JP2002069649A - Device and method for film formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CVD device which forms film at a low cost by increasing use efficiency of source gas and especially forming film at high speed even on a large ring-shaped base substance. SOLUTION: A film forming device having a reacting vessel 1, a backing 2 for supporting the ring-shaped base substance 5 provided in the reacting vessel 1, and a means for heating the ring-shaped base substance 5, is characterized by a gas introducing means in a space inside the above ring-shaped base substance 5, for introducing reacting gas from the center of the ring-shaped base substance 5, to the internal circumferential surface and/or the top surface of the above ring-shaped base substance 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus which is excellent in high speed and uniformity and which can reduce the film forming cost by increasing the use efficiency of a raw material gas. The present invention relates to a film forming apparatus and a film forming method for forming a ceramic film such as a high-speed film by a CVD method.

[0002]

2. Description of the Related Art A CVD (Chemical Vapor Deposition) method is a kind of film forming method, and is called a chemical vapor deposition method, and is widely used as a process for producing semiconductors or liquid crystals or as a thin film forming method for surface treatment.

[0003] The thermal CVD method is a kind of the method, and has a simple reaction mechanism and is suitable for producing large-sized and complicated-shaped products. In particular, silicon carbide having a thickness of several mm synthesized by the thermal CVD method has been used as a high-purity material in a semiconductor manufacturing process in recent years, and further cost reduction is required.

However, in the conventional thermal CVD method, generally, the film forming rate is slow, so that a long time of film forming is required, the raw material use efficiency is low, and the cost of silicon carbide produced by the CVD method is high. I was In addition, when forming a film on a large substrate, the film thickness was likely to be non-uniform.

[0005] Therefore, in order to increase the uniformity of the film thickness and the film forming speed, the internal structure of the CVD furnace has been studied. At this time, since the reaction state of the gas is an important factor for the uniformity of the film thickness, the film formation rate, and the use efficiency of the source gas, it is necessary to improve the gas flow and the diffusion state of the molecules constituting the gas. A simple furnace structure or a furnace structure considering the temperature distribution of the substrate has been considered.

[0006] For example, the CVD apparatus disclosed in Japanese Patent Application Laid-Open No. 11-67675 has a reaction furnace 21 as shown in FIG.
The substrate 22 on which the film is to be formed is
Placed on the heater 2 and rotated by the rotating shaft 24,
5 heated. The raw material gas is introduced from the gas supply port 26, passes through a rectifying hole (not shown) provided in the rectifying plate 27, and is supplied to the film-forming substrate 22 in a rectified manner. The source gas is decomposed and / or reacted to form a film. The raw material gas and the reaction product gas which have not contributed to the reaction pass through the exhaust port 28 to the reaction furnace 21.
It is discharged outside.

In this apparatus, a uniform gas flow is formed on the surface of the substrate 22 by rectifying the gas flow through the rectifying plate 27, and the gas vortex is eliminated. It is described to obtain a quality membrane.

The Japan Institute of Metals, Vol. 41 (1977)
Year) pages 358-367 show that Si ₃
A CVD apparatus capable of obtaining N ₄ has been reported. This CV
In the D apparatus, as shown in FIG. 4, a substrate 32 on which a film is to be formed is fixed in a reaction furnace 31 by a graphite socket 33, an electric current is supplied to an electrode 34, and the substrate 32 for a film is directly heated by 1100 by heating. ~ 1500C.

In this apparatus, a raw material gas is introduced from two gas supply ports 35 and 36 and reacts on the substrate 32 to form Si ₃ N _4, while unreacted gas and reaction product gas are exhausted. It is discharged from the mouth 37. This apparatus performs high-speed film formation at a rate of 2 mm / h by directly heating the film-forming substrate 32 by applying current.

[0010]

However, in the CVD apparatus shown in FIG. 4, since the substrate 32 to be film-formed is directly energized, the productivity is low because each product is energized. There is a problem that the structure is inappropriate for a product having a complicated shape.

