JPS5988307A - Manufacture of product coated with silicon carbide - Google Patents

Abstract

PURPOSE:To manufacture easily a product coated with silicon carbide by thermally decomposing a specified organosilicon compound in a vapor phase, and depositing the resulting silicon carbide on a substrate. CONSTITUTION:An organosilicon compound having one or more Si-H bonds and no Si-X bond (X is halogen or O) is used. The organosilicon compound is preferably selected from methyl hydrogen silanes obtd. by thermally decomposing dimethylpolysilane represented by the formula (where (x) is an integer) at >=about 350 deg.C. A substrate such as a carbon plate, a metallic silicon plate, a ceramic plate or a metallic plate is placed in a reaction zone, and said organosilicon compound is introduced into the zone with a carrier gas such as H2, N2 or Ar. The compound is thermally decomposed at 700-1,400 deg.C in a vapor phase, and a reaction product (silicon carbide) is deposited on the substrate to coat the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a silicon carbide-free covering, particularly a silicon carbide-free covering in which the surfaces of various electronic materials are coated with silicon carbide.

It is well known that high-purity silicon carbide-free coatings have excellent heat resistance, oxidation resistance, chemical resistance, and even thermal conductivity, but this also has semiconductor characteristics. Therefore, attempts have been made to apply silicon carbide as a coating material for various electronic materials such as semiconductor substrates and jigs thereof.

On the other hand, conventional methods for applying crystalline silicon carbide coatings to the surfaces of various substrates include (1) heating silicon carbide to 2000°C;
A method for making a silicon carbide-free coating film by sublimating at a high temperature above and recrystallizing on a Ni substrate (see Japanese Patent Publication No. 41-9332), (2) (CBm) ns 5C14-nr
A method of thermally decomposing a mixed gas of n and a hydrocarbon adduct such as methane (41!) where n = 0 to 3]
(See British Patent No. 1039748), (3) Method of high-temperature pyrolysis of a mixed gas of a hydrogenated silicide (SiH) and a hydrocarbonated compound (see British Patent No. 1039748), C4 ) A method of heating SiO powder or a mixed powder of Si and carbon to a high temperature of 1,500°C or more (Japanese Patent Laid-Open No. 52
-42365) etc. are known. However, method (1) requires a high temperature of 2,000°C or higher, which limits the substrate size5, and method (2) requires extremely high temperatures. Another disadvantage is that it uses chlorosilanes, which are easily hydrolyzed and difficult to handle. In addition, method (3) can obtain crystalline silicon carbide heating at a relatively low temperature, but this method requires a large thermal decomposition temperature difference and speed difference between Sin and the hydrocarbon compound. However, there is the disadvantage that it is necessary to add HCl to the reaction system or to adjust the concentration of Sin and hydrocarbon compounds.Furthermore, method (4) requires a high temperature of 1500°C or more. The drawback of this method is that it limits the selection of substrates.

The present invention relates to a method for producing a silicon carbide-free coating that can overcome all of these disadvantages, and this silicon carbide has at least one hydrogen bond in its molecule, and is composed of silicon carbide.
An organosilicon compound 'i which does not contain X (X represents a halogen atom or an oxygen atom), which is characterized by being thermally decomposed in the gas phase at 700 to 1400°C and coating the substrate with silicon carbide. It is.

To explain this, the inventors of the present invention have conducted various studies on methods for applying high-purity silicon carbide coatings on various substrates, and have found that
Focusing on the fact that this organosilicon compound contains a 5' (H group) in its molecule, which thermally decomposes at a relatively low temperature, further research on andn was conducted, and SiX If the number does not include the weight, the number is 700~
Since it thermally decomposes to silicon carbide at 1400°C, and therefore silicon carbide can be easily obtained at a relatively low temperature compared to conventional methods, this base material can also be used relatively freely. The present invention has been completed by fully confirming that silicon carbide-free coverings and silicon carbide substrates using various metals, ceramic materials, etc. as base materials can be industrially advantageously manufactured. Ta.

As mentioned above, the organosilicon compound used as a starting material in the method of the present invention contains at least one 5i-H bond in its molecule, but does not contain a SiX bond, and this For example, the general formula Rt n-4-,
(Si) n is a monovalent hydrocarbon group selected from a hydrogen atom or a methyl group, an ethyl group, a globyl group, a phenyl group, a vinyl group, etc., at least one of which is a hydrogen atom; n is 1; [a positive number of ~4], and a general formula [where Rd is the same as above, R1 is a methylene group, ethylene group, or phenylene group, m is a positive number of 1 to 2]; Examples include a fullalkylene compound or a silphenylene compound, or an adduct having the main skeletons of both in the same molecule. And, as this organosiliconized adduct, the following formula % formula % CH3CM.

CD, CE.

