JP2002252176A - Cvd device and thin-film manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CVD device, which can form an equal thin film on a substrate, and a thin-film manufacturing method using it. SOLUTION: When a gas, after having stacked a thin film on the substrate 14 moves away from a heating element 13, the gas moves away from the heating element 13, being led in the horizontal direction or under to the outside of an inner tube 11 by an outer tube 10, whereby the gas is cooled and the density increases, but this gas will not flow back into the inner tube 11, and the disorder of the gas caused by the natural convection in the vicinity of the heating element 13 is suppressed, and a flow parallel with the face of the substrate 14 is made, so that the supplying of equal gas to the substrate 14 becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a CVD apparatus for depositing a thin film on a substrate and a method for producing a thin film using the same.

[0002]

2. Description of the Related Art Semiconductors containing light elements such as silicon carbide and gallium nitride have excellent chemical resistance to acids and alkalis, as well as high durability to high energy rays, and are excellent in durability. Further, since it has a high dielectric breakdown voltage and does not lose its properties as a semiconductor even at high temperatures, it is also used as a material for power devices and high temperature devices.

In order to manufacture a device using such a semiconductor material, it is necessary to obtain a high-quality single-crystal thin film free from lattice defects such as large defects (micropipes and the like) and stacking faults. Are manufactured using a CVD apparatus.

[0004] As the CVD apparatus, for example, a horizontal hot zone CVD apparatus 90 as shown in FIG. 3 and a vertical hot zone CVD apparatus 91 as shown in FIG. 4 are well known. The horizontal hot zone CVD apparatus 90 is used for the reaction vessel 7.
0, a gas introduction nozzle 15 is provided on one of the opposed side surfaces of the reaction vessel 70, and a gas discharge nozzle 16 is provided on the other side.
And R for inductively heating the heating element 13 from outside the reaction vessel 70.
And an F work coil 20. In addition, the reaction vessel 7
A heat insulating material (heat insulating means) 12 for preventing heat radiation from the heating element 13 to the outside is provided in the inside 0, and a reflection plate 31 for preventing heat radiation from the reaction container 70 to the outside is provided outside the reaction vessel 70.
And a cooling pipe 32 for cooling the reflection plate 31.

A vertical hot zone CVD apparatus 91
Is a vertical hot zone CVD apparatus 90 in which a lower nozzle of a reaction vessel 70 is a gas introduction nozzle 15 and an upper nozzle is a gas discharge nozzle 16.

For example, in the production of a silicon carbide single crystal thin film, a source gas such as silane or propane is introduced into a reaction vessel 70 from a gas introduction nozzle 15 and heat generated by induction heating by an RF work coil 20. The substrate 14 is placed on the body 13 at a temperature of 1200 ° C. or higher, usually 1500 ° C.
The substrate is heated to about ° C., and the introduced gas is reacted on the substrate 14 to deposit a silicon carbide film on the substrate 14.

[0007]

However, such C
When depositing a thin film using a VD apparatus, the following problems have occurred. In the case of the horizontal hot zone CVD apparatus 90, when the gas introduced from the gas introduction nozzle 15 is heated close to the heating element 13, the volume expands and the density decreases, and the gas rises as shown in FIG. Cause natural convection. In addition, before the gas after the reaction leaves the heating element 13 and reaches the gas discharge nozzle 16, the gas is generated by the heating element 13.
The gas was cooled by moving away from the reactor, the volume shrank and the density increased, and the gas descended and caused natural convection as shown in FIG.

Also, in the case of the vertical hot zone CVD apparatus 91, the gas after the reaction rises and the gas discharge nozzle 16
In the same manner, the gas is cooled down and descends, causing natural convection as shown in FIG. 2C, and the gas flow in the reaction vessel 70 is disturbed.

When the gas flow in the reaction vessel 70 is disturbed, the supply of the raw material gas to the substrate 14 becomes uneven, and the thin film formed on the substrate 14 becomes uneven.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a CVD apparatus capable of forming a uniform thin film on a substrate by suppressing turbulence of a gas flow in a reactor, and a thin film using the same. It is an object of the present invention to provide a method for producing the same.

