JP2002293694A - Silicon carbide single crystal ingot and method of manufacturing for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicon carbide single crystal out of which a single crystal silicon carbide wafer of a low defect and large caliber can be taken. SOLUTION: In growing the silicon carbide single crystal by a sublimation recrystallization method using a seed crystal, one or >=2 kinds of the gases selected from hydride of silicon, hydride of carbon or hydride containing silicon and carbon are incorporated into atmosphere inert gas and the silicon carbide single crystal is grown, by which the silicon carbide single crystal ingot having high quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon carbide single crystal and a method of manufacturing the same, and more particularly, to a high-quality large-sized single crystal ingot to be used as a substrate wafer for a blue light emitting diode or an electronic device, and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art Silicon carbide (SiC) has attracted attention as an environment-resistant semiconductor material because of its physical and chemical properties such as excellent heat resistance and mechanical strength, and resistance to radiation. SiC
Is a representative substance having a polymorphic (polytype) structure having many different crystal structures even though the chemical composition is the same. Polytype means that when a molecule in which Si and C are bonded is considered as one unit in the crystal structure, the periodic structure when these unit structure molecules are stacked in the c-axis direction ([0001] direction) of the crystal is different. Caused by Typical polytypes include 6H type, 4H type, 15R type and 3C type. Here, the first number indicates the repetition period of the lamination, and the alphabet indicates a crystal system (H is a hexagonal system, R is a rhombohedral system, and C is a cubic system). Each polytype has different physical and electrical characteristics, and the application to various uses is considered by utilizing the difference. For example, 6H
In recent years, 4H has been used as a substrate for short wavelength optical devices from blue to ultraviolet, and 4H is considered to be used as a substrate wafer for high frequency high voltage electronic devices and the like.

However, high quality S having a large area
A crystal growth technique capable of stably supplying an iC single crystal on an industrial scale has not yet been established. Therefore, SiC
Has been hampered in practice despite the semiconductor materials having many advantages and possibilities as described above.

Conventionally, on a laboratory scale, a SiC single crystal is grown by, for example, a sublimation recrystallization method (Rayleigh method).
An SiC single crystal of a size that allows the manufacture of a semiconductor device has been obtained. However, in this method, the area of the obtained single crystal is small, and it is difficult to control the size and shape with high precision. Further, it is not easy to control the crystal polymorphism and impurity carrier concentration of SiC. Further, a cubic SiC single crystal is also grown by heteroepitaxial growth on a heterogeneous substrate such as silicon (Si) using a chemical vapor deposition method (CVD method). In this method, a single crystal having a large area is obtained, by such lattice mismatch with the substrate is also about 20 percent, thereby only grown SiC single crystal containing a large amount of defects (~10 ⁷ cm ^-2) And it is not easy to obtain a high quality SiC single crystal. To solve these problems, Si
An improved Rayleigh method for performing sublimation recrystallization using a C single crystal wafer as a seed crystal has been proposed (Yu. MT).
airov and V.A. F. Tsvetkov, Jo
urnal of Crystal Growth, v
ol. 52 (1981) pp. 146-150). In this method, since a seed crystal is used, the nucleation process of the crystal can be controlled, and the atmospheric pressure can be reduced by 10% with an inert gas.
By controlling the pressure from 0 Pa to about 15 kPa, the crystal growth rate and the like can be controlled with good reproducibility. The principle of the improved Rayleigh method will be described with reference to FIG. The SiC single crystal serving as a seed crystal and the SiC crystal powder serving as a raw material are housed in a crucible (usually graphite), and are placed in an inert gas atmosphere (133 Pa to 13.3 kPa) such as argon (2000 Pa to 2000 Pa).
Heated to 400 degrees. At this time, the temperature gradient is set so that the seed crystal is slightly lower in temperature than the raw material powder. Raw material, after sublimation, concentration gradient (formed by temperature gradient)
As a result, it is diffused and transported in the seed crystal direction. Single crystal growth is realized by recrystallization of the source gas that has reached the seed crystal on the seed crystal.

