JP2002037699A - Method of forming thin film of single crystal silicon carbide and apparatus of forming it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a thin film of single crystal silicon carbide at a low cost. SOLUTION: A silicon substrate 100 for forming the film is placed in a film formation room 200 and atmospheric temperature in the film forming room 200 is increased to 1200-1300 deg.C by heating while providing argon gas as inert gas G1, after finishing heating, the argon gas as the inert gas G1 is substituted by hydrogen gas G3 and propane gas as hydrocarbon gas G2 is flown with the ratio of 1-5% by volume of the hydrogen gas G3 for a predetermined time while flowing the hydrogen gas 3, so that the thin film of single crystal silicon carbide is formed on a surface of the silicon substrate 100 for forming the film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a single-crystal silicon carbide thin film and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art Single crystal silicon carbide (SiC) has attracted attention as a next-generation semiconductor device material because of its characteristics of excellent thermal and chemical stability, high mechanical strength, and high resistance to radiation. I have. However, at present, a technique for manufacturing a large-area single-crystal silicon carbide thin film has not been established.

As a conventional method for producing single-crystal silicon carbide, a sublimation recrystallization method using a seed crystal of silicon carbide and a plasma CVD method have been mainly used.

[0004]

However, the above-mentioned sublimation recrystallization method has a problem that a high-purity silicon carbide seed crystal is essential. Also, plasma CVD
The method has a problem that a high vacuum in a film forming chamber is required in a film forming process. That is, both methods are costly,
There was a problem in time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to easily and inexpensively form a single-crystal silicon carbide thin film to be used as a substrate for epitaxially growing gallium nitride, which is widely used as a substrate for forming a light emitting device. It is an object of the present invention to provide a method and an apparatus for manufacturing a single-crystal silicon carbide thin film that can be used.

[0006]

According to a method of manufacturing a single crystal silicon carbide thin film according to the present invention, a silicon substrate for film formation is set in a film formation chamber, and an atmosphere temperature in the film formation chamber is controlled while supplying an inert gas. Is heated to 1200 to 1300 ° C., and after the completion of the flammability, the inert gas is replaced with hydrogen gas.
The single-crystal silicon carbide thin film is formed on the surface of the film-forming silicon substrate by flowing at a rate of volume% for a predetermined time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of a manufacturing apparatus for performing a method for manufacturing a single crystal silicon carbide thin film according to an embodiment of the present invention.

First, a description will be given of a manufacturing apparatus for performing a method of manufacturing a single-crystal silicon carbide thin film according to an embodiment of the present invention. This manufacturing apparatus includes a silicon substrate 100 for film formation.
Is installed, and various gases G1 to G necessary for manufacturing a single crystal silicon carbide thin film in the film formation chamber 200 are provided.
Gas supply means 300 for supplying the gas supply 3 and the film forming chamber 200
Temperature control means 400 for controlling the ambient temperature inside the device, and gas processing means 500 for processing the gas supplied to the film forming chamber 200.

The film forming chamber 200 is made of silicon carbide, and a substrate holder 210 on which the film forming silicon substrate 100 can be set up is provided. This substrate holder 210 is also made of silicon carbide.

A heater as temperature control means 400 is provided around the film forming chamber 200. By energizing the heater, the ambient temperature inside the film forming chamber 200 is controlled.

A gas supply means 30 is provided in the film forming chamber 200.
0 is connected to a gas supply pipe 310. The gas supply pipe 310 includes three gas cylinders 320A, 320B,
20C. The gas supply pipe 310 is provided with a switching valve 330 to switch the gas supplied to the film forming chamber 200. The cylinder 320
A is filled with an argon gas as an inert gas G1, a cylinder 320B is filled with a propane gas as a hydrocarbon-based gas G2, and a cylinder 320C is filled with a hydrogen gas G3.

The film forming chamber 200 is provided with a gas exhaust pipe 510 constituting a part of the gas processing means 500. The gas exhaust pipe 510 is provided with the gas processing means 50.
0 is provided.
That is, safe processing is performed by burning the gas exhausted from the gas exhaust pipe 510. The substrate holder 210 is provided between the gas supply pipe 310 and the gas exhaust pipe 510 so that the silicon substrate 100 for film formation can be reliably exposed to the gas supplied to the film formation chamber 200. ing.

