JP5263900B2 - Method for growing single crystal SiC - Google Patents

Description

  The present invention relates to a method for growing single crystal SiC by epitaxially growing single crystal SiC on a single crystal SiC substrate.

  SiC is superior in heat resistance and mechanical strength, is resistant to radiation, can easily control valence electrons of electrons and holes by adding impurities, and has a wide band gap. Therefore, it is expected as a semiconductor material for next-generation power devices and high-frequency devices.

  However, single crystal SiC is susceptible to crystal defects such as basal plane dislocations, screw dislocations, and micropipes due to the effects of heat, and crystal grain boundaries due to nucleation are likely to occur. There is a problem that it is difficult to obtain stable single crystal SiC.

  As means for solving these problems, in Patent Documents 1 to 3, a single heat treatment is performed by interposing a Si melt layer having a predetermined thickness between a single crystal SiC substrate and a carbon atom supply substrate. A metastable solvent epitaxial method (MSE method) for epitaxially growing single crystal SiC on a crystalline SiC substrate has been proposed. This MSE method has the advantage that micro-pipe defects are suppressed and single crystal SiC having a high flatness can be realized, and also has the advantage of a high growth rate.

WO2002 / 099169 JP 2005-126248 A JP 2005-126249 A

  However, although the techniques disclosed in Patent Documents 1 to 3 can suppress the occurrence of micropipe defects, they sufficiently suppress the generation of crystal defects such as basal plane dislocations and spiral dislocations other than micropipes. I couldn't say that.

  Therefore, the present invention can sufficiently suppress the generation of not only micropipe defects but also crystal defects such as basal plane dislocations and screw dislocations, and obtain a single crystal SiC epitaxial layer that is stable in terms of performance and quality. It is an object of the present invention to provide a method for growing single crystal SiC that can be produced.

The present inventor has found that a single-crystal SiC epitaxial layer in which generation of crystal defects is sufficiently suppressed can be obtained by adding a new device to the conventional MSE method to solve the above problems. The invention has been completed.
Hereinafter, first to eighth techniques related to the present invention will be described.

The first technique related to the present invention is:
A single crystal SiC is epitaxially grown on the single crystal SiC substrate by performing a heat treatment with a Si melt layer having a predetermined thickness interposed between the single crystal SiC substrate and the carbon atom supply substrate. The growth method of
The single-crystal SiC growth method includes a degassing / dehydration process for removing gas / water in the reaction system, a Si heating process for raising the temperature to a temperature higher than the melting point of Si, and a Si melting process at a temperature higher than the melting point of Si. A Si melting step for forming a liquid, and a SiC growth step for epitaxially growing single crystal SiC on a single crystal SiC substrate at an epitaxial growth temperature,
The Si temperature raising step is a first temperature raising step in which the temperature is raised to a predetermined temperature in the vicinity of the Si melting point that does not exceed the Si melting point at a predetermined heating rate that keeps the in-plane temperature of the single crystal SiC substrate constant. And a second temperature raising step of raising the temperature from a predetermined temperature near the Si melting point not exceeding the Si melting point to a temperature equal to or higher than the Si melting point.

In the first technique , in the Si temperature raising step, the temperature is raised to a predetermined temperature in the vicinity of the Si melting point that does not exceed the Si melting point at a predetermined heating rate that keeps the in-plane temperature of the single crystal SiC substrate constant Since the first temperature raising step is provided, single crystal SiC can be epitaxially grown sufficiently uniformly on the single crystal SiC substrate even in the plane, and generation of crystal defects can be sufficiently suppressed.

  As a result of examining the cause of crystal defects such as basal plane dislocations and screw dislocations in the conventional MSE method, the present inventor has not sufficiently maintained the in-plane temperature of the single crystal SiC substrate. I found out that is the cause.