[0011]

SUMMARY OF THE INVENTION A CVD apparatus according to the present invention is a CVD apparatus for transporting a gas onto a substrate and causing it to react to deposit a thin film on the substrate. A heating element installed inside the inner tube to heat the substrate, and a heating element installed above the heating element to guide the upward flow of the gas passing through the heating element to the outside of the inner tube in a horizontal or lower direction and to discharge the gas, A first rectifying unit configured to form a gas flow parallel to the surface of the substrate with respect to the substrate;

According to the CVD apparatus of the present invention, when the gas after depositing the thin film on the substrate moves away from the heating element, the gas is guided to the outside of the inner tube by the first rectifying means in a horizontal or lower direction. Therefore, the gas that is cooled and increases in density by moving away from the heating element does not flow back into the inner tube, and the turbulence of the gas flow due to natural convection near the heating element is suppressed, and a flow parallel to the substrate surface is formed.

Here, the first straightening means forms an outer pipe extending downward, having a diameter larger than that of the inner pipe, and being spaced apart from the inner pipe by a predetermined distance, and covering the inner pipe in opposition to the upward flow of gas. Is preferred. Thereby, the gas is more appropriately discharged through the gap between the inner pipe and the outer pipe.

Preferably, the heating element is installed on the inner surface of the upper portion of the inner tube in parallel with the inner tube, and holds the substrate in parallel with the inner tube. As a result, the above function is sufficiently exhibited with a simple configuration.

Further, it is preferable that the heating element is provided in the inner pipe via a heat insulating means. As a result, heat from the heating element is not transmitted to the outside of the inner tube, so that the gas guided to the outside of the inner tube is more smoothly discharged without being heated.

The heating element has a predetermined angle including a surface perpendicular to the inner tube with respect to the substrate, and further includes second rectifying means in the inner tube for rectifying the gas to flow in parallel on the substrate. Is preferred.

Accordingly, even when the substrate is installed at an angle including the vertical with respect to the inner tube, the gas flows in parallel with the substrate, so that extra turbulence of the gas near the substrate is suppressed and The gas is efficiently supplied to the substrate.

The heating element is a horizontal plate having a through-hole formed therein, and an introduction pipe for introducing gas into the through-hole is connected to a lower portion of the through-hole. It is preferable to include a rectifier disposed so as to face the introduced gas so that the gas introduced via the gas flows in parallel to the horizontally installed substrate.

Since the heating element is horizontal, it is easy to install many substrates on the heating element, and gas is easily introduced between the substrate and the rectifier by the introduction pipe. This suitably forms a gas flow parallel to the substrate.

Further, it is preferable to provide a rotating means for rotating the heating element in the horizontal direction. Thus, the gas supplied to the substrate on the heating element is made uniform, and a thin film can be more uniformly deposited.

It is preferable that the introduction pipe further preheats the gas. As a result, the gas before reaching the substrate is preheated, so that the temperature rise of the source gas near the substrate is reduced, and further disturbance of the gas near the substrate is suppressed.

In addition, the heating element includes a high-frequency induction from the outside,
Alternatively, heat is preferably generated by energization. Thus, the CVD apparatus is simply configured, and the substrate is suitably heated by heat generation.

Further, a method of manufacturing a thin film according to the present invention is characterized in that a silicon carbide or nitride semiconductor thin film is deposited on a substrate using the above-described CVD apparatus. According to the manufacturing method of the present invention, since the CVD apparatus according to the present invention is used, a uniform silicon carbide or nitride semiconductor thin film can be easily obtained.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Preferred embodiments of a CVD apparatus and a thin film manufacturing method using the same according to the present invention will be described in detail. In addition,
In the description of the drawings, the same or corresponding elements have the same reference characters allotted, and overlapping description will be omitted.

