JP2008243948A - Manufacturing method of epitaxial substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an epitaxial substrate, capable of suppressing decoloration in the rear surface. <P>SOLUTION: This manufacturing method of an epitaxial substrate is provided with a substrate-preparing step, as a step of preparing a GaN substrate, a substrate-disposing step and a film-depositing step. In the substrate disposing step, the GaN substrate 10 is disposed on a susceptor 4, having a surface layer containing silicon carbide (SiC) via an intermediate member 12 made of a material different from the silicon carbide. In the film-depositing step, an epitaxial film is grown on the surface of the GaN substrate 10, by supplying a reaction gas containing ammonium, to a region opposing the surface of the GaN substrate 10 disposed on the susceptor 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an epitaxial substrate manufacturing method, and more particularly to an epitaxial substrate manufacturing method using a GaN substrate as a base.

Conventionally, as a method of manufacturing an epitaxial substrate in which an epitaxial film is formed on a base surface of a GaN substrate or the like, a GaN substrate as a base is placed on a susceptor placed inside a reaction vessel, the GaN substrate is heated and the GaN substrate is heated. There is known a method of forming an epitaxial film on the surface of a GaN substrate by supplying a reactive gas to a region facing the substrate. As a susceptor used when forming the above-described epitaxial film, a susceptor in which the surface of a graphite substrate is coated with silicon carbide (SiC) is known (for example, see Patent Document 1). A susceptor whose surface is coated with SiC (SiC-coated graphite susceptor) is relatively easy to increase in size compared to other materials (for example, a susceptor made of quartz) and can cope with an increase in the size of a GaN substrate. It is considered possible.
JP 2006-237499 A

  When a GaN substrate is mounted on the SiC-coated graphite susceptor described above and an epitaxial film is formed on the GaN substrate with the GaN substrate heated to a temperature of 1000 ° C. or higher, the back surface of the GaN substrate (in contact with the SiC-coated graphite susceptor) The inventor discovered a phenomenon that the main surface) turned black. Such discoloration is considered to be caused by the decomposition of GaN and the precipitation of Ga on the back surface of the GaN substrate. When such discoloration occurs, the contact state between the GaN substrate and the susceptor changes in the film forming process, and as a result, the temperature distribution of the GaN substrate changes. As a result, in-plane PL measurement result variation (that is, local characteristic variation in the formed epitaxial film) occurred in the formed epitaxial film.

  Further, the discoloration of the back surface of the GaN substrate could not be completely wiped off after the film forming process described above. For this reason, there may be a problem that alignment of the mask for exposure becomes difficult when photolithography is applied to the epitaxial substrate after the film forming process. Furthermore, as described above, GaN decomposes on the back surface of the GaN substrate, so that the flatness on the back surface of the GaN substrate deteriorates, and the epitaxial substrate breaks in the process of forming elements after the film forming process (device forming process). There is also a risk that the probability of problems will increase.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to suppress the occurrence of discoloration on the back surface of an epitaxial substrate having an epitaxial film formed on the surface of the GaN substrate. An object of the present invention is to provide a method of manufacturing an epitaxial substrate that can be used.

  As a result of intensive studies on the above-described phenomenon, the inventor has found that the phenomenon of discoloration of the back surface of the GaN substrate is caused by the fact that the back surface of the GaN substrate is in contact with SiC. The inventor presumed that a phenomenon such as decomposition of GaN occurred during the growth of the epitaxial layer due to the back surface of the GaN substrate being in contact with SiC. Thus, as a result of examining the above-described phenomenon, the inventor has found a method in which an intermediate member made of a material different from SiC is disposed between the GaN substrate and the susceptor in order to prevent discoloration of the GaN substrate. That is, the method for manufacturing an epitaxial substrate according to the present invention includes a step of preparing a GaN substrate, a placement step, and a film formation step. In the arranging step, the GaN substrate is arranged on an susceptor having a surface layer containing silicon carbide (SiC) through an intermediate member made of a material different from silicon carbide. In the film forming step, an epitaxial film is grown on the surface of the GaN substrate by supplying a reaction gas containing ammonia to a region facing the surface of the GaN substrate disposed on the susceptor. Here, the epitaxial substrate means a substrate in which an epitaxial film is formed on a base substrate such as a GaN substrate.

