that its concentration was 0.01 ppm or less. A substrate test using a silicon wafer was performed in the same manner as in Example 1, and the product was unpurified.

This study was conducted on three types of phenyltriethoxysilanes that were purified and distilled only once. Results similar to those in Example 1 were obtained.

Example 4 5000 g of diphenyldimethoxysilane, which was found by analysis to contain 0.1 mole of iodobiphenyl.
of methylmagnesium iodide (in dibutyl ether)? The solution was added at a temperature of 30° C. (1 mole per degree). After stirring and contacting for 7 hours, the precipitate was filtered using a glass filter. Distillation of the filtrate yielded 4300 g of diphenyldimethoxysilane. When the iodobiphenyl in this diphenyldimethoxysilane was analyzed by gas chromatography, its concentration was 0.01 ppm or less.

A substrate test using a silicon wafer was conducted in the same manner as in Example 1 for three types of diphenyldimethoxysilane: unpurified, purified, and single distillation only. Results similar to those in Example 1 were obtained.

Example 5 A solution of phenylmagnesium iodide (concentration: 1 mol) dissolved in tetrahydrofuran was added to 50 QOg of diphenyldichlorosilane, which was found to contain 0.1 mol of bromobiphenyl by analysis, at a temperature of 10°C. Ta. After stirring and contacting for 10 hours, the precipitate was filtered using a glass filter. Distillation of the filtrate yielded 4370 g of diphenyldichlorosilane. When the bromobiphenyl in this diphenyldichlorosilane was analyzed by gas chromatography, its concentration was below Q, Ql ppm.

A substrate test using a silicon wafer was conducted in the same manner as in Example 1 for three types of diphenyldichlorosilane: unpurified, purified, and single distillation only. Results similar to those in Example 1 were obtained.

Example 6 A phenylmagnesium chloride solution (concentration 1 mol) dissolved in tetrahydrofuran was added to 5000 g of diphenyldichlorosilane, which was found to contain 0.1 mol of chlorobenzene by analysis, at a temperature of -10°C. Ta. After stirring and contacting for 3 hours, the precipitate was filtered using a glass filter. When the filtrate was distilled,
4400 g of diphenyldichlorosilane were obtained.

When the chlorobenzene in this diphenyldichlorosilane was analyzed by gas chromatography, its temperature was found to be 0.
．． It was less than 0.01 pp clear.

A substrate test using a silicon wafer was conducted in the same manner as in Example 1 for three types of diphenyldichlorosilane: unpurified, purified, and single distillation only. Results similar to those in Example 1 were obtained.

Example 7 A solution of diethyl ethergnesium bromide (concentration 1 mol) was added to 5000 g of dimethyldichlorosilane, which was found to contain 0.1 mol of methyl chloride by analysis, at a temperature of -2
Added at 0°C. After stirring and contacting for 1 hour, the precipitate was filtered using a glass filter. Distillation of the filtrate yielded 4500 g of dimethyldichlorosilane. When the methyl chloride in this dimethyldichlorosilane was analyzed by gas chromatography, its concentration was 0.01 ppm or less.

A substrate test using a silicon wafer was conducted in the same manner as in Example 1 for three types of dimethyldichlorosilane: unpurified, purified, and single-distilled.

Results similar to those of the example were obtained.

〔Effect of the invention〕

According to the method of the present invention, trace amounts of halogenated organic compounds contained in organosilicon compounds such as silanes and siloxanes can be effectively removed, and highly pure organosilicon compounds can be easily obtained. . The highly purified organosilicon compound thus obtained is extremely useful as a semiconductor industrial material.

Claims (1)

[Claims] A method for purifying an organosilicon compound comprising contacting an organosilicon compound containing impurities with an organomagnesium compound and then separating the organosilicon compound.