JP2011171589A - Vapor phase deposition apparatus and manufacturing method of compound semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor phase deposition apparatus which can make a wafer autorotate freely irrespective of the presence or absence of revolution of a susceptor, and moreover can perform vapor phase growth without influencing the rotation of the wafer even if vapor phase growth conditions change in order to make variation in a film thickness of an epitaxial wafer still smaller than before. <P>SOLUTION: The vapor phase deposition apparatus 10 includes a reactor 11, a barrel type susceptor 12 arranged inside the reactor, and a tray 13 arranged on the surface of the susceptor to mount a wafer W, wherein the tray 13 rotates by a rotary shaft which is different from that of the barrel type susceptor 12, the barrel type susceptor 12 rotates by an electric motor 14 for revolution, and the tray 13 rotates by an electric motor 15 for rotation. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vapor phase growth apparatus for disposing a wafer on the surface of a susceptor in a reactor, supplying a source gas into the reactor, and performing vapor phase growth on the surface of the wafer, and a compound semiconductor substrate using the vapor phase growth apparatus It relates to the manufacturing method.

  In a conventional vapor phase growth apparatus, a susceptor is disposed in a quartz glass reactor, a wafer is disposed on the surface of the susceptor, and the source gas is introduced into the reactor while the susceptor is heated to, for example, 600 to 800 ° C. This structure is supplied to allow epitaxial growth on the wafer surface.

A method of performing vapor phase growth using such a vapor phase growth apparatus is called a hydride VPE method (also simply referred to as VPE method), and an obtained epitaxial wafer is a colored light-emitting element that serves as a light source for illumination or a display device. It is used as a material.
In this case, AsH ₃ (arsine), PH ₃ (phosphine), or the like is used as the source gas. H ₂ is used as such a carrier gas for conveying the source gas.

  Here, it is better that the epitaxial wafer obtained by such vapor deposition has a smaller variation in film thickness. However, the limit is about ± 25% in a vapor deposition apparatus that has not been devised for that purpose. It was.

  Recently, however, the variation in the thickness of the epitaxial wafer has been required to be ± 15% or less due to the demand for improved yield and higher quality in the subsequent process. For this reason, various ideas have been made.

  For example, in Patent Document 1, in order to reduce variation in film thickness, a wafer for rotating a susceptor is rotated in conjunction with a motor for rotating a susceptor, whereby the wafer can be revolved and rotated. A vapor phase growth apparatus has been proposed.

Patent Document 2 proposes a vapor phase growth apparatus as shown in FIG.
In this vapor phase growth apparatus 30, when the susceptor 32 disposed in the reactor 31 is rotated by the revolution motor 34, the flow of the raw material gas flowing from the upper side to the lower side of the susceptor 32 is driven by the rotation gas. By receiving by the rotor 35, the tray 33 disposed on the surface of the susceptor 32 in order to mount the wafer W can be rotated.

  By using such a vapor phase growth apparatus to revolve the wafer on the surface of the susceptor to produce an epitaxial wafer, the wafer revolves in the flow of the raw material gas so that the wafer is upstream on the surface of the wafer. Since the downstream can be eliminated, the film thickness variation of the epitaxial wafer can be reduced as compared with a vapor phase growth apparatus that only revolves the wafer.

Japanese Patent Laid-Open No. 1-216521 JP-A-6-295900

However, in the vapor phase growth apparatus described in Patent Document 1, since the rotation speed of the wafer depends on the rotation speed of the susceptor, the rotation speed of the wafer is automatically determined when the rotation speed of the susceptor is determined. There is a problem that the rotation speed of the susceptor cannot be set to an optimum value.
In addition, such a structure has a problem that the wafer cannot be rotated without rotation of the susceptor.

In addition, since the vapor phase growth apparatus described in Patent Document 2 rotates the wafer by the raw material gas flow, there is a problem that the driving torque of the gas driving rotor for rotation is small. And since it is necessary to use a large amount of source gas in order to drive, there also exists a problem that manufacturing cost rises.
Further, the number of rotations of the wafer tends to be saturated, and in the first place, since the number of rotations varies depending on the flow rate of the raw material gas during the vapor phase growth and the temperature in the furnace, it is very difficult to control.