FIG. 1 shows a CVD apparatus 100 according to the first embodiment.
FIG. The CVD apparatus 100 reacts a raw material gas in the vicinity of the substrate 14 to deposit a thin film such as a semiconductor on the surface of the substrate 14, and includes a heating element 13 for heating the substrate 14, and a heating element 13 in which the heating element 13 is installed. A tube 11, an outer tube (first rectifying means) 10 covering the inner tube 11 from outside, and an RF for heating the heating element 13 from the outside of the outer tube 10 by high-frequency induction heating
And a work coil 20.

The inner tube 11 is a vertically arranged circular tube made of quartz and has an open upper end and a lower end closed by a lower flange 18 having a gas introduction nozzle 15.

The outer tube 10 is a quartz tube whose upper end is closed in a dome shape and whose diameter is larger than that of the inner tube 11. The outer tube 10 has a predetermined gap 19 in the radial direction between the outer tube 10 and the inner tube 11, covers the inner tube 11 from above, and has a lower end fixed to the lower flange 18. Also,
A gas discharge nozzle 16 is formed by the lower end of each of the inner tube 11 and the outer tube 10.

The heating element 13 is a graphite plate coated with silicon carbide, and is induction-heated by an external RF work coil 20. The heating element 13 is fixed to an upper portion of the inner surface of the inner tube 11 via a heat insulating material (insulation means) 12 for preventing heat of the heating element 13 from being transmitted to the inner tube 11 side. The substrate 14 is held in close contact with the surface of the heating element 13 such that the surface of the substrate 14 is parallel to the inner tube 11.

The RF work coil 20 generates a high-frequency magnetic flux, thereby inducing an eddy current in the heating element 13 and causing the heating element 1 to generate Joule heat due to the eddy current.
3 is exothermic. Then, the heating element 13 heats the substrate 14 on the heating element 13 to a maximum temperature of about 2200 ° C. by heat conduction. The output of the RF work coil 20 is controlled based on the temperatures of the substrate 14 and the heating element 13 measured by a radiation thermometer (not shown), and the temperature of the substrate 14 is maintained at a desired temperature.

The outer tube 1 is located outside the RF work coil 20.
There is provided a reflector 31 for preventing radiant heat radiated to the outside through the zero to escape, and a cooling pipe 32 installed outside the reflector 31 for cooling the reflector 31 with water. A fan 3 for cooling the outer tube 10 is provided above the outer tube 10.
5 is provided.

Next, the operation of the CVD apparatus 100 according to this embodiment will be described.

First, while the carrier gas is flowing from the gas introduction nozzle 15, the RF work coil 20 is driven to heat the heating element 13, and the temperature of the substrate 14 on the heating element 13 is set to a predetermined etching temperature. Then, when the temperature reaches the etching temperature, an etching gas is supplied from the gas introduction nozzle 15 to etch the surface of the substrate 14. Thereafter, the substrate 14 is further raised to a predetermined deposition temperature, and a source gas is introduced from the gas introduction nozzle 15.

The introduced raw material gas rises from below in the inner tube 11 and approaches the heating element 13 heated to a predetermined temperature. At this time, the gas is heated and expands, and the density decreases and tends to increase due to buoyancy.
Since the flow direction is the same as the gas flow direction in the inner tube 1, the gas flow near the lower portion of the heating element 13 in the inner tube 11 is hardly disturbed. Then, the source gas is heated to cause a reaction, and a thin film of a desired substance is formed on the substrate 14.

The gas after the reaction flows further upward, and the substrate 1
4 and passes through a region near the heating element 13.
The gas separated from the heating element 13 is cooled by losing the heating source and approaching the dome-shaped portion of the outer tube 10, but the gas is turned downward by the dome-shaped portion of the outer tube 10, The gas is guided to the gap 19 between the inner pipe 10 and the inner pipe 11, descends through the gap 19, and is smoothly discharged from the gas discharge nozzle 16 while being cooled.
For this reason, the heating element 13 caused by the gas cooled down in the inner pipe 11 flowing down and backflow due to the decrease in density.
Disturbance of the gas flow due to natural convection near the upper part is suppressed, and a parallel gas flow is formed on the substrate 14. As a result, the source gas is uniformly supplied to the substrate 14 and reacts, so that a thin film is uniformly deposited on the substrate 14.