At this time, the resistivity of the crystal is determined by adding an impurity gas to an atmosphere of an inert gas,
It can be controlled by mixing the impurity element or its compound in the raw material powder. Typical examples of the substitutional impurities in the SiC single crystal include nitrogen (n-type), boron,
There is aluminum (p-type). The SiC single crystal can be grown while controlling the carrier type and the concentration.

In the modified Rayleigh method, the crystal growth rate is 1 hour / hour.
mm or more, which is advantageous in terms of productivity. However, when a SiC single crystal is manufactured by the improved Rayleigh method, since the sublimation phenomenon is used,
Various gas molecules sublimated from raw materials (mainly Si, SiC ₂ ,
It is difficult to arbitrarily control the composition of Si ₂ C), and if the growth temperature changes due to a change in characteristics of a heat insulating material or the like during long-term crystal growth, a stable gas composition ratio is secured. There was a problem that it was not possible. Si / in gas
A change in the C composition ratio during growth increases growth instability and causes deterioration of crystal quality such as polycrystal generation. Further, when the Si / C composition ratio in the sublimation gas changes, the type of polytype that is likely to be generated changes (Yu.
A. Vodakov, G .; A. Lomakina an
dE. N. Mokhov, Soviet Physi
cs-Solid State vol. 24 (5)
(1982) pp. 780-784), and a polytype crystal phase different from the polytype crystal used as the substrate is likely to be generated. At this time, micropipe defects were generated from the interface of the different polytypes, which caused crystal quality deterioration (micropipe defect density of 100 / cm ² or more).

On the other hand, as a growth method capable of controlling the Si / C composition ratio in the gas described above, there is a high-temperature chemical vapor deposition method (hereinafter, referred to as a high-temperature CVD method) used as a method for producing a single crystal thin film. The high-temperature CVD method is a method in which a source gas having a composition containing silicon and carbon is reacted at a high temperature. The high-temperature CVD method has an advantage that the Si / C ratio of the entire gas system can be optimized and can be kept constant during the growth time. This is because the molecular structure of the gas used for the reaction can be selected, and the Si / C ratio can be controlled by adjusting the flow rates of the Si-containing gas and the C-containing gas. On the other hand, the disadvantage is that the growth rate is as low as 0.5 mm / hour or less, and the method cannot be applied to a large bulk single crystal production method because of low productivity even though it can be used for thin film production. In order to increase the growth rate by the high-temperature CVD method, it is necessary to increase the flow rate of the source gas. However, in this case, the heat insulating property deteriorates due to the reaction between the raw material gas and the heat insulating material, and it becomes difficult to grow crystals for a long time,
After all, productivity is deteriorated.

[0008]

As described above, in the conventional single crystal growth technique (improved Rayleigh method), the S
In the iC single crystal, different polytypes (6H type, 4H
H-type, 15R-type, etc.) were easily mixed, and a large amount of micropipe defects (100 or more in density / cm ² or more) generated from the interface between different polytypes was included. Tair
ov et al. , J. et al. Cryst. Growth
43 (1976) pp. As described in 209-211, in the growth by the improved Rayleigh method, the mixture of heterogeneous polytypes in an ingot cannot be suppressed. Further, when such heterogeneous polytypes are generated, the micropipe defects generated at the interface are the same as those described in P.I. G. FIG. Neu
deck et al. , IEEE Electron
Device Letters, vol. 15 (19
94) pp. As described in JP-A-63-65, it is said that a leakage current or the like is caused when an element is manufactured.

The present invention has been made in view of the above circumstances, and has been made in consideration of the above circumstances. It is an object of the present invention to provide a SiC capable of producing high-quality large-diameter {0001} wafers having few defects with good reproducibility while securing an industrially sufficient growth rate. An object of the present invention is to provide a method for producing a single crystal and a SiC single crystal ingot obtained from the method.