  As a result of studying means for sufficiently maintaining the in-plane temperature of the single-crystal SiC substrate, the rate of temperature increase is slowed down to a predetermined temperature near the Si melting point that does not exceed the Si melting point compared to the conventional MSE method. When a single crystal SiC substrate is heated at a predetermined rate to keep the in-plane temperature uniform, a single crystal SiC epitaxial layer in which generation of crystal defects such as basal plane dislocations and spiral dislocations is suppressed can be obtained. I understood that.

  In addition, a 2nd temperature rising process is a temperature rising process heated up to the temperature more than Si melting | fusing point after a 1st temperature rising process, and is a process by which Si melt is produced | generated. The temperature increase rate in this step may be determined by appropriately selecting a temperature increase rate capable of generating a Si melt having no temperature variation, and is the same as the temperature increase rate in the first temperature increase step. Alternatively, different heating rates may be used.

The second technique related to the present invention is:
The method for growing single-crystal SiC according to the first technique , wherein a temperature increase rate in the second temperature increase step is faster than a temperature increase rate in the first temperature increase step.

  When the temperature becomes higher than the melting point of Si, Si melts to form a Si melt, but on the other hand, the evaporation of the Si melt also begins. Until the epitaxial growth temperature higher than the Si melting point is reached, the Si melt evaporates without being involved in the growth. Therefore, in order to secure the amount of Si melt necessary for the growth process, the amount of Si evaporation is also reduced. It is necessary to suppress it.

  Therefore, it is preferable that the temperature increase rate in the second temperature increase step is faster than the temperature increase rate in the first temperature increase step, thereby shortening the temperature increase time and suppressing the evaporation of Si. By shortening the heating time, it is possible to reduce the amount of Si evaporated without directly relating to the epitaxial growth of the single crystal SiC on the single crystal SiC substrate, thereby reducing the manufacturing cost. it can.

The third technique related to the present invention is:
After the completion of the SiC growth step, the single crystal SiC growth method according to the first technique or the second technique , wherein an evaporation process for completely evaporating the Si melt is performed.

  If the Si melt remains even after the end of the SiC growth step, the remaining Si solidifies when the temperature is lowered to take out the grown SiC substrate. Since the thermal expansion coefficients of SiC and Si are different, stress may be generated in the SiC substrate during the temperature lowering process, which may cause crystal defects. Therefore, it is preferable to completely evaporate the Si melt. Specifically, it is preferable that the evaporation process is performed after the predetermined SiC growth, which has been determined in advance, is placed at a temperature higher than the Si melting point.

The fourth technique related to the present invention is:
The single crystal SiC growth method according to the third technique , wherein the evaporation process is a process of evaporating the Si melt while maintaining the epitaxial growth temperature.

In the fourth technique , after the SiC growth step is completed, the Si melt is evaporated while maintaining the epitaxial growth temperature. Therefore, the Si melt can be completely evaporated in a short time.

The fifth technique related to the present invention is:
The single crystal SiC growth method according to the third technique , wherein the evaporation process is a process of evaporating a Si melt in a temperature range from the epitaxial growth temperature to the Si melting point.

The fifth technique utilizes the fact that Si evaporates even in the temperature range from the epitaxial growth temperature to the Si melting point. By evaporating the Si melt in the temperature range from the epitaxial growth temperature to the Si melting point, the influence on the productivity can be reduced and the Si melt can be evaporated.

The sixth technique related to the present invention is:
Any one of the first to fifth techniques is characterized in that the single crystal SiC substrate having undergone the evaporation process is subjected to a temperature lowering process for lowering the temperature at a predetermined temperature lowering rate that relaxes the thermal stress of the single crystal SiC substrate. A method for growing single crystal SiC as described above.

  In order to take out the grown SiC substrate, it is necessary to lower the temperature to the take-out temperature. However, when the temperature lowering rate is high, thermal stress is accumulated on the SiC substrate, and crystal defects such as basal plane dislocations and spiral dislocations may occur. Therefore, it is preferable to perform a temperature lowering process for lowering the thermal stress of the single crystal SiC substrate at a predetermined temperature lowering rate to suppress accumulation of thermal stress on the SiC substrate accompanying the temperature decrease.