In addition, the wafer cannot be rotated forward or backward, and there is a drawback that the response to the stop is slow.
Moreover, the gas may cause an unintended lowering of the temperature in the lower part of the reactor, and as a result, reaction products (particles) may be generated on the wafer due to cooling of the exhaust gas.
Also, since the center of rotation of the rotation axis for wafer rotation and the rotation axis for revolution need to be the same, either the rotation axis for wafer rotation or rotation is cylindrical with a diameter larger than that of the other rotation axis. This increases the manufacturing cost of the device. The space between the rotating shaft and the rotating shaft becomes a dead space in which gas replacement is difficult, and there is a problem that the operating efficiency and maintainability of the apparatus are lowered.

  The present invention has been made in view of the above problems, and in order to further reduce the variation in the film thickness of the epitaxial wafer, the wafer can be freely rotated regardless of whether or not the susceptor is rotated. An object of the present invention is to provide a vapor phase growth apparatus capable of performing vapor phase growth without affecting the rotation of the wafer even if the vapor phase growth conditions fluctuate, and a method of manufacturing a compound semiconductor substrate using the vapor phase growth apparatus. .

  In order to solve the above problems, in the present invention, a gas phase comprising at least a reactor, a barrel-type susceptor disposed inside the reactor, and a tray disposed on the surface of the susceptor for mounting a wafer. In the growth apparatus, the tray is rotated by a rotation shaft different from the susceptor, the susceptor is rotated by an electric motor for revolution, and the tray is rotated by an electric motor for rotation. A vapor phase growth apparatus is provided.

Thus, by rotating the tray for mounting the wafer by a motor (rotational electric motor) that is different from the electric motor for revolution for rotating the susceptor, the wafer is not affected by the rotation of the susceptor. Can be rotated. Further, since it is driven electrically, the wafer can be rotated without being affected by fluctuations in the vapor phase growth conditions, and the wafer can be freely rotated and revolved during the vapor phase growth.
In other words, since the rotation of the wafer can be freely controlled according to the vapor growth conditions, the rotation of the wafer can be controlled according to the situation, and the film thickness of the vapor growth film is made more uniform than before. Therefore, a vapor phase growth apparatus suitable for the above can be obtained.
In addition, since the susceptor is a barrel type, it is difficult to generate a slip in the vapor growth film, a vapor growth film with less metal contamination and surface defects can be obtained, and an apparatus suitable for manufacturing a high quality vapor growth film It has become.

Here, it is preferable that the revolution electric motor and the rotation electric motor have two rotation axes that do not coincide with each other.
In this way, the rotating shaft of the electric motor for revolution (with the center of the rotating shaft for revolution) and the rotating shaft of the electric motor for rotating (with the center of the shaft of rotating shaft) separated from each other. For example, it is not necessary to use a cylindrical shape having a diameter larger than that of the other rotating shaft for the rotating shaft for wafer revolution or rotation, and a general rod or the like can be used. In addition, dead space or the like is not generated, and it is possible to prevent a decrease in operating efficiency and maintainability.

  The present invention also provides a method for producing a compound semiconductor substrate, wherein a wafer is mounted on the tray disposed on the susceptor using the vapor phase growth apparatus according to the present invention, and the wafer is rotated and revolved. A method of manufacturing a compound semiconductor substrate is provided, wherein a III-V group compound semiconductor is vapor-phase grown on a main surface of the wafer.

  As described above, according to the vapor phase growth apparatus of the present invention, the wafer can be rotated and revolved by an electric motor, and the film thickness of the vapor phase growth film can be made more uniform than in the prior art. Group III-V compound semiconductors grown on the main surface of a wafer using a simple vapor phase growth apparatus have a uniform film thickness as compared with the conventional ones. The yield can be improved, and the manufacturing cost can be reduced.

Here, a ratio (rotation number / revolution number) between the rotation number (revolution number) of the tray rotated by the electric motor for rotation and the rotation number (revolution number) of the susceptor rotated by the electric motor for revolution. 4 to 20 is preferable.
Thus, by setting the ratio of the number of revolutions of the wafer to the number of revolutions of 4 or more, the number of revolutions of the wafer does not become too small compared to the number of revolutions of the wafer, and the film thickness of the compound semiconductor becomes nonuniform. Can be prevented. Moreover, if it is 20 or less, it can prevent that the dust generation by friction of components becomes large, and can manufacture a high quality compound semiconductor substrate.