[0010]

The method for producing a SiC single crystal according to the present invention comprises the steps of (1) heating a raw material SiC and growing a single crystal on a seed crystal by a sublimation recrystallization method.
A method for producing an iC single crystal, comprising introducing a reactive gas containing silicon and / or carbon into an inert gas atmosphere,
A method for producing a silicon carbide single crystal, wherein a SiC single crystal is grown on a seed crystal; (2) the reactive gas is selected from hydrocarbons, hydrides of silicon or hydrides of silicon and carbon (1) The method for producing a SiC single crystal according to (1), which is a seed or two or more gases, (3) the hydride gas of silicon is silane (SiH ₄ ), and the partial pressure thereof is 1.
(2) The method for producing a SiC single crystal according to (2), wherein the hydrocarbon is propane (C ₃ H ₈ ).
And / or Si as described in (2), which is ethylene (C ₂ H ₄ ).
(5) The method for producing a SiC single crystal according to (2), wherein the hydride of silicon and carbon is tetramethylsilane (Si (CH ₃ ) ₄ ), (6) the method for producing a hydrocarbon or The partial pressure of the hydride of silicon and carbon is 0.1
The method for producing a silicon carbide single crystal according to (4) or (5), wherein the method is in the range of 33 to 66.5 Pa;
A silicon carbide single crystal ingot obtained by any one of the production methods according to (6), wherein the diameter of the ingot is 50.
mm or more, the entire ingot is composed of a single polytype, and the micropipe defect density is 30 pieces / cm.
Silicon carbide single crystal ingot, characterized in that it is ² or less, (8) (7) cutting the silicon carbide single crystal ingot according to, polished comprising silicon carbide single crystal substrate, (9)
A silicon carbide epitaxial wafer formed by epitaxial growth on the silicon carbide single crystal substrate according to the above (8).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The manufacturing method of the present invention is characterized in that a hydride containing silicon, a hydride containing carbon, or a hydride containing both silicon and carbon is introduced during growth to thereby obtain Si / By optimizing the C ratio, high quality S
An iC single crystal can be stably manufactured while maintaining a sufficient growth rate.

The effect of the present invention will be described with reference to FIG.

The gas to be introduced is introduced into the growth apparatus from a gas cylinder through a pipe. The partial pressure of various gases used in the experiment is a value obtained by multiplying the total pressure during growth (adjusted by a pressure control valve provided on the gas exhaust side) by the gas flow ratio of each gas type used.

When an SiC single crystal is grown by the improved Rayleigh method, a stable temperature distribution is maintained between the raw material and the seed crystal in the initial stage of growth because the heat insulating property of the crucible heat insulating material is good. I have. However, as the growth time elapses, the heat insulating properties of the heat insulating material gradually deteriorate due to the influence of the sublimation gas. For this reason, the temperature of the crucible drops,
Alternatively, the Si / C ratio in the gas changes as the temperature distribution between the raw material and the seed crystal changes. The vapor pressure curves of various gas molecules (mainly Si, SiC ₂ , and Si ₂ C are generated) sublimated from the SiC raw material are shown in FIG. O. Konstantino
v, EMIs Dataviews Series
13 (1995) pp. 170-203, it has been found that in a temperature range of 1950 ° C. to 2380 ° C., the lower the temperature, the higher the Si / C. As a result, the Si / C ratio in the gas changes due to a decrease in temperature due to the deterioration of the heat insulating material during growth, and the growth conditions change due to this, and a polytype phase different from the seed crystal is likely to be generated. Become. Here, Si / C in the gas due to deterioration of the heat insulating material
By increasing the ratio, that is, by introducing an appropriate amount of carbon hydride gas during the growth in a form to compensate for the decrease in C in the sublimation gas,
Stable Si / C by suppressing change of Si / C ratio during growth
Crystal growth can be sustained under the condition of the ratio, the generation of different polytype phases can be suppressed, and a high-quality single crystal with few defects can be obtained.