The seventh technique related to the present invention is:
And the single crystal SiC substrate, a first technique to a buffer layer made of a first single crystal SiC epitaxial layer formed on the single crystal SiC substrate by method of growing single crystal SiC of any crab according to the sixth technical And a single crystal SiC epitaxial substrate comprising an active layer made of a second single crystal SiC epitaxial growth layer formed on the buffer layer.

  According to the study of the present inventors, it has been found that the SiC epitaxial layer generated by the MSE method has a characteristic (defect propagation reduction function) that is difficult to propagate crystal defects such as basal plane dislocations and spiral dislocations. . That is, the buffer layer suppresses the crystal defect generated in the single crystal SiC substrate from propagating to the active layer.

In the seventh technique , the buffer layer formed of the first single crystal SiC epitaxial layer is a buffer layer in which crystal defects are sufficiently suppressed.

  As a result, when an active layer made of the second single crystal SiC epitaxial growth layer is formed on such a buffer layer, a single crystal SiC epitaxial substrate having an active layer with extremely suppressed crystal defects can be provided. . In addition, as a means for forming the second single crystal SiC epitaxial growth layer, a known method such as a vapor phase growth method or a liquid phase growth method can be adopted and is not particularly limited.

The eighth technique related to the present invention is:
A method for producing a single crystal SiC epitaxial substrate according to a seventh technique ,
A first single-crystal SiC epitaxial layer generating step of generating the first technology to the first single-crystal SiC epitaxial layer on a single crystal SiC substrate by method of growing single crystal SiC of any crab according to the sixth technical ,
And a second single crystal SiC epitaxial layer generation step of generating a second single crystal SiC epitaxial layer by vapor deposition on the first single crystal SiC epitaxial layer. It is a manufacturing method.

An eighth technique is a method for manufacturing a single crystal SiC epitaxial substrate described in the seventh technique , in which a second single crystal SiC epitaxial layer is generated by vapor phase growth.

The vapor phase growth method is preferable as a method for generating the second single crystal SiC epitaxial layer because the thickness of the layer can be easily and accurately controlled as compared with other growth methods. Therefore, according to the eighth technique , in addition to the effect of the buffer layer by the MSE method, it is possible to provide a single crystal SiC epitaxial substrate including an active layer whose thickness is accurately and uniformly controlled. A high-quality and high-performance semiconductor device can be provided with a high yield.

  In addition, it does not specifically limit as a specific vapor phase growth method, For example, conventionally well-known methods, such as CVD method, PVD method, MBE method, are employable.

The present invention has been made on the basis of the above-described technologies, and the invention according to claim 1
A single crystal SiC is epitaxially grown on the single crystal SiC substrate by performing a heat treatment with a Si melt layer having a predetermined thickness interposed between the single crystal SiC substrate and the carbon atom supply substrate. The growth method of
The single-crystal SiC growth method includes a degassing / dehydration process for removing gas / water in the reaction system, a Si heating process for raising the temperature to a temperature higher than the melting point of Si, A Si melting step for forming a liquid, and a SiC growth step for epitaxially growing single crystal SiC on a single crystal SiC substrate at an epitaxial growth temperature,
The Si temperature raising step is a first temperature raising step in which the temperature is raised to a predetermined temperature in the vicinity of the Si melting point that does not exceed the Si melting point at a predetermined heating rate that keeps the in-plane temperature of the single crystal SiC substrate constant. And a second temperature raising step for raising the temperature from a predetermined temperature near the Si melting point not exceeding the Si melting point to a temperature equal to or higher than the Si melting point,
After the completion of the SiC growth step, an evaporation process for completely evaporating the Si melt is performed.