The raw material gas is supplied to two gas supply ports 35,
36, the film is strongly influenced by the gas flow of the gas supply port 36 close to the substrate 32 to be formed, and the film is thicker at the portion where the raw material gas is blown, the film becomes thinner at the periphery, and the film thickness becomes smaller. There was a difference and it was easy to be uneven.

On the other hand, according to Japanese Unexamined Patent Publication No. 11-67675 in FIG. 3, in FIG. 3, a gas flow is controlled by using a flow straightening plate 27, and the film thickness is reduced by a furnace structure for preventing generation of a gas vortex. Although the uniformity is improved and the crystallinity is improved, the film supply speed is low because the gas supply port 26 is separated from the film formation substrate 22, and film formation on a portion other than the film formation substrate can be performed. Since there are many unreacted gases, there is a problem that the use efficiency of the raw material gas is low and the cost is increased. In particular, the cost is increased due to the reduced use efficiency in the case of a complex-shaped substrate, and it is almost impossible to form a uniform film with the apparatus shown in FIGS.

SUMMARY OF THE INVENTION An object of the present invention is to provide a CVD apparatus capable of increasing the use efficiency of a raw material gas, and in particular, reducing the cost by forming a film at a high speed even on a large ring-shaped substrate.

[0014]

According to the present invention, there is provided a film forming apparatus, comprising: a reaction vessel; a support provided in the reaction vessel for supporting a ring-shaped substrate; and means for heating the ring-shaped substrate. A gas for guiding a reaction gas from the center of the ring-shaped substrate to the inner peripheral surface and / or the upper surface of the ring-shaped substrate in a space located inside the ring-shaped substrate. And an introduction means. In particular, the gas introducing means includes a pair of flat plates arranged in parallel inside the ring-shaped base, and a gas introducing pipe for introducing gas into the center of one of the flat plates. Is preferred. With this structure, it is possible to prevent film formation on a portion other than the ring-shaped substrate, and to promote the CVD reaction intensively on the ring-shaped substrate. As a result, the film formation speed can be increased.

Further, it is preferable that the flat plate contains any one of graphite fiber, alumina fiber, silicon carbide fiber and quartz glass. By selecting these materials, the effect of preventing film formation on portions other than the ring-shaped substrate can be enhanced.

Further, the heating means is preferably high-frequency induction heating. In particular, the number of turns of the high-frequency induction coil used for high-frequency induction heating is 1-2, and a catalyst body is provided inside the ring-shaped substrate. It is preferable that the high-frequency induction coil is installed to heat the catalyst body and the ring-shaped substrate at the same time. That is, by using the high-frequency induction heating device, only the ring-shaped substrate is heated, and the CVD reaction is concentrated on the substrate surface, so that the use efficiency of the source gas can be further increased.

The film forming method of the present invention uses the film forming apparatus of the present invention to form a film on at least the inner peripheral surface and / or the upper surface of the ring-shaped base placed on the surface of the support. It is characterized in that the use efficiency of the source gas is enhanced, high-speed film formation is possible, and the film formation cost can be reduced.

In particular, a liquid raw material composed of a compound containing silicon and chlorine is vaporized, and a reaction gas is used to form a liquid raw material of 1300-1.
It is preferable to heat at a temperature of 700 ° C. to form a silicon carbide film at a deposition rate of 0.3 mm / h or more. Thus, a silicon carbide film having a thickness of 1 mm or more can be manufactured in a short time and at low cost.

It is preferable that the ring-shaped substrate is at least one selected from graphite, silicon carbide, silicon nitride and alumina. By selecting these materials, the effect of preventing film formation on portions other than the ring-shaped substrate can be enhanced.

It is preferable that the ratio of the inner diameter to the outer diameter of the ring-shaped substrate is 0.3 to 0.99. When this condition is satisfied, the raw material use efficiency is increased, and the cost reduction is particularly remarkable.