Further, a heat insulating material 12 is provided between the heating element 13 and the inner tube 11, and since the heat of the heating element 13 is not transmitted to the gap 19 through the inner tube 11, Is also prevented from being reheated, and is discharged more smoothly.

Although the temperature of the substrate is not particularly limited,
For example, in the case of a nitride semiconductor, the temperature is preferably 900 ° C. or higher, and in the case of silicon carbide, the temperature is preferably 1300 ° C. or higher, more preferably 1500 ° C. or higher. Such high temperature CVD
In this case, the heat convection becomes more remarkable.
According to the D apparatus 100, the turbulence of the gas flow is sufficiently and effectively suppressed, so that a uniform thin film can be obtained.

Next, the CVD apparatus 200 of the second embodiment
Will be described with reference to FIG. The difference between the CVD apparatus 200 of the second embodiment and the CVD apparatus 100 of the first embodiment is that a horizontal heating element (heating element) 41 for heating the substrate 14 while holding the substrate 14 horizontally, and a horizontal heating element 41
And a tube shaft (introduction tube) 40 for preheating the source gas, and a driving device (rotating means) 50 for horizontally rotating the tube shaft 40. A rectifying body (second rectifying means) 36 in which the gas introduced by the tube shaft 40 flows in parallel to the horizontally installed substrate 14 and is induction-heated by the RF work coil 20 similarly to the horizontal heating element 41, and the vicinity of the substrate 14 The second heat insulator 37 is provided below the horizontal heating element 41 to prevent the heat of the substrate 14 from radiating downward, and the rectifier 36 is installed on the rectifier 36 to prevent the heat near the substrate 14 from radiating upward. And a second heat insulating material 38.

The horizontal heating element 41 is a graphite disk coated with silicon carbide, and is disposed horizontally in the inner tube 11. The horizontal heating element 41 includes a plurality of substrates 14.
Can be placed horizontally thereon, and the substrate 14 can be placed vertically or the like.
, A larger number of substrates 14 can be processed at one time. The horizontal heating element 41 is
The substrate 14 is heated by induction heating by the F work coil 20. Further, a vertical through-hole is formed at the center of the horizontal heating element 41, and a tube shaft 40 for introducing a raw material gas from below is connected vertically downward from the horizontal heating element 41 through the through-hole.

The lower end of the tube shaft 40 passes through the lower flange 18 and is rotatably supported by the lower flange 18. The tube shaft 40 has a heater (not shown),
The raw material gas passing through the inside is made to reach the through hole of the horizontal heating element 41 while being preheated to an appropriate temperature. Further, a portion of the tube shaft 40 below the lower flange 18 is connected to a driving device 50, and by rotating the tube shaft 40 at a predetermined speed,
The horizontal heating element 41 on which the substrate 14 is placed rotates.

The rectifying body 36 is provided inside the inner tube 11 for the horizontal heating element 4.
1 and has a gap between the heating element 13 fixed to the inner surface of the inner tube 11 via the heat insulating material 12 and is introduced through a through hole of the horizontal heating element 41. The direction of the flow of the raw material gas is changed so as to flow parallel to the surface of the substrate 14, and the gas that has passed through the substrate 14 moves up the inner tube 11 along the heating element 13 toward the dome-shaped portion of the outer tube 10. To change.

In such a CVD apparatus 200,
The raw material gas introduced from the gas introduction nozzle 15 is
After being preheated inside, it is further heated by the through holes of the horizontal heating element 41 and rises. Then, the raw material gas strikes the flow straightener 36, the flow direction is changed, and flows on the substrate 14 to deposit a thin film on the substrate 14. Thereafter, the gas is heated 13
The gas flows again upward through the gap between the heating element 13 and the rectifier 36, and gas flowing above the inner pipe 11 is turned by the dome-shaped portion of the outer pipe 10, Discharged via 19.