The invention according to claim 2
2. The method for growing single crystal SiC according to claim 1, wherein a temperature increase rate in the second temperature increase step is faster than a temperature increase rate in the first temperature increase step.

The invention according to claim 3
3. The single crystal SiC growth method according to claim 1, wherein the evaporation process is a process of evaporating a Si melt while maintaining the epitaxial growth temperature.

The invention according to claim 4
3. The single crystal SiC growth method according to claim 1, wherein the evaporation process is a process of evaporating a Si melt in a temperature range from the epitaxial growth temperature to the Si melting point.

The invention according to claim 5
5. The temperature lowering process for lowering the temperature of the single-crystal SiC substrate after the evaporation process at a predetermined temperature-decreasing rate that relaxes thermal stress of the single-crystal SiC substrate is performed. The method for growing single crystal SiC according to the item.

The invention according to claim 6
A buffer layer comprising a single crystal SiC substrate and a first single crystal SiC epitaxial layer formed on the single crystal SiC substrate by the single crystal SiC growth method according to any one of claims 1 to 5. And a single crystal SiC epitaxial substrate comprising an active layer made of a second single crystal SiC epitaxial growth layer formed on the buffer layer.

The invention according to claim 7
A method for producing a single crystal SiC epitaxial substrate according to claim 6,
A first single crystal SiC epitaxial layer generation step for generating a first single crystal SiC epitaxial layer on a single crystal SiC substrate by the single crystal SiC growth method according to any one of claims 1 to 5. ,
A second single crystal SiC epitaxial layer generating step of generating a second single crystal SiC epitaxial layer on the first single crystal SiC epitaxial layer by vapor deposition;
Is a method for manufacturing a single crystal SiC epitaxial substrate.

  According to the present invention, not only micropipe defects but also crystal defects such as basal plane dislocations and screw dislocations can be sufficiently suppressed to obtain a single crystal SiC epitaxial layer that is stable in terms of performance and quality. It is possible to provide a method for growing single crystal SiC.

  Also, an active layer with extremely few crystal defects can be obtained by forming the single crystal SiC epitaxial layer obtained by the present invention as a buffer layer and forming a second single crystal SiC epitaxial growth layer as an active layer thereon. Therefore, it is possible to provide a high-quality and high-performance semiconductor device with a high yield.

It is the schematic explaining the growth method of the single crystal SiC which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

(Embodiment)
FIG. 1 is a schematic diagram for explaining an embodiment of a method for growing single crystal SiC according to the present invention. In FIG. 1, reference numeral 8 denotes a container (susceptor). The carbon atom supply substrate 3, the Si plate 2, the spacer 4, the single crystal SiC substrate 1, the spacer 4 ′, and the carbon atom supply substrate 3 are placed inside the container 8 from below. 'Is arranged in order, and the weight 6 is arranged at the top.

  A space 5 is provided by sandwiching a spacer 4 between the single crystal SiC substrate 1 and the Si plate 2. In the space 5, the Si melt generated by melting from the Si plate 2 at a temperature equal to or higher than the melting point of Si is held, and single crystal SiC is epitaxially grown on the surface of the single crystal SiC substrate 1.

  Similarly, a space 7 is provided by disposing a spacer 4 ′ between the single crystal SiC substrate 1 and the carbon atom supply substrate 3 ′. The space 7 is provided for the purpose of preventing the Si melt that has entered the back surface side (upper side in the drawing) of the single crystal SiC substrate 1 from coming into contact with the carbon atom supply substrate 3 ′.

  As the single crystal SiC substrate 1, a conventionally known single crystal SiC substrate can be used, and a commercially available single crystal SiC substrate may be used. Single crystal SiC is epitaxially grown on the single crystal SiC substrate. In addition, it is preferable to planarize the surface on the side to be epitaxially grown in advance by a CMP method (chemical mechanical polishing method) to remove polishing marks and the like.