Further, it is preferable that the heating means is high-frequency induction heating, and that the high-frequency frequency used for the high-frequency induction heating is f, the resistivity of the substrate is ρ, the substrate permeability is μ, and the substrate width is When w, 2.012ρ ≦
It is preferable to satisfy fμw ≦ 10.06ρ. By using the high-frequency induction heating apparatus and satisfying the above conditions, it is possible to efficiently heat only the ring-shaped substrate, promote the CVD reaction on the substrate, and further increase the use efficiency of the source gas.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A film forming apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a schematic layout view of a film forming apparatus of the present invention. A reaction vessel 1 is composed of a flange 2 and a wall body 3, and a ring-shaped substrate 5 is provided on a support 4 made of a heat insulating material. It is placed.

The ring-shaped substrate 5 is provided in a space formed by a pair of disk-shaped flat plates 6, and the raw material gas is supplied through a gas inlet 7 and is installed at the tip of the gas inlet 7. In the space formed by the pair of flat plates 6, the gas flows radially from the center to the outer periphery.

A high-frequency induction heating coil 8 for heating the ring-shaped substrate 5 is provided around the reaction vessel 1. As indicated by the arrow in the figure, the gas inlet 7
After being reacted, the raw material gas introduced into the ring-shaped substrate 5 through the space between the flat plates 6 is discharged from the gas exhaust port 9 as waste gas.

The reaction vessel 1 has a flange 2 in FIG.
And the wall 3, and their joints are vacuum-sealed with viton rubber or the like. The flange 2 may be made of a general metal material such as stainless steel, but when a corrosive gas such as a chlorine-based gas is used, it is preferable to use a corrosion-resistant material such as SUS316. Further, in order to avoid an increase in the temperature of the vacuum seal portion, the flange 2 is preferably cooled by water cooling or the like. The wall 3 is made of a material that hardly absorbs high frequency, for example, quartz glass, silicon nitride,
Ceramics such as alumina, aluminum nitride, YAG, and spinel can be used.

The above-mentioned heat insulating material has an effect of limiting a portion having a temperature sufficient for forming a film to the vicinity of the ring-shaped substrate 5. Although only one ring-shaped substrate 5 shown in FIG. 1 is mounted on the support 4, when a film is formed on a plurality of ring-shaped substrates, for example, a ring is used with bolts or the like. For example, a method of fixing the side surface of the substrate to the support 4 is required.

The heat insulating material constituting the support 4 is preferably a material having a large thermal resistance. For example, a material using graphite or ceramics can be used, and a fibrous material such as an oxide fiber heat insulating material or graphite fiber can be used. It is preferred that they contain. In particular, a heat insulating material using graphite fibers is preferable in terms of cost.

When a heat insulating material using conductive graphite fibers is used, the support 4 itself may be heated at a high frequency depending on the frequency and output, and when the temperature of the support 4 becomes higher than the film forming temperature. A film is formed on the surface of the support 4. Therefore,
In order to make it difficult for the current induced by the high frequency to flow on the surface, it is preferable to provide a plurality of slits in a direction perpendicular to the surface of the high frequency induction coil 8 on the surface of the heat insulating material constituting the support 4. The number of slits and the depth may be determined in consideration of the operating frequency and the allowable temperature.

The temperature of the support 4 may increase with the passage of time due to the heat of the ring-shaped substrate 5 heated by the high-frequency induction heating or by itself being heated by the high-frequency induction heating. In such a case, in order to lower the surface temperature of the support 4, it is preferable to provide a cooling mechanism such as flowing an inert gas to the surface and / or the inside of the support 4. Thereby, film formation on the surface of the support 4 can be prevented.

The ring-shaped substrate 5 is provided at a position where gas flowing out from between a pair of circular flat plates 6 comes into contact. That is, at least a part of the ring-shaped base 5 is arranged at substantially the same height as the space between the flat plates 6, in other words,
The ring-shaped base 5 and a pair of flat plates 6 are arranged so as to flow from the center of the ring-shaped base toward the inner peripheral surface. If the positional relationship is deviated, the amount of the source gas in contact with the ring-shaped base 5 is reduced, so that the raw material use efficiency is reduced.

The ring-shaped substrate 5 may be installed between a pair of circular flat plates 6, but the ring-shaped substrate 5 generates heat, and the flat plate 6 is heated by the heat.
Is preferably a material having high heat insulating properties.