The ratio is preferably a decimal number instead of an integer.
Thus, by making the ratio of the tray rotation speed (wafer rotation speed) and the susceptor rotation speed (wafer revolution speed) a decimal number instead of an integer, the wafer rotation speed and the rotation speed are synchronized (regularly). Rotation) can prevent the occurrence of a specific level in the film thickness of the compound semiconductor substrate, and a method for manufacturing a compound semiconductor substrate with a more uniform film thickness (high quality) can be obtained.

  As described above, according to the present invention, the wafer can be freely rotated regardless of whether or not the susceptor is rotated in order to further reduce the variation in the film thickness of the epitaxial wafer as compared with the prior art. It is possible to provide a vapor phase growth apparatus capable of performing vapor phase growth without affecting the rotation of the wafer even if conditions change, and a method of manufacturing a compound semiconductor substrate using the vapor phase growth apparatus.

It is the figure which showed an example of the outline of the vapor phase growth apparatus of this invention. It is the figure explaining the positional relationship in the wafer surface which measured the thickness of the epitaxial film of the epitaxial wafer in Example 1, 2 and the comparative example 1. FIG. It is a figure which shows the measurement result of the thickness of the A direction of the epitaxial film in Example 1, 2 and the comparative example 1. FIG. It is a figure which shows the evaluation result of the ratio of the film thickness of the other location when the thickness of the A direction of the epitaxial film in Example 1, 2 and the comparative example 1 makes the wafer center 1. It is a figure which shows the measurement result of the thickness of the B direction of the epitaxial film in Example 1, 2 and the comparative example 1. FIG. It is a figure which shows the evaluation result of the ratio of the film thickness of another location when the thickness of the epitaxial film in Example 1, 2 and the comparative example 1 makes the wafer center 1. It is a figure which shows the relationship between the rotation number / revolution number of the wafer in each Example and a comparative example, and the value which subtracted the minimum value from the maximum value of the film thickness ratio of an epitaxial film. It is the figure which showed an example of the outline of the conventional vapor phase growth apparatus.

Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a schematic diagram showing an example of a vapor phase growth apparatus according to the present invention.
The vapor phase growth apparatus 10 of the present invention includes at least a reactor 11, a barrel type susceptor (hereinafter also referred to as a carousel) 12 disposed inside the reactor 11, and a susceptor (carousel) 12 for mounting a wafer W. And a tray (hereinafter also referred to as a planetary) 13 disposed on the surface.
The tray (planetary) 13 rotates on a rotating shaft different from that of the susceptor 12, and the susceptor 12 is rotated by a revolving electric motor 14, and the tray 13 rotates via a planetary gear 16. 15 is rotated.

  The revolving electric motor 14 rotates the susceptor 12 to revolve the wafer W, and the susceptor 12 itself rotates without revolving.

Thus, by separating the motor for rotating the tray for mounting the wafer and the motor for rotating the susceptor, the wafer can be rotated independently of the susceptor. In addition, since the tray on which the wafer is mounted is rotated by an electric motor, the wafer can be rotated without being affected by changes in the vapor phase growth conditions in the reactor, and the direction of rotation of the wafer is arbitrary. Since it can be controlled, the controllability of the wafer's self-revolution is high and the degree of freedom during vapor phase growth can be increased, so that the growth conditions can be changed flexibly. Therefore, the vapor phase growth apparatus can make the uniformity of the thickness of the grown vapor phase growth film higher than the conventional one.
Further, since it is a barrel-type susceptor, a vapor phase growth film with few slips, metal contamination, surface defects and the like can be obtained, and this is a vapor phase growth apparatus suitable for improving the production yield.

Here, as shown in FIG. 1, the revolution electric motor 14 and the rotation electric motor 15 may be divided into two axes, with the centers of the rotation axes (14 a, 15 a) not matching each other. it can.
Thus, the axis center of the rotation shaft by the revolution electric motor (revolution rotation shaft axis center 14a) and the axis center of the rotation shaft by the rotation electric motor (rotation rotation shaft axis center 15a) do not coincide with each other. If it is divided into shafts, it is not necessary to make the diameter of the rotating shaft for either wafer revolution or rotation to be thicker than the other rotating shaft, so dead space may occur. In addition, since it is difficult to exhaust the reactor in the reactor, the operation efficiency can be increased. Further, a general rod or the like is sufficient as the rotating shaft, and it can be made inexpensive.