When the Si / C composition ratio in the sublimation gas changes, the type of polytype which is likely to be generated changes (Y
u. A. Vodakov, G .; A. Lomakina
andE. N. Mokhov, Soviet Physs
ics-Solid State vol. 24 (5)
(1982) pp. 780-784), on the contrary, can be used as a technique for obtaining a certain polytype phase more stably by intentionally controlling the Si / C composition ratio. Specifically, when the Si / C ratio in the gas becomes larger than that of the normal growth condition, the condition is such that the 6H polytype easily grows stably. Conversely, C
When the phase shifts to a state with a large amount, the 4H polytype phase is easily generated stably. By taking advantage of this effect,
A polytype identical or completely different from the seed crystal can be stably obtained.

The ability to control the Si / C composition ratio in the sublimation gas has the same advantages as the high-temperature CVD method. However, the high-temperature CVD method uses a hydride of silicon, a hydride of carbon, or silicon and carbon. Is a method of introducing only a gas such as a hydride containing a. In this case, only the introduced gas does not supply a sufficient raw material, and the crystal growth rate is 0.5 mm / h.
It becomes smaller as follows. If the growth rate is to be increased by increasing the flow rate of the gas, the heat insulating property is degraded due to the reaction between the gas and the heat insulating material, and stable crystal growth over a long period of time becomes difficult. In contrast, the method uses a sublimation gas from a solid raw material to secure a large crystal growth rate of 1 mm / hour or more, and then obtains a hydride of silicon, a hydride of carbon, or a hydrogen containing silicon and carbon. By introducing a small amount of a compound gas, it is possible to intentionally control the Si / C composition ratio in the gas. That is,
In the present invention, by controlling the Si / C composition ratio in the sublimation gas at the time of growth, which has an industrially large growth rate,
It is possible to suppress the occurrence of different types of polytypes and the accompanying micropipe defects, and to obtain a high-quality SiC single crystal over the entire crystal area.

Regarding the total pressure of the reaction system in the present invention,
A range of 665 Pa to 66.5 kPa is desirable. This pressure
Growth outside the force range is too fast for crystal growth
The system is difficult to control (lower pressure) or the growth rate is low.
Not useful industrially because it is too low (higher pressure)
It is not useful from a practical point of view. Used in the present invention
As the hydride of carbon, C_TwoH_Four, C_ThreeH₈, C_TwoH_TwoBut profit
It is mentioned as a usable gas. Also, hydrides of silicon
As SiH_Four, Si_TwoH₆Is mentioned. further,
Examples of hydrides containing silicon and carbon include SiH_Two(C
H_Three)_Two, SiH (CH_Three)_Three, Si (CH_Three)_FourIs mentioned
You. Among these, the ease of gas handling (stability, raw
From the point of view of productivity)_Two
H_FourAnd C_ThreeH₈, Silicon hydride is SiH_Four, Silicon and
For hydrides containing carbon, Si (CH_Three) _FourBut most practical
Are suitable. The partial pressure during the growth of the introduced gas
1.33 to 66.5 Pa for hydrogen hydride gas,
Partial pressure of hydride gas, hydride gas containing silicon and carbon
Is preferably in the range of 0.133 to 66.5 Pa.
The gas partial pressure of silicon hydride becomes 66.5 Pa or more
And the Si / C composition ratio in the sublimation gas becomes excessive Si.
When Si droplets are generated on the crystal growth surface,
This causes the formation of ip defects and polycrystalline phases. Also carbon water
When the partial pressure of the iodide gas becomes 66.5 Pa or more
On the other hand, if the carbon content becomes too large,
Oxides, micropipe defects and polycrystalline phase
It causes the occurrence of. Of hydride gas containing silicon and carbon
In this case, the same as in the case of the hydride gas of carbon, 66.5 Pa or more
At the partial pressure of
Cause. If the gas partial pressure is smaller than the specified value,
In this case, there is a possibility that the effect of introducing these gas components may not be obtained.
You.