The method for manufacturing a single-crystal silicon carbide thin film using the manufacturing apparatus having the above-described structure includes the steps of: setting the film forming silicon substrate 100 in the film forming chamber 200; The ambient temperature in the membrane chamber 200 is set to 1200
1300 ° C., and after completion of flammability, the inert gas G1
Is replaced with hydrogen gas G3, and while flowing hydrogen gas G3,
The hydrocarbon gas G2 is added to the hydrogen gas G3 by 1 to 5
The single-crystal silicon carbide thin film is formed on the surface of the silicon substrate 100 for film formation by flowing at a rate of volume% for a predetermined time.

The silicon substrate 100 for film formation is, for example, an SOI substrate having a plane orientation (111).

For example, the temperature in the film formation chamber 200 is heated to 1200 to 1300 ° C. while supplying an argon gas as the inert gas G1 from the gas supply means 300 to the film formation chamber 200. By this heating, the silicon substrate for film formation 100
To remove moisture from.

When the heating is completed, the film forming chamber 200
Is replaced with a hydrogen gas G3. In this case, the switching valve 330 of the gas supply means 300 is switched. And this hydrogen gas G3
While flowing propane gas as a hydrocarbon-based gas G2 at a rate of 1 to 5% by volume with respect to the hydrogen gas G3 for 5 minutes. For example, the supply amount of the hydrogen gas G3 is 1000 cc.
/ Min, the propane gas as the hydrocarbon-based gas G2 is supplied at 10 cc / min. In this case, the temperature inside the film forming chamber 200 is set to 1270 ° C.

The hydrogen gas G3 and the propane gas as the hydrocarbon gas G2 are guided from the gas exhaust pipe 510 to the combustion device 520, and are not discharged to the outside by being burned.

In this manner, the silicon on the surface of the film-forming silicon substrate 100 reacts with the propane gas as the hydrocarbon-based gas G3, and the plane orientation of the silicon substrate 100 reaches a depth of about 100 nm from the surface of the film-forming silicon substrate 100. (111)
Is formed.

In the above-described embodiment, pits may be generated on the surface of the film formation silicon substrate 100 due to etching with argon gas during heating by the heater constituting the temperature control means 400. These pits have an adverse effect on the single crystal silicon carbide thin film to be manufactured. For this reason, at the time of cleaning the silicon substrate 100 for film formation, the silicon substrate 100 for film formation is added to a mixed solution of sulfuric acid and hydrogen peroxide solution (4: 1 in volume ratio).
There is a method of forming a protective oxide film on the surface of the film-forming silicon substrate 100 by immersing for a minute. By forming such a protective oxide film, it is possible to prevent the generation of the pits. When the protective oxide film is exposed to a hydrogen gas G3 which replaces an argon gas as an inert gas G1 at a high temperature exceeding 1200 ° C., the protective oxide film is reduced and completely removed by the hydrogen gas G3. The production of the thin film is not adversely affected.

In the above-described embodiment, an argon gas is used as an example of the inert gas G1, but another inert gas may be used. However, in terms of price, there is an advantage that argon gas can be obtained at the lowest cost. In particular, if a protective oxide film is formed to prevent the occurrence of pits,
Since it is not necessary to use expensive high-purity argon gas for heating, it is advantageous in terms of mass production cost.

Although propane gas has been described as an example of the hydrocarbon-based gas G2, another hydrocarbon-based gas such as ethylene gas, methane gas, or butane gas may be used. However, similar to argon gas, there is an advantage that propane gas can be obtained at the lowest cost in terms of price. In addition, propane gas is considered to be preferable from the viewpoint of the efficiency of producing a single-crystal silicon carbide thin film because the content of carbon atoms is larger than that of ethylene gas or methane gas.

[0022]

According to the method for producing a single-crystal silicon carbide thin film according to the present invention, a silicon substrate for film formation is installed in a film formation chamber,
While supplying the inert gas, the atmosphere temperature in the film forming chamber is set to 12
After heating to 00 to 1300 ° C., after the completion of the flammability, the inert gas is replaced with hydrogen gas, and the hydrocarbon gas is flown at a rate of 1 to 5% by volume to the hydrogen gas for a predetermined time while flowing the hydrogen gas. To form a single-crystal silicon carbide thin film on the surface of the silicon substrate for film formation.