  Although an example of the manufacturing method of the compound semiconductor substrate of this invention using the vapor phase growth apparatus of this invention as mentioned above is shown below, this invention is not limited to these.

First, as shown in FIG. 1, vapor phase growth in which a tray for mounting a wafer can be rotated by a motor (rotational electric motor) different from a revolving electric motor for rotating a susceptor. The wafer is mounted on a tray placed on the susceptor of the apparatus.
The wafer used at this time is not particularly limited as long as a wafer made of a standard material suitable for the compound semiconductor substrate to be manufactured is appropriately selected. For example, when a GaAsP epitaxial wafer is manufactured as a compound semiconductor substrate, an n-type GaP substrate can be used as the wafer.

Then, after the inside of the reactor is replaced with nitrogen gas, a raw material gas is flowed, and the wafer is rotated and revolved while heating the wafer by a heating mechanism (not shown), and a III-V group compound semiconductor is formed on the main surface of the wafer. Vapor growth is performed.
The source gas and vapor phase growth conditions used at this time are not particularly limited, and can be appropriately changed according to the application of the compound semiconductor substrate to be manufactured.

For example, when manufacturing a GaAsP epitaxial wafer, first, nitrogen (N ₂ ) gas is introduced into the reactor, air is sufficiently replaced and removed, high purity hydrogen (H ₂ ) is introduced as a carrier gas, and N ₂ Stop the flow and enter the heating process.
After confirming that the temperatures of the Ga-containing quartz boat installation part and the GaP substrate installation part are kept constant at a predetermined temperature, vapor phase growth of a GaP epitaxial film having the same composition as the GaP substrate is started.

First, an n-type carrier doping gas is introduced into the reactor, high purity hydrogen chloride gas (HCl) is blown into the Ga reservoir in the quartz boat, and GaCl _x is blown out from the upper surface of the Ga reservoir while high purity phosphation is performed. While introducing hydrogen gas (PH ₃ ), a substrate buffer layer as a first layer is grown on the GaP substrate.

Next, the introduction amount of the high purity hydrogen arsenide gas (AsH ₃ ) is started without changing the introduction amount of HCl, and then the introduction amount is gradually increased. At the same time, the introduction amount of the n-type carrier doping gas and PH ₃ is increased. The n-type GaAs _1-x P _x composition change layer to be the second layer is grown on the substrate buffer layer.

Next, the n-type GaAs _1-x P _x composition to be the third layer is kept constant by gradually reducing the introduction amount of the n-type carrier doping gas without changing the introduction amounts of HCl, PH ₃ , and AsH _3. A layer is grown on the GaAs _1-x P _x composition change layer.

Next, without changing the introduction amount of HCl, PH ₃ , AsH ₃ , the nitrogen doping gas is introduced into this, and at the same time, the introduction of the n-type carrier doping gas is stopped, and then the n-type which becomes the fourth layer The nitrogen concentration increasing layer is grown on the GaAs _1-x P _x composition constant layer.

Next, an n-type nitrogen concentration constant layer to be the fifth layer is grown on the nitrogen concentration increasing layer without changing the introduction amounts of HCl, PH ₃ , AsH ₃ , and nitrogen doping gas.

Then, the GaAs _1-x P _x p serving as the sixth layer is increased while increasing the introduction amount of the p-type carrier doping gas without changing the introduction amount of HCl, PH ₃ , AsH ₃ , and nitrogen doping gas. A type carrier concentration increasing layer is grown on the nitrogen concentration constant layer.

Thereafter, the p-type GaAs _{1 serving as} the seventh layer is formed without changing the introduction amount of the HCl, PH ₃ , AsH ₃ , and p-type carrier doping gas, and while gradually reducing the introduction amount of the nitrogen doping gas. the _-x P _x epitaxial layer is grown on the p-type carrier concentration increases layer, it is possible to obtain a GaAsP epitaxial wafer by ending vapor deposition.