By using the manufacturing method of the present invention, 5
It is possible to produce a SiC single crystal ingot having a large diameter of 0 mm or more and composed of a single polytype over the entire ingot. Further, it has a feature that micropipe defects adversely affecting the device are extremely small at 30 / cm ² or less.

The SiC single crystal wafer obtained by cutting and polishing the SiC single crystal ingot thus manufactured is 5
Since it has a diameter of 0 mm or more, when manufacturing various devices using this wafer, it is possible to use an industrially established conventional production line for semiconductor (Si, GaAs, etc.) wafers. Suitable for mass production.

Further, CV is placed on the SiC single crystal wafer.
An SiC single crystal epitaxial wafer produced by growing an epitaxial thin film by the D method or the like has excellent characteristics (surface morphology of the epitaxial thin film, Electrical characteristics, etc.).

[0021]

Embodiments of the present invention will be described below.

(Example 1) FIG. 2 shows a manufacturing apparatus according to the present invention, in which Si is formed by an improved Rayleigh method using a seed crystal.
It is an example of an apparatus for growing a C single crystal. First, the single crystal growth apparatus will be briefly described. Crystal growth is
It is performed by sublimating and recrystallizing the SiC powder raw material 2 on the SiC single crystal 1 used as the seed crystal. The seed crystal SiC single crystal 1 is attached to the inner surface of the graphite crucible lid 4 of the graphite crucible 3. The SiC powder raw material 2 is filled in a graphite crucible 3. Such a graphite crucible 3 is installed inside a double quartz tube 5 by a graphite support rod 6. Around the graphite crucible 3, a graphite felt 7 for heat shielding is provided. Double quartz tube 5
Is high vacuum evacuation (less than 10 ^-3 Pa) by vacuum evacuation device
And the internal atmosphere can be pressure-controlled by Ar gas. A work coil 8 is provided on the outer periphery of the double quartz tube 5, and the graphite crucible 3 can be heated by flowing a high-frequency current to heat the raw material and the seed crystal to desired temperatures. The temperature of the crucible was measured at the center of the felt covering the top and bottom of the crucible with a diameter of 2
An optical path of ４4 mm is provided, light is taken out from the upper and lower portions of the crucible, and a two-color thermometer is used. The temperature at the bottom of the crucible is the raw material temperature, and the temperature at the top of the crucible is the seed temperature. Various gases (silicon hydride, carbon hydride, hydride containing silicon and carbon) in addition to Ar gas for controlling the internal atmosphere are passed through a gas flow controller 10 to a gas pipe 9 to the manufacturing apparatus. be introduced.

Next, an example of the production of a SiC single crystal using this crystal growth apparatus will be described. First, as a seed crystal, a SiC single crystal wafer having a hexagonal system and a 4H polytype having a (000-1) C plane having a diameter of 50 mm was prepared. Next, the seed crystal 1 was attached to the inner surface of the graphite crucible lid 4 of the graphite crucible 3. S inside graphite crucible 3
iC powder raw material 2 was charged. Next, the graphite crucible 3 filled with the raw material is closed with a graphite crucible lid 4 fitted with a seed crystal, covered with a graphite felt 7, placed on a graphite support rod 6, and placed in a double quartz tube 5. Installed inside. Then, after evacuating the inside of the quartz tube, an electric current was applied to the work coil to raise the temperature of the raw material to 2000 degrees Celsius. Then, Ar gas was used as an atmosphere gas at a flow rate of 2.34 × 10 ⁻⁶ m ³ /
Ethylene (C ₂ H ₄ ) was 8.35 × as a sublimation gas composition ratio control gas (in this case, a hydrocarbon gas was used for the purpose of changing the composition ratio in a C-rich direction).
10 ⁻⁹ m ³ / sec (4.73 P as the partial pressure during growth)
a) The raw material temperature was raised to 2400 degrees Celsius, which is the target temperature, while maintaining the pressure inside the quartz tube at about 80 kPa. The pressure was reduced to a growth pressure of 1.3 kPa over about 30 minutes, and then growth was continued for about 20 hours. At this time, the temperature gradient in the crucible was 15 degrees Celsius / cm, and the growth rate was about 1 degree.
mm / hr. The diameter of the obtained crystal is 51 mm,
The height was about 20 mm.