  The Si plate 2 is melted at a temperature equal to or higher than the melting point to generate a Si melt in the space 5.

  Carbon atom supply substrate 3 supplies carbon onto single-crystal SiC substrate 1 via Si plate 2 and Si melt layer (space 5) during heat treatment. The material is not particularly limited as long as carbon can be supplied onto the single crystal SiC substrate 1. For example, a polycrystalline SiC substrate, a carbon substrate, a porous SiC substrate, a sintered SiC substrate, an amorphous SiC substrate, or the like can be used. Can be used. It is preferable that the surface of the carbon atom supply substrate is polished to a mirror surface in advance, and oils, oxide films, metals, and the like attached to the surface are removed by washing or the like.

  The spacer 4 defines the distance between the single crystal SiC substrate 1 and the Si plate 2 and defines the thickness of the Si melt layer and the epitaxially grown single crystal SiC epitaxial layer in the space 5. Thereby, the thickness of the single crystal SiC epitaxial layer can be made uniform over the entire growth surface.

  The configuration of the spacer 4 is not particularly limited as long as the distance between the single crystal SiC substrate 1 and the Si plate 2 can be appropriately defined. For example, the spacer 4 is formed on the single crystal SiC substrate 1 by machining. It may be formed on the single crystal SiC substrate 1 by lithography, vapor deposition, sputtering, ion plating, vapor phase growth, or the like. Further, it may be formed on the Si plate 2 instead of being formed on the single crystal SiC substrate 1. Alternatively, the spacer 4 may be sandwiched between the single crystal SiC substrate 1 and the Si plate 2.

  The cross-sectional shape of the spacer 4 is not particularly limited, and various shapes such as a cylindrical shape and a rectangular parallelepiped shape can be used.

  The thickness of the spacer 4 is not particularly limited as long as the carbon supplied from the carbon atom supply substrate 3 can move to the surface of the single crystal SiC substrate 1, but is 1 for proper movement. ˜50 μm is preferred.

Next, the single crystal SiC growth method in the present embodiment will be described in the order of steps.
(1) Degassing / Dehydrating Step Each member is housed in a container 8 as shown in FIG. 1, and after reducing the pressure to, for example, 10 ⁻⁴ Pa or less to form a vacuum atmosphere, this pressure state is maintained, Degassing / dehydrating is performed by raising the temperature in the container 8 from room temperature to 500 ° C. using a heating means (not shown) and holding the temperature for 30 minutes. As long as degassing / dehydration can be performed appropriately, the conditions of this step are not limited. For example, the temperature may be raised to 200 ° C. and held for 60 minutes. Further, the temperature may be raised from 200 ° C. to 500 ° C. at a rate of 5 ° C./min, and degassing / dehydration may be performed in the process.

(2) First Si temperature raising step Next, in order to sufficiently maintain the soaking of the in-plane temperature of the single crystal SiC substrate 1 up to a predetermined temperature near the Si melting point that does not exceed the Si melting point, for example, 1300 ° C., The temperature is increased at a temperature increase rate of 7.0 to 10.0 ° C./min.

(3) Second Si temperature raising step and Si melting step Next, the temperature is raised to a predetermined growth temperature, for example, 1800 ° C., at a temperature raising rate of 20 to 40 ° C./min so as to suppress the evaporation of Si. Do. The melting point of Si is 1420 ° C., and Si melt is formed in the space 5 from the Si plate 2.

  In this embodiment, since the heat treatment is performed in a vacuum atmosphere, the temperature rise rate is increased so that the evaporation of Si can be suppressed. However, an inert gas such as Ar is introduced to grow the atmospheric pressure. The evaporation may be suppressed using a method of suppressing the evaporation of Si by increasing the height, a container having high airtightness such as carbon or a high melting point metal.