At this time, the CVD apparatus 10 of the first embodiment
0, the discharged gas returns to the inner pipe 11 due to a decrease in density due to cooling and does not cause a backflow or the like.
Since the turbulence of the gas flow in the inside is suppressed, a parallel flow is formed by the rectifier 36 on the substrate 14, and a uniform thin film can be formed on the substrate 14.

Further, by driving the driving device 50 and rotating the horizontal heating element 41 as necessary, the substrate 14 is moved to further uniform the gas concentration, and a more uniform thin film is deposited. It is possible.

Further, since the gas introduced by the pipe shaft 40 is preheated, the temperature fluctuation of the gas in the vicinity of the through hole of the horizontal heating element 41 is reduced, and the turbulence of the gas flow is further suppressed.

The heating element 13 and the heat generating rectifier 3
6, the gas rising between the inner pipe 11 and the flow regulating body 36 is not cooled, so that the turbulence of the gas flow is further suppressed. When the distance between the inner tube 11 and the flow straightening body 36 is short, the heating element 13 may not be provided.

Hereinafter, the CVD apparatus 100 of the above embodiment,
Examples and comparative examples implemented by the present inventor will be described in order to confirm the effects of the present invention.

Example 1 CVD apparatus 1 of the first embodiment
By using the substrate No. 00, a silicon carbide thin film was epitaxially grown on the substrate 14 in the following procedure.

First, 50 mmφ 4H-SiC ｛000
A 1｝ substrate was prepared. This substrate was prepared by slicing an ingot grown by the modified Rayleigh method and polishing it to a mirror surface. The effective donor density obtained from the capacitance-voltage characteristics of the Schottky barrier was 1-3 × 1
0 ¹⁸ cm ⁻³ , and the thickness was 330 μm. Then, the substrate was etched with molten potassium hydroxide at 500 ° C. for 10 minutes. As a result, the micropipe density is 10 to 100.
It was found that defects having a density of about cm ⁻² and a screw dislocation density of 5 × 10 ³ to 2 × 10 ⁴ cm ⁻² were present. Then, the substrate was polished again, mirror-finished, washed sequentially with an organic solvent, aqua regia, and hydrofluoric acid, and then rinsed with deionized water to obtain a substrate 14.

Next, a thin film was deposited on the substrate 14. First, the substrate 14 was set on the heating element 13, and gas replacement and high vacuum evacuation were repeated several times. Next, after the temperature of the substrate 14 was raised to 1300 ° C. while introducing hydrogen as a carrier gas, the substrate 14 was subjected to vapor phase etching with a hydrogen chloride / hydrogen gas for a predetermined time. Next, set the substrate temperature to 15
The temperature was set to 00 ° C., and silane and propane gas were introduced as raw material gases through the gas introduction nozzle 15 to deposit two thin films as follows. First, the effective donor density is 3-4 × 10 ¹⁷ cm
The n-type SiC buffer layer of ^-3 to 2.6μm deposited, then the n-type active layer of the effective donor density 1 to 2 × 10 ¹⁶ cm ^-3 was 12μm deposited. Here, the control of the n-type conductivity was performed by adding nitrogen gas during the deposition. Table 1 shows details of the growth conditions.

[Table 1]

(Comparative Example 1) A conventional vertical hot zone CVD apparatus 9 having no outer tube 10 and allowing gas to flow from bottom to top
Substrate 1 in the same manner as in Example 1 except that
4 was epitaxially grown on a silicon carbide thin film.

Here, the surface of the grown silicon carbide single crystal thin film was observed with a differential interference optical microscope.
The entire surface of the thin film obtained in the above was in a mirror state. On the other hand, the surface of the thin film obtained in Comparative Example 1 was clouded on the gas outlet side. When the uniformity of the film thickness of the thin film was compared, the variation in the horizontal direction of the film thickness of the thin film obtained in Example 1 was within 3%, whereas the film thickness of the thin film obtained in Comparative Example 1 was less than 3%. In the horizontal direction was 7% or more.