The silicon carbide single crystal thus obtained was analyzed by X-ray diffraction and Raman scattering. As a result, it was confirmed that the single crystal of 4H had only the same polytype as that of the seed crystal, and the mixture of different polytypes was suppressed. It was confirmed that a silicon carbide single crystal of the type grew.

Next, the SiC single crystal ingot manufactured as described above was cut and polished to produce a SiC single crystal wafer having a thickness of 300 μm and a diameter of 51 mm. The plane orientation of the wafer is 3. in the <11-20> direction from the (0001) plane.
It was turned off five times. In order to evaluate micropipe defects, the wafer surface was etched with molten KOH at about 530 degrees Celsius, and the number of large hexagonal etch pits corresponding to the micropipe defects was examined with a microscope. It was found that the occurrence of defects other than pipe defects was completely suppressed, and some of them disappeared during the growth, and as a result, the defect density was reduced to 30 defects / cm ² or less.

Further, SiC was epitaxially grown by using the 51 mm diameter SiC single crystal wafer as a substrate. The growth conditions for the SiC epitaxial thin film are as follows:
The growth temperature was 1500 degrees Celsius, and the flow rates of silane (SiH ₄ ), propane (C ₃ H ₈ ), and hydrogen (H ₂ ) were each 5.0.
^{× 10 -9 m 3 /sec,3.3×10 -9 m} 3 / sec,
It was 5.0 × 10 ⁻⁵ m ³ / sec. The growth pressure was atmospheric pressure. The growth time is 2 hours and the film thickness is about 5m
m.

After the growth of the epitaxial thin film, the surface morphology of the obtained epitaxial thin film was observed with a Nomarski optical microscope. It was found that a SiC epitaxial thin film having the same had grown.

(Example 2) In this example, as a seed crystal,
A hexagonal system having a (0001) Si plane with a diameter of 50 mm,
A SiC single crystal wafer having a 6H polytype was prepared. Next, the seed crystal 1 was attached to the inner surface of the graphite crucible lid 4 of the graphite crucible 3. The inside of the graphite crucible 3 was filled with the SiC powder raw material 2. Next, the graphite crucible 3 filled with the raw material is closed with a graphite crucible lid 4 fitted with a seed crystal, covered with a graphite felt 7, placed on a graphite support rod 6, and placed in a double quartz tube 5. Installed inside. Then, after evacuating the inside of the quartz tube, an electric current was applied to the work coil to raise the temperature of the raw material to 2000 degrees Celsius. Thereafter, Ar gas was supplied as an atmosphere gas at a flow rate of 2.34 × 10 ⁻⁶ m ³ / sec.
c, 1.67 × 1 silane (SiH ₄ ) as a sublimation gas composition ratio control gas (in this case, silicon hydride gas is used for the purpose of changing the composition ratio in a Si-rich direction).
0 ^-8 m ³ / sec (9.43 Pa as partial pressure during growth)
While maintaining the pressure inside the quartz tube at about 80 kPa,
The raw material temperature was increased to the target temperature of 2400 degrees Celsius. The pressure was reduced to the growth pressure of 1.3 kPa over about 30 minutes, and then growth was continued for about 8 hours. At this time, the temperature gradient in the crucible was 15 degrees Celsius / cm, and the growth rate was about 1 mm / cm.
It was time. The diameter of the obtained crystal was 51 mm, and the height was about 8 mm.

When the silicon carbide single crystal thus obtained was analyzed by X-ray diffraction and Raman scattering, it was found that the silicon carbide single crystal had only the same polytype as that of the seed crystal, and that the 6H single poly in which different types of polytype were mixed was suppressed. It was confirmed that a silicon carbide single crystal of the type grew.