  In this way, it is possible to prevent the back surface of the GaN substrate (the main surface facing the susceptor) from directly contacting the surface layer of the susceptor containing SiC in the film forming step of forming an epitaxial film on the GaN substrate. The decomposition of GaN on the back surface of the GaN substrate can be suppressed. As a result, it is possible to prevent discoloration due to the decomposition of GaN on the back surface of the GaN substrate in the film forming process. For this reason, it is possible to suppress the deterioration of the uniformity of the film forming conditions due to the variation in the temperature distribution of the GaN substrate in the film forming process due to the discoloration. As a result, it is possible to suppress deterioration in film quality uniformity of the formed epitaxial film.

  In the epitaxial substrate manufacturing method, the material constituting the intermediate member is quartz, sapphire, graphite, pyrolytic graphite, pyrolytic boron nitride (PBN), a composite of boron nitride (BN) and aluminum nitride (AlN). , And at least one selected from the group consisting of a composite material of boron nitride (BN) and silicon nitride (SiN). In this case, since the intermediate member is made of a material having resistance to the atmosphere in the film formation process of the epitaxial film, the deterioration of the intermediate member in the film formation process of the epitaxial film on the GaN substrate is suppressed, and the back surface of the GaN substrate Can be reliably suppressed.

  In the epitaxial substrate manufacturing method, in the film forming step, an intermediate member may be disposed so as to cover a surface of the GaN substrate facing the intermediate member. In this case, the possibility that the GaN substrate contacts the surface layer of the susceptor containing SiC can be reduced as much as possible by covering the back surface of the GaN substrate with the intermediate member. Therefore, discoloration of the back surface of the GaN substrate can be more reliably suppressed.

  In the method for manufacturing the epitaxial substrate, the intermediate member may have a plate shape. In this case, since the handling of the intermediate member is facilitated, the workability of the process of disposing the GaN substrate on the susceptor via the intermediate member can be improved. In addition, the intermediate member can be manufactured more easily than when the intermediate member has a complicated shape.

  In the method for manufacturing the epitaxial substrate, the thickness of the intermediate member may be not less than 0.01 mm and not more than 1 mm. Here, the GaN substrate may be heated to a predetermined processing temperature via a susceptor in the film forming process. However, if the thickness of the intermediate member is too thick, the heating efficiency of the GaN substrate decreases. In other words, when the same amount of heat as before is output from a heating member such as a heater, if the thickness of the intermediate member is too thick, the time for raising the temperature of the GaN substrate to a predetermined temperature becomes longer or even reaches a predetermined temperature. There may be a case where the temperature of the GaN substrate cannot be raised. Therefore, if the upper limit of the thickness of the intermediate member is 1 mm as described above, the occurrence of such a problem can be avoided. On the other hand, when the thickness of the intermediate member is too thin, there is a high possibility that the intermediate member is damaged during the handling of the intermediate member. Therefore, if the lower limit of the thickness of the intermediate member is set to 0.01 mm as described above, the possibility of such damage to the intermediate member can be reduced to a level that is not practically problematic.

  The thickness of the intermediate member described above is preferably 0.02 mm or more and 0.5 mm or less, and more preferably 0.07 mm or more and 0.2 mm or less.

  According to the present invention, since the back surface of the GaN substrate can be prevented from coming into direct contact with the surface layer of the susceptor containing SiC, decomposition of GaN on the back surface of the GaN substrate can be suppressed. As a result, the occurrence of discoloration on the back surface of the GaN substrate in the film forming process can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

  FIG. 1 is a flowchart for explaining a method of manufacturing an epitaxial substrate according to the present invention. FIG. 2 is a schematic diagram for explaining a film forming process in the method of manufacturing the epitaxial substrate shown in FIG. With reference to FIG. 1 and FIG. 2, the manufacturing method of the epitaxial substrate according to this invention is demonstrated.

  Referring to FIG. 1, in the epitaxial substrate manufacturing method according to the present invention, first, a substrate preparation step (S10) is performed. In this substrate preparation step (S10), a GaN substrate is prepared.

  Next, a substrate placement step (S20) is performed. In the substrate arranging step (S20), the GaN substrate 10 is arranged on the susceptor 4 in the epitaxial growth apparatus (film forming apparatus) as the processing apparatus shown in FIG. At this time, the GaN substrate 10 is disposed on the susceptor 4 via the intermediate member 12. Specifically, a recess 14 is formed on the surface of the susceptor 4, and the intermediate member 12 is disposed on the bottom wall of the recess 14. The intermediate member 12 has a plate shape, and the planar shape thereof is similar to the planar shape of the GaN substrate 10. Alternatively, the planar shape of the intermediate member 12 may be the same as the planar shape of the bottom wall of the recess 14. The intermediate member 12 is made of a material different from SiC. As a material of the intermediate member 12, for example, quartz, sapphire, or the like can be used. In the recess 14, the GaN substrate 10 is disposed on the intermediate member 12.