As a result, it has been confirmed that the present invention can provide a CVD apparatus capable of forming a uniform thin film on the substrate 14 while suppressing disturbance of the gas flow in the CVD apparatus.

(Example 2) The CVD apparatus 2 of the second embodiment
Under the conditions shown in Table 2, a 50 mmφ 4H—SiC {0001} substrate prepared in the same manner as
An epitaxial growth of a silicon carbide thin film was performed in the same manner as in Example 1 except that the plurality of silicon carbide thin films were simultaneously installed, and without rotating the horizontal heating element 41.

[Table 2]

(Comparative Example 2) Conventional horizontal hot zone CVD apparatus 9 having no inner tube 11 and allowing gas to flow in the horizontal direction
A silicon carbide thin film was epitaxially grown in the same manner as in Example 2 except that 0 (see FIG. 3) was used.

As a result, the central portion of the deposited thin film was a mirror surface in both Example 2 and Comparative Example 2. However, Example 2
The variation in the thickness of the thin film at the center of the six substrates obtained in the above was 5% or less, while the variation in the thickness of the thin film at the center of the six substrates obtained in Comparative Example 2 Was 10%.

According to the present invention, the CVD
It has been confirmed that it is possible to provide a CVD apparatus capable of forming a uniform thin film on the substrate 14 by suppressing turbulence of the gas flow in the apparatus.

Example 3 A silicon carbide thin film was epitaxially grown in the same manner as in Example 2 except that the horizontal heating element 41 was rotated 10 times per minute by the rotation of the tube shaft 40. While the variation in the film thickness at the center of the six substrates obtained in Example 2 was 5% or less, the variation in the film thickness at the center of the six substrates obtained in Example 3 was less than 5%. It was 3% or less.
Thus, it has been confirmed that a more uniform thin film can be deposited by rotating the substrate 14.

It should be noted that the CVD apparatus according to the present invention is not limited to the above embodiment, but can take various modifications.

For example, in the first and second embodiments, the gas is discharged to the outside of the inner tube 11 and downward by the outer tube 10, but the invention is not limited to this. For example, a flat plate may be arranged above the inner tube 11 and gas may be discharged horizontally out of the inner tube 11.

In the first and second embodiments, the inner tube 11 is installed vertically. However, the present invention is not limited to this. For example, the inner tube 11 may be installed at an angle of about ± 30 degrees with respect to the vertical. The operation and effect of the invention can be obtained.

In the first and second embodiments, the heat insulating material 12 is provided so that the heat of the heating element 13 is not transmitted to the gap 19.
However, if the temperature is not so high, it may not be provided, and the inner tube 11 may also serve as a heat insulating material.

In the second embodiment, the substrates 14 are arranged horizontally, but they may be arranged obliquely. In this case, it is necessary to change the shape of the flow rectifier so that the gas flows in parallel with the substrate disposed obliquely (for example, a wedge-shaped shape facing a gas flow introduced from below, A rectifier that allows gas to flow in parallel on the oblique substrate according to the wedge shape).

In the first and second embodiments, the heating element 13, the horizontal heating element 41, or the second heat insulating material 38 generates heat by high-frequency induction from the external RF work coil 20, but is not limited to this. The heat may be generated due to the above.

In the second embodiment, the tube shaft 40 is provided with a heater to preheat the gas. However, the present invention is not limited to this. A part of the tube shaft 40 is made of graphite material and preheated by the RF work coil 20. Alternatively, the tube shaft 40 may be preheated by transmitting the heat of the horizontal heating element 41. Further, the gas before being introduced into the tube shaft 40 may be preheated by another preheating means. Further, when the temperature of the substrate 14 is low or the like, the preheating does not have to be performed.

In the second embodiment, the horizontal heating element 41
Although the drive device 50 for rotating the upper portion is provided, the drive device 50 need not be provided.

In the embodiment of the present invention, a silicon carbide thin film is manufactured. However, a similar effect can be obtained in the manufacture of a thin film of another material, for example, a thin film of a nitride semiconductor or the like. Needless to say.