This eliminates the need to evacuate the film forming chamber as in the prior art, which contributes to simplification of the process and consequent reduction of the manufacturing cost. In addition, a seed crystal of silicon carbide is not required at the time of film formation, and an existing silicon substrate or SOI substrate can be used, which contributes to increase in diameter and cost.

In another method of manufacturing a single-crystal silicon carbide thin film according to the present invention, a silicon substrate for film formation is immersed in a mixed solution of sulfuric acid and hydrogen peroxide to protect the surface of the silicon substrate for film formation. An oxide film is formed, the silicon substrate for film formation is set in a film formation chamber, and the atmosphere temperature in the film formation chamber is heated to 1200 to 1300 ° C. while supplying an inert gas. Is replaced with hydrogen gas, and a hydrocarbon-based gas is flown at a rate of 1 to 5% by volume with respect to the hydrogen gas for a predetermined time while flowing the hydrogen gas to form a single-crystal silicon carbide thin film on the surface of the silicon substrate for film formation. It is formed.

According to this method, a protective oxide film is formed on the surface of the film-forming silicon substrate, and the formation of pits formed on the surface of the film-forming silicon substrate when the inert gas is argon gas is prevented. There is an advantage that can be.

Further, the apparatus for manufacturing a single-crystal silicon carbide thin film according to the present invention comprises a film-forming chamber in which a silicon substrate for film formation is installed, and various kinds of equipment necessary for manufacturing the single-crystal silicon carbide thin film in the film-forming chamber. The apparatus includes gas supply means for supplying a gas, temperature control means for controlling an ambient temperature inside the film formation chamber, and gas processing means for processing the gas supplied to the film formation chamber. With such an apparatus, the above-described method for producing a single-crystal silicon carbide thin film can be easily implemented. In addition, since gas processing means is provided,
Safe treatment of exhaust gas is possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a manufacturing apparatus for performing a method for manufacturing a single-crystal silicon carbide thin film according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 100 silicon substrate for film formation 200 film formation chamber 300 gas supply means 400 temperature control means 500 gas treatment means G1 inert gas G2 hydrocarbon-based gas G3 hydrogen gas

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshiaki Obayashi 1-4-33 Kitakyuho-ji Temple, Yao-shi, Osaka Hoseiden Co., Ltd. (72) Keiji Mine 1-4-33 Kitakyuho-ji Temple, Yao-shi, Osaka Inside Hoshiden Co., Ltd. (72) Inventor Fumihiko Jobe 1-4-3 Kitakyuhoji, Yao-shi, Osaka F-term in Hoshiden Co., Ltd. 4G077 AA03 BE08 EA02 EC09 ED06 EE06 TC01 TC13 5F045 AB06 AB32 AC01 AD16 AD17 AF03 AF13 BB08 DP09 DQ04 EB11 EB15 EC05 EE12 EE14 EG07 EK21 EM09

Claims (3)

[Claims] 1. A silicon substrate for film formation is placed in a film formation chamber, and an atmosphere temperature in the film formation chamber is heated to 1200 to 1300 ° C. while supplying an inert gas. A single crystal silicon carbide thin film is formed on the surface of the silicon substrate for film formation by flowing a hydrocarbon-based gas at a ratio of 1 to 5% by volume with respect to the hydrogen gas for a predetermined time while flowing the hydrogen gas with the gas. A method for producing a single-crystal silicon carbide thin film, comprising: 2. A method for immersing a silicon substrate for film formation in a mixed solution of sulfuric acid and hydrogen peroxide to form a protective oxide film on the surface of the silicon substrate for film formation, and placing the silicon substrate for film formation in a film formation chamber And the atmosphere temperature in the film forming chamber is heated to 1200 to 1300 ° C. while supplying an inert gas, and after the completion of the flammability, the inert gas is replaced with a hydrogen gas. A method for producing a single-crystal silicon carbide thin film, comprising: forming a single-crystal silicon carbide thin film on a surface of a silicon substrate for film formation by flowing a gas at a rate of 1 to 5% by volume with respect to hydrogen gas for a predetermined time. 3. A film formation chamber in which a silicon substrate for film formation is installed, gas supply means for supplying various gases necessary for producing a single crystal silicon carbide thin film to the film formation chamber, An apparatus for producing a single-crystal silicon carbide thin film, comprising: temperature control means for controlling an internal atmosphere temperature; and gas processing means for processing a gas supplied to the film formation chamber.