Here, in the vapor phase growth, the ratio of the number of rotations of the tray (rotation number) rotated by the electric motor for rotation and the number of rotations (revolution number) of the susceptor rotated by the electric motor for rotation (rotation number / The number of revolutions) can be 4-20.
If the ratio of the number of revolutions and the number of rotations of the wafer is 4 or more, the number of rotations of the wafer can be reduced and the effect of rotation can be prevented from being reduced. Therefore, the film thickness of the compound semiconductor can be made more uniform. . If the ratio is 20 or less, the mechanism for rotating the wafer (electric motor for rotation, planetary gear, etc.) can be prevented from being worn out and generate dust, and a compound semiconductor substrate with few defects can be vapor-phase grown. be able to.

Further, the ratio of the number of rotations of the tray (the number of rotations of the wafer) and the number of rotations of the susceptor (the number of revolutions of the wafer) can be a decimal number instead of an integer.
Thus, if the ratio is set to a decimal number instead of an integer, the number of rotations and revolutions of the wafer can be prevented from being synchronized, and a specific film thickness can be generated in a compound semiconductor that has been vapor-phase grown in advance. Can be prevented. Therefore, a high-quality compound semiconductor substrate with higher film thickness uniformity can be manufactured.

  As described above, according to the method for manufacturing a compound semiconductor substrate of the present invention, a compound semiconductor substrate having a uniform thickness of the epitaxial film on the substrate can be manufactured as compared with the conventional method. A substrate having a vapor phase growth film that can contribute to an increase in yield can be obtained.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
Example 1
The vapor phase growth of the GaP epitaxial film was performed on the main surface of the GaP single crystal substrate using the vapor phase growth apparatus as shown in FIG.
Specifically, first, a GaP single crystal substrate prepared as a wafer was set on a planetary (tray).

Then, nitrogen (N ₂ ) gas is introduced into the reactor for 20 minutes, and after sufficiently replacing and removing the air, high purity hydrogen (H ₂ ) is introduced as a carrier gas, and the introduction of N ₂ gas is stopped and the temperature is increased. Entered warm process.
Thereafter, high purity hydrogen phosphide gas (PH ₃ ) was introduced as a Group V element component of the periodic table.
Further, after reaching a predetermined temperature, high purity hydrogen chloride gas (HCl) is blown into the Ga reservoir in the quartz boat to generate GaCl _x as a Group III element component raw material of the periodic table, and the composition of the single crystal substrate is the same. Vapor phase growth of the GaP epitaxial film was performed. At this time, the rotation speed of the carousel (susceptor) was set to 3 rpm, the rotation speed of the planetary was set to 3 rpm, and vapor phase growth was performed while rotating the GaP single crystal substrate.
When the predetermined film thickness was reached, the introduction of HCl gas, PH ₃ gas, and H ₂ gas was stopped and the vapor phase growth was terminated.

After completion of the vapor phase growth, the epitaxial wafer manufactured from the reactor was taken out, and the thicknesses of the epitaxial films in the A direction and the B direction as shown in FIG. 2 were measured. The measurement results are shown in FIG. 3 for the A direction and in FIG. 5 for the B direction.
Further, in each of the A direction and the B direction, the ratio of the film thicknesses at other locations when the thickness of the epitaxial film at the wafer center was set to 1 was evaluated. The evaluation results are shown in FIG. 4 for the A direction and in FIG. 6 for the B direction.

(Example 2)
In Example 1, vapor phase growth of the epitaxial film was performed under the same conditions except that the rotation speed of the planetary was 30 rpm, and the same evaluation as in Example 1 was performed. The results are shown in Fig. 3-6.

(Comparative Example 1)
In Example 1, vapor phase growth of the epitaxial film was performed under the same conditions except that a dummy rod was set between the electric motor for revolution and the planetary gear so that the rotation speed of the planetary was 0 rpm, Evaluation similar to Example 1 was performed. The results are shown in Fig. 3-6.
In the case of Comparative Example 1 in which the GaP single crystal substrate did not rotate, the A direction was a direction parallel to the axis center of the revolution axis, and the B direction was a tangential direction of the circumference of the revolution.