  The susceptor 4 includes a graphite base material and an SiC layer coated on the surface of the graphite base material. The planar shape of the recess 14 can be any shape as long as the GaN substrate 10 can be disposed inside, but more preferably has a similar shape to the planar shape of the GaN substrate 10. The bottom wall of the recess 14 is flat.

  The configuration of the processing apparatus shown in FIG. 2 will be briefly described. The processing apparatus 1 shown in FIG. 2 has a reaction tube 2 and a GaN substrate 10 disposed at a position facing the inside of the reaction tube 2. A susceptor 4 capable of heating, a heater 8 for heating the GaN substrate 10 via the susceptor 4, a gas supply member 16 for supplying a reaction gas to the inside of the reaction tube 2, and a post-treatment from the inside of the reaction tube 2. It comprises an exhaust member 18 for exhausting reaction gas and the like. The reaction tube 2 is made of a transparent member such as quartz. The cross-sectional shape of the reaction tube 2 in the direction perpendicular to the paper surface can be, for example, a rectangular shape. The susceptor 4 is installed so that the upper surface of the susceptor 4 is located on the same plane as the surface of the bottom wall of the susceptor 4.

  The planar shape of the susceptor 4 can be a circular shape, for example. As described above, the recess 14 is formed on the surface of the susceptor 4. In addition, a support shaft 6 serving as a rotation shaft for rotating the susceptor 4 is installed at the center of the back surface of the susceptor 4 opposite to the front surface. The support shaft 6 is connected to a driving member such as a motor (not shown). As the support shaft 6 is rotated by the drive member, the susceptor 4 is rotatable about the central portion to which the support shaft 6 is connected. A heater 8, which is a heating member for heating the GaN substrate 10 via the susceptor 4, is disposed on the back surface side of the susceptor 4. As the heater 8, any heating device such as a resistance heating element can be used. The gas supply member 16 for supplying the reaction gas to the reaction tube 2 includes a tank that accumulates the reaction gas, a pipe that leads the reaction gas from the tank, and a pipe that is installed in the pipe. And a control valve for controlling ON / OFF of the flow of the reaction gas. Further, the exhaust member 18 includes a pipe connected to the reaction tube 2 and a pump connected to the pipe for discharging gas from the inside of the reaction tube 2. With such a configuration, the reaction gas can flow in the direction indicated by the arrows 21 and 22 inside the reaction tube 2.

  The reaction tube 2 is connected to a pressure measuring member (not shown) for measuring the internal pressure. The pressure inside the reaction tube 2 can be controlled by controlling the gas supply member 16 and the exhaust member 18 based on the measurement result from the pressure measurement member. In order to perform the control, a control unit (not shown) is connected to the pressure measurement member, the gas supply member 16 and the exhaust member 18. The connecting portion is also connected to a driving member for rotating the susceptor 4 and the heater 8, and the rotation operation of the susceptor 4 and the heating conditions from the heater 8 can be controlled. In the processing apparatus 1, a predetermined reaction gas is supplied from the gas supply member 16 into the reaction tube 2 as indicated by an arrow 21, and the GaN substrate 10 is heated by the heater 8, whereby the surface of the GaN substrate 10 is epitaxially formed. A film can be formed.

  Next, as shown in FIG. 1, after performing the substrate placement step (S20), the film formation step (S30) is performed. In the film forming step (S30), in the processing apparatus 1 described above, after adjusting the pressure inside the reaction tube 2 to a predetermined pressure, the heater 8 is used to heat the GaN substrate 10 to a predetermined temperature. A reaction gas is supplied from the supply member 16 into the reaction tube 2. As a result, an epitaxial film is formed on the surface of the GaN substrate 10. The composition of the epitaxial film to be formed can be changed by changing the type of reaction gas supplied from the gas supply member 16. At this time, since the intermediate member 12 is disposed on the back surface side of the GaN substrate 10, the back surface of the GaN substrate 10 and the SiC layer on the surface of the susceptor 4 are not in contact with each other. Therefore, since the decomposition of GaN on the back surface of the GaN substrate 10 is suppressed, the occurrence of discoloration on the back surface of the GaN substrate 10 (adherence of foreign matters accompanying the decomposition of GaN) is suppressed.