The material of the flat plate 6 is desirably selected to have a lower electrical conductivity or thermal conductivity than the ring-shaped substrate 5. By using such a material, the flat plate 6
Can be prevented, the film forming reaction on the ring-shaped substrate 5 can be promoted, and the raw material use efficiency can be improved.

For example, the material of the ring-shaped substrate 5 is at least one selected from graphite, silicon carbide, silicon nitride and alumina, and the material of the flat plate 6 is graphite fiber, alumina fiber,
The above conditions can be satisfied by selecting any one of silicon carbide fiber and quartz glass.

The shape of the ring-shaped substrate 5 is such that the ratio of the inner diameter to the outer diameter is 0.3 to 0.99, especially 0.5 to 0.9.
7, more preferably 0.7 to 0.95. As a result, the use efficiency of the source gas is increased, the cost reduction effect is large, and stable film formation can be performed.

The gas inlet 7 can be made of SUS316 which has high corrosion resistance and is easy to process. However, when the temperature rises due to high-frequency induction heating, it is preferable to use ceramics such as alumina or silicon nitride, quartz glass, or the like at least at the end of the gas inlet 7.

The high-frequency induction coil 8 is for heating the ring-shaped base 5. In the high-frequency induction heating, a current is applied directly to the surface of the ring-shaped substrate 5 to directly heat the same, so that the heating efficiency of the ring-shaped substrate 5 is improved as compared with other portions, so that the temperature of the ring-shaped substrate 5 is selectively increased. Thus, a film forming reaction on the ring-shaped substrate 5 can be promoted, and a high raw material use efficiency can be obtained.

In the high-frequency induction heating, the penetration depth of the surface current varies depending on the frequency. Therefore, in order to increase the heating efficiency of the ring-shaped substrate 5, it is necessary to select a frequency that matches the shape of the ring-shaped substrate 5. The frequency f preferably satisfies 2.012ρ ≦ fμw ≦ 10.06ρ, where ρ is the resistivity of the substrate to be heated, μ is the magnetic permeability of the substrate, and w is the width of the substrate.

The height of the high-frequency induction coil 8 affects the efficiency of converting high-frequency energy into heat. Therefore, when heating a thin base such as a ring, the high-frequency induction coil 8 is also formed into a thin ring, and the number of turns is 1-2.
And the high frequency induction coil 8 is heated by the ring-shaped substrate 5
By arranging them at substantially the same height, the heating efficiency of the ring-shaped substrate 5 can be increased.

A general vacuum pump can be used for exhausting the gas. For example, an oil rotary pump, a mechanical booster pump, a dry pump, a turbo molecular pump, a water ring type pump, or the like can be used according to the degree of vacuum.
Among these, when a film is formed under reduced pressure and a large amount of halide is used as a raw material, it is preferable to provide a pump for initial evacuation and a pump for CVD separately.

Further, according to the film forming method of the present invention, a film is formed using the film forming apparatus of the present invention described above, and the efficiency of the raw material is high even for relatively large parts. The film can be formed at high speed, and the product cost can be improved.

As an example, a method for forming a silicon carbide film using the apparatus shown in FIG. 1 will be described.

First, the inside of the reaction vessel 1 is evacuated by a vacuum pump, hydrogen or an inert gas is introduced and maintained at a predetermined pressure, and high-frequency power is applied to the high-frequency induction heating coil 8 to heat the ring-shaped substrate 5. I do.

Next, the ring-shaped substrate 5 is held at a predetermined temperature, and a raw material gas is introduced from a gas inlet 7 into a central portion in a space surrounded by a pair of flat plates 6, and the gas is introduced into the ring-shaped substrate. The ring-shaped substrate 5 flows toward the peripheral surface and / or the upper surface.
And a film is formed on the surface by a CVD reaction. The reaction product gas generated by the reaction with the unreacted gas is supplied to the gas outlet 9
Is more exhausted. In FIGS. 1 and 2, the flow of gas is indicated by arrows.