(4) SiC growth step Thereafter, the growth temperature is maintained for a predetermined time, and the Si melt is completely evaporated. During this time, carbon is dissolved from the carbon atom supply substrate 3 into the Si melt formed in the space 5 through the Si plate, and single crystal SiC is epitaxially grown on the single crystal SiC substrate. The epitaxial growth stops when the Si melt is completely evaporated.

(5) Temperature drop step Next, in order to prevent thermal stress from accumulating on the single crystal SiC substrate 1 on which single crystal SiC is epitaxially grown from the growth temperature to a predetermined temperature of 1000 ° C. or lower, for example, 800 ° C., 0.1 to 10 ° C. The temperature is lowered at a rate of temperature reduction per minute.

(6) Extraction step Further, the single crystal SiC substrate 1 on which the single crystal SiC substrate 1 obtained by performing natural cooling and epitaxially growing the single crystal SiC at a temperature of 100 ° C. or less is extracted and the single crystal SiC epitaxial layer according to the present invention is generated is obtained. 1 can be obtained.

(Example)
A single crystal SiC substrate on which a single crystal SiC epitaxial layer was generated was obtained under the specific heat treatment conditions shown below. A 4H—SiC single crystal substrate was used as the single crystal SiC substrate, and a polycrystalline SiC substrate was used as the carbon atom supply substrate 3, and a spacer having a thickness of 50 μm was sandwiched therebetween.

  Next, the temperature is raised from 500 ° C. to 1300 ° C. at a rate of 10 ° C./min, and thereafter, from 1300 ° C. to 1800 ° C. which is the growth temperature, 30.0 ° C. / The temperature was increased at a temperature increase rate of minutes. Next, it was held at a growth temperature (1800 ° C.) for 40 minutes to produce an epitaxial growth layer having a thickness of 7.1 μm. Thereafter, the temperature is lowered at a rate of 1.0 ° C./min so that thermal stress is not accumulated on the single crystal SiC substrate on which single crystal SiC is epitaxially grown from the growth temperature (1800 ° C.) to 800 ° C., and further natural cooling is performed. The single crystal SiC substrate was taken out at 40 ° C. During the temperature drop, no cracks were observed.

  The obtained single crystal SiC epitaxial layer was an epitaxial layer with very few crystal defects.

(Measurement of defect propagation reduction function)
The surface of the single crystal SiC epitaxial layer of the single crystal SiC substrate having the single crystal SiC epitaxial layer of the above example was subjected to molten KOH etching, and etch pit observation was performed. The observation results are shown in Table 1 as the MSE film surface.

  Next, the single crystal SiC epitaxial growth layer was completely removed by a polishing process to expose a single crystal SiC substrate. Thereafter, similarly, molten KOH etching was performed, and etch pit observation was performed. The observation results are shown in Table 1 as the SiC substrate surface.

In Table 1, the result on the SiC substrate surface is the dislocation density (unit: piece / cm ² ) of each defect, and the result on the MSE film surface is the dislocation density (unit: piece / cm ² ) for the basal plane dislocation defect, About a micropipe defect and a screw dislocation defect, it shows by the ratio (unit:%) with respect to the result of the SiC substrate surface.

  From the results in Table 1, it can be seen that the propagation of micropipe defects and spiral dislocation defects to the buffer layer surface in the single crystal SiC substrate can be reduced by 95% or more, and the basal plane dislocations can be further reduced.

  As described above, since the single crystal SiC epitaxial layer according to the present invention has the characteristic of suppressing the propagation of crystal defects, the second single crystal is formed thereon by using the buffer layer as a buffer layer by vapor phase growth. When an active layer made of an SiC epitaxial growth layer is generated, crystal defects are not propagated to the active layer, and an active layer with very few crystal defects can be generated.

  Even when an inexpensive single crystal SiC substrate having a relatively large number of crystal defects is used as the single crystal SiC substrate, an active layer with few crystal defects can be generated because the crystal defects do not propagate to the active layer.