  Next, a post-processing step (S40) is performed as shown in FIG. Specifically, the supply of the reaction gas from the gas supply member 16 into the reaction tube 2 is stopped, and the heating of the GaN substrate 10 by the heater 8 is stopped. Then, after the temperature of the GaN substrate 10 is lowered to a predetermined temperature, the atmosphere inside the reaction tube 2 is changed to an air atmosphere, and the GaN substrate 10 on which the epitaxial film is formed (that is, the epitaxial substrate) is taken out from the susceptor 4. In this way, an epitaxial substrate can be obtained.

  Although there are portions that partially overlap with the above-described embodiment, if the characteristic configuration of the present invention is summarized, the epitaxial substrate manufacturing method according to the present invention is a substrate preparation step as a step of preparing a GaN substrate. (S10), a substrate placement step (S20), and a film formation step (S30). In the substrate arranging step (S20), as shown in FIG. 2, the GaN substrate 10 is placed on the susceptor 4 having a surface layer containing silicon carbide (SiC) via an intermediate member 12 made of a material different from silicon carbide. Deploy. In the film forming step (30), an epitaxial film is grown on the surface of the GaN substrate 10 by supplying a reactive gas containing ammonia to a region facing the surface of the GaN substrate 10 disposed on the susceptor 4.

  In this way, it is possible to prevent the back surface of the GaN substrate 10 from directly contacting the surface layer of the susceptor 4 containing SiC in the film forming step (S30) for forming an epitaxial film on the GaN substrate 10. For this reason, decomposition of GaN on the back surface of the GaN substrate 10 can be suppressed. As a result, it is possible to prevent discoloration due to the decomposition of GaN on the back surface of the GaN substrate 10 in the film forming step (S30). Therefore, it is possible to suppress the deterioration of the uniformity of the film forming conditions due to the temperature distribution of the GaN substrate 10 in the film forming step (S30) being varied due to the discoloration. As a result, it is possible to suppress deterioration in film quality uniformity of the formed epitaxial film.

In the epitaxial substrate manufacturing method, the material constituting the intermediate member 12 is quartz, sapphire, graphite, pyrolytic graphite, pyrolytic boron nitride (PBN), a composite of boron nitride (BN) and aluminum nitride (AlN). And at least one selected from the group consisting of a material and a composite material of boron nitride (BN) and silicon nitride (SiN). As a composite material of BN and AlN, for example, a composite material containing 40% by mass of BN and 60% by mass of AlN can be used. As the composite material of BN and SiN, for example, a composite material containing 70% by mass of Si ₃ N ₄ and 30% by mass of BN can be used. Further, as a composite material of BN and SiN, a composite material having a mass ratio of Si ₃ N ₄ : BN = 5: 5 or Si ₃ N ₄ : BN = 3: 7 may be used. In this case, since the material having resistance to the atmospheric gas in the film forming process is used as the constituent material of the intermediate member 12, the deterioration of the intermediate member 12 and the like in the film forming process (S30) are suppressed and the discoloration of the back surface of the GaN substrate 10 is performed. Can be reliably suppressed. In addition, it is preferable that the surface which contacts the GaN substrate of the intermediate member 12 is comprised with the material mentioned above, for example, the shape of the intermediate member 12 is formed as a base member with a material different from the material mentioned above, The said base member You may coat | cover the surface of this with the coating layer which consists of materials, such as the above-mentioned pyrolytic graphite.

  In the epitaxial substrate manufacturing method, in the film forming step (S30), as shown in FIG. 2, the intermediate member 12 is disposed so as to cover the front surface (back surface) of the GaN substrate 10 facing the intermediate member 12. In this case, by covering the back surface of the GaN substrate 10 with the intermediate member 12, it is possible to reliably prevent the GaN substrate 10 from coming into contact with the surface layer (SiC coating surface) of the susceptor containing SiC. Therefore, discoloration of the back surface of the GaN substrate 10 can be more reliably suppressed.

  In the epitaxial substrate manufacturing method, the intermediate member 12 has a plate shape. In this case, since the handling of the intermediate member 12 becomes easy, the workability of the process of arranging the GaN substrate 10 on the susceptor 4 via the intermediate member 12 can be improved. In addition, the intermediate member 12 can be manufactured more easily than when the intermediate member 12 has a complicated shape with irregularities on the surface.