The CVD reaction occurs on the surface of the ring-shaped substrate 5, and a film is formed on at least one of the inner peripheral surface, the upper surface, and the outer peripheral surface of the ring-shaped substrate 5. In particular, it is preferably formed on the inner peripheral surface and / or the upper surface.

In forming the silicon carbide film, for example,
A ring-shaped base 5 made of high-purity carbon having a ring shape with an inner diameter of 120 mm and an outer diameter of 210 mm is placed on a support 4 made of a carbon-molded heat insulating material as shown in FIG. Install and place it so that it is on the extension of the enclosed space.

Then, the pressure inside the reaction vessel 1 is reduced by a general vacuum pump such as an oil rotary pump, a mechanical booster pump or a dry pump. Then, for example, when the degree of vacuum becomes 1 Pa or less, hydrogen gas is introduced, the pump is switched to a water-sealed pump, and the pressure in the reaction vessel 1 is maintained at, for example, 0.1 to 20 kPa. Here, a water-sealed pump is used because it is easy to treat HCl generated by CVD, but a desired pump can be used depending on the raw materials, processing equipment, and operating pressure.

Next, high-frequency power is applied to the high-frequency induction coil 8 while flowing hydrogen gas to heat the ring-shaped substrate 5. After the temperature of the ring-shaped substrate 5 reaches 1300 to 1700 ° C., a mixed gas of hydrogen and the raw material gas methyltrichlorosilane is introduced from the gas inlet 7 to form a silicon carbide film.

Here, the mixed gas refers to a single gas or a mixed gas containing silicon and carbon. For example, as a single gas, methyltrichlorosilane (CH ₃ SiCl ₃ , hereinafter MT)
S), silicon tetrachloride (SiC)
l ₄ ), SiHCl ₂ , SiH ₂ Cl, SiH ₄ , (C
H ₃ ) ₄ Si, (CH ₃ ) ₂ SiCl ₂ , (CH ₃ ) ₃ SiC
1, a gas containing silicon such as MTS and a gas containing carbon such as methane.

Among the above gases, a gas containing silicon and chlorine is preferable as a gas containing silicon from the viewpoints of safety and high-speed film formation. In particular, MTS is preferred. Further, (CH ₃ ) ₄ Si is preferably used from the viewpoints of corrosion resistance, high volatility and easy handling.

The raw material gas does not need to be a gas at normal temperature, but may be a liquid or a gas as long as a vapor pressure is generated by heating. In particular, those that generate a vapor pressure higher than the film forming pressure at a temperature of 100 ° C. or less are preferable.

Then, the CVD temperature is set to 1300 to 1700.
° C, particularly preferably 1400 to 1600 ° C, and the deposition rate is preferably 0.3 mm / h or more. Thereby, a silicon carbide film having a thickness of 1 mm or more can be easily obtained at low cost.

By removing the ring-shaped substrate 5 mechanically or chemically, a bulk material of silicon carbide can be manufactured in a short time and at low cost.

FIG. 2 shows another example of the film forming apparatus of the present invention. A reaction vessel 11 is composed of a flange 12 and a wall 13 and has a support 14 made of a heat insulating material inside. A ring-shaped base 15 is provided.

Further, the ring-shaped substrate 15 is provided in a space formed by a pair of disk-shaped flat plates 16, and a raw material gas is supplied to a central portion through a gas inlet 17 and is installed at a tip of the gas inlet. In the space formed by the pair of flat plates 16, the gas flows radially from the center toward the outer peripheral portion, that is, toward the inner peripheral surface of the ring-shaped base 15.

Further, a high frequency induction coil 18 for heating the ring-shaped base 15 is provided around the reaction vessel 11. As indicated by the arrow in the figure, the raw material gas introduced from the gas inlet 17 and flowing through the space between the flat plates 16 to the ring-shaped substrate 15 is discharged from the gas outlet 19 as a waste gas after the reaction. You.

The catalyst body 20 is provided in the space formed by the flat plate 16 or outside the flat plate. The catalyst body 20 is installed in the space formed by the pair of flat plates 16 or outside the flat plates, and is induction-heated together with the ring-shaped base at high frequency. Absent.