[0067]

According to the CVD apparatus of the present invention, when the gas after depositing the thin film on the substrate moves away from the heating element, the gas is diverted to the outside of the inner tube by the rectifying means in a horizontal direction or less. The gas, which is guided and cooled by moving away from the heating element and whose density increases, does not flow back into the inner tube. Disturbance of the gas flow due to natural convection near the heating element is suppressed, and a flow parallel to the substrate surface is formed. Thus, a uniform gas can be supplied to the substrate, so that a uniform thin film can be formed on the substrate.

According to the method for producing a thin film of the present invention,
The CVD apparatus of the present invention makes it possible to easily produce a uniform thin film of silicon carbide or a nitride semiconductor.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a CVD apparatus according to a first embodiment.

FIG. 2 is a schematic view illustrating a CVD apparatus according to a second embodiment.

FIG. 3 is a schematic view showing a conventional horizontal hot zone CVD apparatus.

FIG. 4 is a schematic view showing a conventional vertical hot zone CVD apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Outer pipe (1st rectifying means), 11 ... Inner pipe, 12 ... Heat insulating material (Insulating means), 13 ... Heating body, 14 ... Board, 19 ... Gap, 36 ... Rectifying body (2nd rectifying means), 40 ... pipe shaft (introduction pipe), 41 ... horizontal heating element (heating element), 50 ... driving device (rotating means), 100, 200 ... CVD device.

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000005979 Mitsubishi Corporation 2-6-3 Marunouchi, Chiyoda-ku, Tokyo (72) Inventor Hiroshi Shiomi 1-6-19 Haramachi, Suita-shi, Osaka F-term (reference) 4K030 BA37 BA38 FA10 KA04 KA05 KA12 KA24 5F045 AB06 AB14 AC01 AD18 AF02 AF13 BB01 DA53 DQ04 EB13 EB15 EC02 EC09 EE12 EE20 EF13 EK01 EK02 EK07 EK24

Claims (10)

[Claims] 1. A CVD apparatus for transporting a gas onto a substrate to react and deposit a thin film on the substrate, comprising: an inner pipe through which the gas is introduced from below; A heating element that heats the substrate, installed above the heating element, guides an upward flow of gas passing through the heating element to a direction less than horizontal to the outside of the inner tube, and discharges the gas; And a first rectifying means capable of forming a gas flow parallel to the surface of the substrate. 2. The first straightening means extends downward, has a diameter larger than that of the inner pipe, and is spaced apart from the inner pipe by a predetermined distance to cover the inner pipe so as to face the upward flow of the gas. The CVD apparatus according to claim 1, wherein an outer tube is formed. 3. The heating element is installed on an inner surface of an upper portion of the inner tube in parallel with the inner tube, and holds the substrate so as to be parallel to the inner tube. 3. The CVD apparatus according to 1 or 2. 4. The CVD apparatus according to claim 3, wherein said heating element is installed in said inner tube via heat insulating means. 5. A second rectifying means for rectifying the gas so that a surface of the heating element in contact with the substrate has a predetermined angle including perpendicular to the inner tube, and further rectifies the gas to flow in parallel on the substrate. The CVD apparatus according to claim 1 or 2, wherein the inside of the inner tube is provided. 6. The heating element is a horizontal plate having a through-hole formed therein, and an introduction pipe for introducing the gas into the through-hole is connected to a lower portion of the through-hole. The tube, further comprising a rectifier disposed opposite to the introduced gas so that the gas introduced through the through-hole is made to flow parallel to a horizontally installed substrate. 6. The CVD apparatus according to 5. 7. The CV according to claim 6, further comprising rotating means for rotating the heating element in a horizontal direction.
D device. 8. The CVD according to claim 6, wherein the introduction pipe further preheats the gas.
apparatus. 9. The heating element includes a high-frequency induction from outside,
9. The CVD apparatus according to claim 1, wherein the apparatus generates heat when energized. 10. The method according to claim 1, wherein:
A method for producing a thin film, comprising depositing a thin film of silicon carbide or a nitride semiconductor on the substrate.