As shown in FIG. 3, Example 1 has a film thickness in the wafer plane of 52 to 64 μm (maximum difference 12 μm), and Example 2 has 56 to 61 μm (maximum difference 5 μm) and 55 to 74 μm (maximum difference 19 μm). It was found that the variation in film thickness was smaller than that of Comparative Example 1.
Further, as shown in FIG. 4, in Examples 1 and 2, compared with Comparative Example 1 in which the GaP single crystal substrate was not rotated, the film thickness in the wafer surface, particularly the wafer outer peripheral portion, was thicker than the center. It was found that an epitaxial wafer having a uniform film thickness can be obtained. In particular, in Example 2 where the ratio of the number of rotations / revolutions is as large as 10, the ratio of the center of the wafer to the thickness of the epitaxial film is 1 to 1.1, and the ratio of the number of rotations / revolutions is 1 It was found that the in-plane film thickness uniformity was excellent as compared with 1-1.2.

As shown in FIG. 5, also in the B direction, Example 1 has a wafer surface thickness of 52 to 70 μm (maximum difference 18 μm), and Example 2 has a thickness of 56 to 64 μm (maximum difference 8 μm). It was found that the variation in film thickness was small compared to Comparative Example 1 (56 to 85 μm (maximum difference 29 μm)) in which epitaxial growth was performed without rotating the crystal substrate.
In addition, as shown in FIG. 6, in the B direction as well as in the A direction, both the first and second embodiments have a uniform wafer surface compared to the first comparative example, and can particularly improve the film thickness at the outer peripheral portion of the wafer. I understood. And it turned out that the film thickness is more uniform in Example 2 where the ratio of the number of revolutions / revolutions is larger than that in Example 1, and the ratio of the number of revolutions / revolutions is better.

(Example 3)
In Example 1, vapor phase growth of the epitaxial film was performed under the same conditions except that the rotation speed of the planetary was 12 rpm (autorotation number / revolution number = 4), and the same evaluation as in Example 1 was performed.

In each of the examples and comparative examples, when the thickness of the epitaxial film at the center of the wafer is set to 1, the minimum value is subtracted from the maximum value of the film thickness ratio of the epitaxial film to evaluate the film thickness error. went. The relationship between the result and the number of rotations / revolutions of the wafer was evaluated. The result is shown in FIG.
As shown in FIG. 7, it was found that the film thickness became uniform as the ratio of the number of rotations / revolutions was increased.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

DESCRIPTION OF SYMBOLS 10 ... Vapor phase growth apparatus, 11 ... Reactor, 12 ... Susceptor (carousel), 13 ... Tray (planetary), 14 ... Electric motor for revolution, 14a ... Center of rotating shaft for revolution, 15 ... Electric motor for rotation, 15a ... rotation shaft center for rotation, 16 ... planetary gear,
DESCRIPTION OF SYMBOLS 30 ... Vapor growth apparatus, 31 ... Reactor, 32 ... Susceptor, 33 ... Tray, 34 ... Motor for revolution, 35 ... Gas drive rotor for rotation,
W ... wah.

Claims (5)

In a vapor phase growth apparatus comprising at least a reactor, a barrel-type susceptor disposed inside the reactor, and a tray disposed on the surface of the susceptor for mounting a wafer,
Vapor phase growth characterized in that the tray is rotated by a rotating shaft different from that of the susceptor, the susceptor is rotated by an electric motor for revolution, and the tray is rotated by an electric motor for rotation. apparatus.   2. The vapor phase growth apparatus according to claim 1, wherein the revolution electric motor and the rotation electric motor have two rotation axes that do not coincide with each other.   A method of manufacturing a compound semiconductor substrate, comprising: mounting a wafer on the tray disposed on the susceptor using the vapor phase growth apparatus according to claim 1 or 2; and rotating and revolving the wafer. A method for producing a compound semiconductor substrate, comprising vapor-phase-growing a group III-V compound semiconductor on the main surface of the wafer.   The ratio (rotation number / revolution number) of the rotation number (revolution number) of the tray rotated by the rotation electric motor and the rotation number (revolution number) of the susceptor rotated by the revolution electric motor is 4 to 4. The method of manufacturing a compound semiconductor substrate according to claim 3, wherein   The method of manufacturing a compound semiconductor substrate according to claim 4, wherein the ratio is not an integer but a decimal.

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