(Generation of active layer)
The single crystal SiC epitaxial layer of the example was used as a buffer layer, and an active layer composed of a second single crystal SiC epitaxial growth layer was formed thereon by vapor phase growth.

Specifically, H ₂ (hydrogen) 50 SLM as a carrier gas, C ₃ H ₈ (propane) as a carbon raw material, SiH ₄ (silane) as a silicon raw material, N ₂ (nitrogen) as an n-type dopant, carbon / silicon The ratio (C / S) is 1.1, the growth temperature is 1650 ° C., the pressure is 6.7 × 10 ³ Pa, and a single crystal SiC epitaxial growth layer is formed on the buffer layer by the step-controlled epitaxial method (vapor phase growth method). The active layer was formed. As a result, an active layer with a carrier concentration of 4 × 10 ^{15 to} 6 × 10 ¹⁵ cm ⁻² and a thickness of about 10 μm and few crystal defects was obtained.

  Since such a single crystal SiC epitaxial substrate has an active layer with few crystal defects, it can be suitably used for light emitting diodes, various semiconductor diodes, electronic devices, and the like.

1 Single crystal SiC substrate
2 Si plate
3, 3 'carbon atom supply substrate
4, 4 'spacer
5, 7 space
6 Cobblestone
8 containers

Claims (7)

A single crystal SiC is epitaxially grown on the single crystal SiC substrate by performing a heat treatment with a Si melt layer having a predetermined thickness interposed between the single crystal SiC substrate and the carbon atom supply substrate. The growth method of
The single-crystal SiC growth method includes a degassing / dehydration process for removing gas / water in the reaction system, a Si heating process for raising the temperature to a temperature higher than the melting point of Si, and a Si melting process at a temperature higher than the melting point of Si. A Si melting step for forming a liquid, and a SiC growth step for epitaxially growing single crystal SiC on a single crystal SiC substrate at an epitaxial growth temperature,
The Si temperature raising step is a first temperature raising step in which the temperature is raised to a predetermined temperature in the vicinity of the Si melting point that does not exceed the Si melting point at a predetermined heating rate that keeps the in-plane temperature of the single crystal SiC substrate constant. If, Ri do from the second heating step of raising the temperature from a predetermined temperature of the Si melting point near that does not exceed the Si melting point to Si melting point or higher,
After the completion of the SiC growth step, an evaporation process for completely evaporating the Si melt is performed .   The method for growing single crystal SiC according to claim 1, wherein a temperature increase rate in the second temperature increase step is faster than a temperature increase rate in the first temperature increase step. 3. The method for growing single crystal SiC according to claim 1, wherein the evaporation process is a process of evaporating Si melt while maintaining the epitaxial growth temperature. 3. The method for growing single crystal SiC according to claim 1, wherein the evaporation process is a process of evaporating a Si melt in a temperature range from the epitaxial growth temperature to the Si melting point. Wherein the single crystal SiC substrate in which the end of the evaporation process, any one of claims 1 to 4, characterized in that the temperature lowering processing temperature is lowered at a predetermined temperature lowering rate to relieve single crystal SiC thermal stress of the substrate 1 The method for growing single crystal SiC according to the item. A buffer layer comprising a single crystal SiC substrate and a first single crystal SiC epitaxial layer formed on the single crystal SiC substrate by the single crystal SiC growth method according to any one of claims 1 to 5. And a single crystal SiC epitaxial substrate comprising an active layer made of a second single crystal SiC epitaxial growth layer formed on the buffer layer. A method for producing a single crystal SiC epitaxial substrate according to claim 6 ,
A first single crystal SiC epitaxial layer generation step for generating a first single crystal SiC epitaxial layer on a single crystal SiC substrate by the single crystal SiC growth method according to any one of claims 1 to 5. ,
And a second single crystal SiC epitaxial layer generating step of generating a second single crystal SiC epitaxial layer by vapor deposition on the first single crystal SiC epitaxial layer. Manufacturing method.

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