Since the catalyst 20 has a high effect of activating a gas and accelerating a film forming reaction, W and / or Ta are preferable. Further, the shape of the catalyst body 20 is preferably a wire, and a stranded wire made by knitting a plurality of wires or a mesh-shaped porous body formed by knitting the stranded wire can be used.

[0058]

EXAMPLE 1 A silicon carbide film was formed on a ring-shaped substrate 5 using the film forming apparatus of the present invention shown in FIG.

The flange 2 constituting the above device is made of SUS
The wall body 3 is made of quartz glass and is water-cooled. The ring-shaped substrate 5 has an outer diameter of 210 mm and an inner diameter of 1 mm.
90mm, 10mm thick high purity graphite, outer diameter 26
The portion on which the ring-shaped substrate 5 is mounted, having a diameter of 0 mm and an inner diameter of 150 mm, is disposed on a support 4 made of a graphite felt molded body having an inner diameter of 220 mm.

The gas inlet 7 is made of quartz glass, and a pair of flat plates 6 each having a diameter of 185 mm and a thickness of 5 mm are integrally provided at the tip thereof. The gas flows into the space and flows from the center of the flat plate 6 toward the outer periphery, so that the gas hits the inner peripheral surface of the ring-shaped substrate 5 which is the film forming surface. The distance between the flat plates 6 is 10 m.
m.

The inside of the reaction vessel 1 was evacuated with a rotary empty pump until the degree of vacuum reached 1 Pa or less, and hydrogen gas was introduced at a flow rate of 5 l / min. The pump was switched to a water ring pump, the pressure was maintained at 1 kPa, and high frequency power was applied to the high frequency induction coil 8. The high frequency is 20kHz
The output was adjusted so that the temperature of the ring-shaped substrate 5 became 1500 ° C. The desired temperature was reached 10 minutes after the start of heating.

Subsequently, a mixed gas of methyltrichlorosilane gas and hydrogen gas as a raw material gas was 1.5 l /
The flow rate was 10 min / min, and the pressure in the reaction vessel 1 was adjusted to about 2.7 kPa. After 3 hours, introduction of the methyltrichlorosilane gas was stopped, and then heating was stopped.

After the completion of the film formation, the weight of the ring-shaped substrate 5 was measured, and the weight increase was defined as the amount of CVD SiC, and the raw material use efficiency was calculated assuming that the case where methyltrichlorosilane was completely converted to SiC was 100. . Further, the ring-shaped substrate 5
At the same time, the silicon carbide film was broken into about eight equal parts, each cross section was photographed with a microscope, the thickness of the film formed on the film formation surface was measured, and the average value was calculated.

As a result, the raw material use efficiency was 20%, and the film thickness was 3.0 mm. Example 2 A silicon carbide film was formed using the film forming apparatus shown in FIG. The gas inlet 17 is made of quartz glass.
A pair of flat plates 16 each made of graphite and having a thickness of 5 mm and a thickness of 5 mm were arranged at intervals of 10 mm.

A W mesh was used as the catalyst body 20. The W mesh is a 50 mesh having a wire diameter of 0.05 mm, and is 90 mm from the center in a gap formed by the flat plate 16.
In the position, it was arranged in a direction perpendicular to the flat plate 16 so as to close the gap. Further, in order to form the film formation surface on the upper surface of the ring-shaped substrate 15, the upper surface of the ring-shaped substrate 15 is arranged so that the height of the upper surface is 3 mm below the upper plate of the pair of flat plates 16, and the reaction gas is supplied to the ring-shaped substrate 15. The upper surface of Other structures and evaluation methods were the same as those in Example 1.

As a result, the raw material use efficiency was 30%, and the film thickness was 3.5 mm. Comparative Example A film forming test was performed using the film forming apparatus shown in FIG. The same ring-shaped substrate 5 as in Example 1 was placed on a rotating substrate holder 23 made of high-purity graphite as a specific film-forming substrate 22 at a speed of 20 rpm.
m. The inside of the reaction furnace 21 was evacuated with a rotary vacuum pump until the degree of vacuum reached 1 Pa or less, and hydrogen gas was introduced at a flow rate of 5 l / min. The pump was switched to a water-sealed pump, and the pressure was maintained at 1 kPa, and the ring-shaped substrate 5 was heated to 1500 ° C. by the graphite heater 25.