  In the epitaxial substrate manufacturing method, the thickness of the intermediate member 12 is set to 0.01 mm or more and 1 mm or less. The thickness of the intermediate member 12 can be preferably 0.02 mm to 0.5 mm, more preferably 0.07 mm to 0.2 mm.

  In the epitaxial substrate manufacturing method, as shown in FIG. 2, the susceptor 4 is formed with a recess 14 for placing the intermediate member 12 and the GaN substrate 10 therein. Inside the recess 14, the intermediate member 12 and the GaN substrate 10 are stacked from the bottom wall side of the recess 14. In this case, by positioning the intermediate member 12 and the GaN substrate 10 in order inside the recess 14, the intermediate member 12 and the GaN substrate 10 can be easily positioned on the susceptor 4. Further, the depth of the recess 14 may be substantially the same as the total thickness of the GaN substrate 10 and the intermediate member 12.

The susceptor 4 shown in FIG. 2 is configured to hold the GaN substrate 10 in a face-up state, but the present invention may hold the GaN substrate 10 in a face-down state. Also in this case, by arranging the intermediate member 12 between the surface (lower surface) of the susceptor 4 and the GaN substrate 10, the above-described effects of the present invention can be obtained.
(Example)
In order to confirm the effect of the present invention, the following experiment was conducted. That is, a blue light emitting diode structure was formed by metal organic chemical vapor deposition (MOCVD) using a GaN substrate. At this time, the epitaxial substrate manufacturing method according to the present invention was used for the sample of the example, and the conventional epitaxial substrate manufacturing method was used for the sample of the comparative example. The contents of the experiment will be described below.
(sample)
Three GaN (0001) substrates were prepared. Among them, two GaN substrates were used as samples of Examples 1 and 2 of the present invention, and the remaining one GaN substrate was used as a sample for comparison. As for the size of the substrate, the planar shape is substantially circular, the diameter is 50 mm, and the thickness is 0.35 mm.
(Experimental device)
As an experimental apparatus, a vapor phase growth apparatus for carrying out a metal organic chemical vapor deposition method for forming an epitaxial film was prepared. The basic structure of the vapor phase growth apparatus is the same as that of the processing apparatus shown in FIG. As the susceptor, an SiC-coated graphite susceptor made of graphite having a surface coated with SiC was used. However, the susceptor used when processing the samples of Examples 1 and 2 was formed with a recess having a depth of 0.43 mm on the surface thereof as shown in FIG. A quartz plate having a thickness of 0.2 μm was disposed inside the substrate, and a sapphire plate having a thickness of 0.2 μm was disposed as an intermediate member inside the recess when the sample of Example 2 was processed. Further, the susceptor used when processing the sample of the comparative example has a recess having a depth substantially the same as the thickness of the GaN substrate.
(Processing method)
For Example 1:
In the recess of the susceptor, a GaN substrate was placed on the quartz plate. The back surface of the GaN substrate facing the quartz plate was an N surface. Next, while controlling the pressure inside the reaction tube to 100 kPa, NH ₃ gas and H ₂ gas were introduced into the reaction tube. The temperature of the GaN substrate was set to 1050 ° C. by heating with a heater. The cleaning process was carried out by holding in this state for 10 minutes.

Thereafter, while maintaining the temperature of the GaN substrate at 1050 ° C. and the pressure inside the reaction tube at 100 kPa, trimethylgallium, trimethylaluminum, ammonia, and silane were introduced as reaction gases from the gas supply member into the reaction tube. In this way, an n-type Al _0.12 GaN intermediate layer having a thickness of 50 nm was grown on the surface of the GaN substrate.

  Thereafter, while maintaining the temperature of the GaN substrate at 1050 ° C. and the pressure inside the reaction tube at 100 kPa, an n-type GaN buffer layer was further grown to a thickness of 2000 nm. The growth rate of the n-type GaN buffer layer was about 4 μm / hour (h).

  Next, the temperature of the GaN substrate was set to 800 ° C. And the light emitting layer which consists of a multiple quantum well structure was formed by controlling the composition of the reaction gas supplied to the inside of a reaction tube. As the light emitting layer, a laminated structure was formed in which six pairs (six periods) of an InGaN barrier layer having a thickness of 15 nm and an InGaN quantum well layer having a thickness of 3 nm were alternately laminated.