CHs CHs CHs l 1 1 H-8i -CH, -8i -8i -Hl
1 1 CB, CH, CH.

Examples of silanes and poly-7ranes are shown in Table 1.
Methylhydrodiene silanes mainly composed of dimethylpoly7-rane obtained by thermal decomposition at a temperature of 350'C or higher are preferred. In addition, these ¥
Silicon carbide compounds can be produced by conventionally known methods, but they can be easily purified to a high degree by a distillation process, so silicon carbide obtained by vapor phase pyrolysis is It also has the advantage of being extremely pure.

In carrying out the method of the present invention, all of the above-mentioned organosilicon compounds may be introduced under normal pressure into a reaction zone heated to a predetermined temperature, and the organosilicon compounds may be thermally decomposed in this reaction zone. The organosiliconized adduct may be carried by using hydrogen gas, an inert gas such as nitrogen, helium, or argon, or a mixed gas thereof as a carrier gas. If the temperature of this reaction zone is below 700°C, the rate of thermal decomposition of this organosilicon compound is slow.
It is necessary to set the temperature above 1400℃ at A'.
If above, the growth rate of silicon carbide crystals will be improved, but the crystal growth will be non-uniform and the adhesion to the substrate will be poor.
It is sufficient that the temperature is in the range of 00 to 1200°C.

Note that it is not necessary to particularly limit the rt of the substrate used in carrying out the present invention, but in order to obtain a silicon carbide free covering for electronic materials (i), Ceramic materials such as metal silicon, sapphire, and silicon nitride, quartz glass, various metal plates, etc. may be used, and a silicon carbide coating of an appropriate thickness may be applied to the surface by the method described above.

The crystalline silicon carbide-free coating obtained by the method of the present invention has heat resistance, oxidation resistance, and chemical resistance, so it is widely used for various applications, especially semiconductors. substrate,
It is said to be useful as a jig for electronic materials, as well as various sealing materials and thermally conductive members. You may also try to obtain .

Examples of the method of the present invention will be given below, but they are not intended to limit the scope of the present invention.

Example 1 A graphitic carbon plate whose surface had been thoroughly cleaned was placed in a quartz tube and then heated to 980°C, and hydrogen gas containing 5 volumes of tetramethylsifuran was added to the tube. 100 C,
The carbon plate was introduced for 30 minutes at speeds C and A+, and after cooling, the carbon plate was taken out.
It was observed that a uniform microcrystalline coating of β-type SiC was applied.

Next, this carbon plate was repeatedly heated to 1,300°C in air, but there was no change in the surface coating, and this coating was strong and uniform to prevent oxidation, without pinballs. That was confirmed.

However, for comparison, the temperature of the reaction zone in the above was set to 14
When tetramethylsifuran was thermally decomposed under the same conditions as 50°C, it was found that the silicon carbide coating formed on the carbon plate was composed of β-type SiC with large and non-uniform crystals. Because of this, the surface was uneven, and it was also observed that there were cracks in some parts of the surface.

Example 2 A sapphire single crystal plate was placed in a quartz tube, and the nil 0
After heating to 50°C, a mixture of equal amounts of hydrogen gas and argon gas containing 5 volumes of dimethylsilane was added to 11 liters of gas.
oc, c. When the dimethylsilane was thermally decomposed by introducing the dimethylsilane at a rate of 7 minutes for 30 minutes, a silicon carbide coating with a thickness of approximately 5 μm was uniformly applied to the surface of the 7-year single crystal plate taken out after cooling. .

Example 3 A quartz glass tube' (i?1120℃ heated to >K3C
1i, CB.

150C,
When introduced for 30 minutes at a speed of 7 minutes, the inner surface of this quartz glass tube was coated with microcrystalline silicon carbide approximately 7 μm thick. It did not develop any cracks or peel off even when exposed to water, and was firmly adhered to the quartz glass surface.

Example A silicon plate was placed in a quartz tube, heated to 1030°C, and then hydrogen gas containing 5 volumes of tetramethyldisilane and argon gas containing 7 volumes of dimethylclane were added. , so n100C0C0/min, 50C0C0/
The silicon plate was coated with silicon carbide to a thickness of about 20 .mu.m when the silicon plate was introduced at a rate of 1.0 min over a period of 1 hour.

Next, this silicon plate was immersed in fluoronitric acid to dissolve and remove the silicon, yielding a carbonized substrate with a thickness of about 20 μm.

46

Claims (1)

[Claims] 1 Has at least one silicon-hydrogen bond in the molecule, SiX bond (X represents a halogen atom or an oxygen atom)
Organosiliconized adducts that do not contain
1. A method for producing a silicon carbide-free covering, which comprises performing vapor-phase pyrolysis in a gas phase to form a silicon carbide coating on a substrate.