Subsequently, a mixed gas of methyltrichlorosilane gas and hydrogen gas was used as a raw material gas at 1.5 l / l.
The flow rate was 10 min / min and the pressure inside the reaction furnace 21 was adjusted to about 2.7 kPa. After 3 hours, introduction of the methyltrichlorosilane gas was stopped, and then heating was stopped. After the film formation was completed, the raw material use efficiency and the average film thickness were determined in the same manner as in Example 1.

As a result, the raw material use efficiency was 3%, and the film thickness was 0.5 mm.

[0069]

According to the present invention, it is possible to provide a CVD apparatus capable of improving the use efficiency of the source gas and, in particular, reducing the cost by forming a film at a high speed on a large part of a ring-shaped substrate.

[Brief description of the drawings]

FIG. 1 is a schematic layout diagram of a film forming apparatus of the present invention.

FIG. 2 is a schematic layout view of another film forming apparatus of the present invention.

FIG. 3 is a schematic layout view of a conventional film forming apparatus.

FIG. 4 is a schematic layout view of another conventional film forming apparatus.

[Explanation of symbols]

 1, 11 ... reaction vessel 2, 12 ... flange 3, 13 ... wall 4, 14 ... support 5, 15 ... ring-shaped substrate 6, 16 ... flat plate 7, 17 ... Gas inlet 8,18 ... High frequency induction coil 9,19 ... Gas exhaust

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Wang Ameso 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima F-term in the Kyocera Research Institute (reference) 4K030 AA03 AA06 AA09 BA37 CA01 CA05 CA11 EA06 FA10 JA10 JA12 KA24 KA46

Claims (10)

[Claims] 1. A film forming apparatus comprising: a reaction vessel; a support provided in the reaction vessel for supporting a ring-shaped substrate; and means for heating the ring-shaped substrate. Gas introducing means for guiding a reaction gas from the center of the ring-shaped substrate to the inner peripheral surface and / or the upper surface of the ring-shaped substrate in a space located inside the ring-shaped substrate. Membrane equipment. 2. The gas introducing means comprises a pair of flat plates arranged in parallel inside a ring-shaped base, and a gas introducing pipe for introducing a gas into the center of one of the flat plates. The film forming apparatus according to claim 1. 3. The film forming apparatus according to claim 1, wherein said flat plate contains any one of graphite fiber, alumina fiber, silicon carbide fiber and quartz glass. 4. A film forming apparatus according to claim 1, wherein said heating means is high-frequency induction heating. 5. A high-frequency induction coil used for high-frequency induction heating has a number of turns of 1 to 2, and a catalyst is disposed inside the ring-shaped substrate, and the high-frequency induction coil connects the catalyst and the ring-shaped substrate. The film forming apparatus according to claim 4, wherein heating is performed simultaneously. 6. A film is formed on at least an inner peripheral surface and / or an upper surface of a ring-shaped substrate placed on a surface of the support by using the film forming apparatus according to any one of claims 1 to 5. A film forming method. 7. A liquid raw material comprising a compound containing silicon and chlorine is vaporized and used as a reactant gas to produce a liquid material of 1300 to 1700.
7. The film forming method according to claim 6, wherein the silicon carbide film is formed by heating at a temperature of ° C. at a deposition rate of 0.3 mm / h or more. 8. The ratio of the inner diameter to the outer diameter of the ring-shaped substrate is 0.3 to 0.99.
Or the film forming method according to 7. 9. The film forming method according to claim 6, wherein said ring-shaped substrate is at least one selected from graphite, silicon carbide, silicon nitride and alumina. 10. When the frequency of the high frequency wave used for the high frequency induction heating is f, the resistivity of the substrate is ρ, the magnetic permeability of the substrate is μ, and the width of the substrate is w, 2.012ρ ≦ fμw ≦ 10.06.
10. The film forming method according to claim 6, wherein ρ is satisfied.