Next, the temperature of the GaN substrate was raised to 1000 ° C. again by the heater 8. Thereafter, trimethylaluminum, trimethylindium, ammonia, and cyclopentadienylmagnesium as reaction gases were introduced into the reaction tube 2 to form an Mg-doped Al _0.12 GaN electron block layer on the light emitting layer. The thickness of the electron blocking layer was 20 nm. Thereafter, trimethylindium, ammonia, and biscyclopentadienylmagnesium were introduced into the reaction tube 2 to form a p-type GaN layer on the electron blocking layer. The thickness of the p-type GaN layer was 50 nm. In this way, an epitaxial substrate as Example 1 of the present invention was produced.

For Example 2:
In the recess of the susceptor, a GaN substrate was placed on the sapphire plate. The back surface of the GaN substrate facing the sapphire plate was an N surface. Thereafter, an epitaxial substrate as Example 2 of the present invention was produced by performing the same process as in Example 1 described above.

About the comparative example:
In the recess of the susceptor, the GaN substrate was disposed so that the surface of the SiC-coated graphite susceptor and the back surface of the GaN substrate were in direct contact. The back surface of the GaN substrate was an N surface. Thereafter, an epitaxial substrate as a comparative example of the present invention was prepared by performing the same process as in Example 1 described above.
(Evaluation contents and results)
For Example 1:
The epitaxial substrate as Example 1 formed as described above was taken out of the reaction chamber, and the appearance was confirmed. As a result, no abnormality such as discoloration was observed on the back surface of the epitaxial substrate of Example 1. Further, when the PL wavelength distribution of the epitaxial substrate was measured using a PL mapping measuring apparatus, the center wavelength was 470 nm and the standard deviation (σ) was 2 nm.

For Example 2:
The epitaxial substrate as Example 2 formed as described above was taken out of the reaction chamber, and the appearance was confirmed. As a result, like the epitaxial substrate of Example 1, no abnormality such as discoloration was observed on the back surface of the epitaxial substrate of Example 2. Further, when the PL wavelength distribution of the epitaxial substrate was measured using the PL mapping measuring apparatus in the same manner as the epitaxial substrate of Example 1, the center wavelength was 472 nm and the standard deviation (σ) was 2.3 nm.

About the comparative example:
The epitaxial substrate as a comparative example formed as described above was taken out of the reaction chamber and the appearance was confirmed. As a result, a black discoloration portion was visually confirmed on the back surface of the epitaxial substrate. Similarly to the epitaxial substrate of Example 1, when the PL wavelength distribution of the epitaxial substrate was measured using a PL mapper device, the center wavelength was 460 nm and the standard deviation (σ) was 7 nm.

  Thus, it can be seen that in the epitaxial substrates of Examples 1 and 2 of the present invention, the occurrence of discoloration on the back surface of the substrate can be suppressed, and the variation in the PL wavelength distribution is reduced.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is advantageously applied to a method for manufacturing an epitaxial substrate in which an epitaxial film is formed on a GaN substrate, particularly used for a light emitting device.

It is a flowchart for demonstrating the manufacturing method of the epitaxial substrate according to this invention. It is a schematic diagram for demonstrating the film-forming process in the manufacturing method of the epitaxial substrate shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Processing apparatus, 2 reaction tube, 4 susceptor, 6 spindle, 8 heater, 10 board | substrate, 12 intermediate member, 14 recessed part, 16 gas supply member, 18 exhaust member, 21,22 arrow.

Claims (5)

Preparing a GaN substrate;
An arrangement step of arranging the GaN substrate on a susceptor having a surface layer containing silicon carbide via an intermediate member made of a material different from silicon carbide;
A deposition step of growing an epitaxial film on the surface of the GaN substrate by supplying a reaction gas containing ammonia to a region facing the surface of the GaN substrate disposed on the susceptor. Production method.   The material constituting the intermediate member is selected from the group consisting of quartz, sapphire, graphite, pyrolytic graphite, pyrolytic boron nitride, a composite material of boron nitride and aluminum nitride, and a composite material of boron nitride and silicon nitride. The method for manufacturing an epitaxial substrate according to claim 1, comprising at least one of the following.   3. The method for manufacturing an epitaxial substrate according to claim 1, wherein in the film forming step, the intermediate member is disposed so as to cover a surface of the GaN substrate facing the intermediate member.   The method for manufacturing an epitaxial substrate according to claim 1, wherein the intermediate member has a plate shape.   The manufacturing method of the epitaxial substrate of any one of Claims 1-4 whose thickness of the said intermediate member is 0.01 mm or more and 1 mm or less.

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