Next, the SiC single crystal ingot thus manufactured was cut and polished to produce a 300 μm thick, 51 mm diameter SiC single crystal wafer. The plane orientation of the wafer is 3. in the <11-20> direction from the (0001) plane.
It was turned off five times. In order to evaluate micropipe defects, the wafer surface was etched with molten KOH at about 530 degrees Celsius, and the number of large hexagonal etch pits corresponding to the micropipe defects was examined with a microscope. It was found that the occurrence of defects other than pipe defects was completely suppressed, and some of them disappeared during the growth, and as a result, the defect density was reduced to 30 defects / cm ² or less.

Further, SiC was epitaxially grown by using the 51 mm diameter SiC single crystal wafer as a substrate. The growth conditions for the SiC epitaxial thin film are as follows:
The growth temperature was 1500 degrees Celsius, and the flow rates of silane (SiH ₄ ), propane (C ₃ H ₈ ), and hydrogen (H ₂ ) were 5.0, respectively.
^{× 10 -9 m 3 /sec,3.3×10 -9 m} 3 / sec,
It was 5.0 × 10 ⁻⁵ m ³ / sec. The growth pressure was atmospheric pressure. The growth time is 2 hours and the film thickness is about 5 mm
grown.

After the epitaxial thin film was grown, the surface morphology of the obtained epitaxial thin film was observed with a Nomarski optical microscope. It was found that a SiC epitaxial thin film having the same had grown.

[0033]

As described above, according to the present invention,
In the improved Rayleigh method using a seed crystal, by introducing a hydride gas containing silicon hydride, carbon hydride or silicon and carbon, the Si / C composition ratio in the sublimation gas is controlled. A good quality silicon carbide single crystal with few defects can be grown with good reproducibility and uniformity while maintaining an appropriate growth rate. By using such a silicon carbide single crystal wafer, a blue light emitting element having excellent optical characteristics and a high withstand voltage / environmentally resistant electronic device having excellent electrical characteristics can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the improved Rayleigh method.

FIG. 2 is a configuration diagram illustrating an example of a single crystal growth apparatus used in the manufacturing method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 seed crystal (SiC single crystal) 2 SiC powder raw material 3 graphite crucible 4 graphite crucible lid 5 double quartz tube 6 support rod 7 graphite felt 8 work coil 9 gas pipe 10 gas flow controller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Fujimoto 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (72) Inventor Takashi Aigo 20-1 Shintomi, Futtsu-shi, Chiba New Japan (72) Inventor Hirokatsu Yashiro 20-1 Shintomi, Futtsu-shi, Chiba F-term in the Technology Development Division of Nippon Steel Corporation (reference) 4G077 AA02 BE08 DA18 EA08 SA01 SA07

Claims (9)

[Claims] 1. A method for producing a silicon carbide single crystal, comprising a step of heating a raw silicon carbide and growing a single crystal on a seed crystal by a sublimation recrystallization method, wherein silicon and / or silicon and / or A method for producing a silicon carbide single crystal, comprising introducing a reactive gas containing carbon to grow a silicon carbide single crystal on a seed crystal. 2. The method for producing a silicon carbide single crystal according to claim 1, wherein said reactive gas is one or more gases selected from hydrocarbons, hydrides of silicon or hydrides of silicon and carbon. . 3. The hydride gas of silicon is silane (Si)
3. The method for producing a silicon carbide single crystal according to claim 2, wherein H ₄ ) has a partial pressure of 1.33 to 66.5 Pa. 4. 4. The method according to claim 1, wherein the hydrocarbon is propane (C_ThreeH₈)as well as
/ Or ethylene (C _TwoH_Four3. The silicon carbide according to claim 2, wherein
Method for producing elementary single crystal. 5. The method for producing a silicon carbide single crystal according to claim 2, wherein the hydride of silicon and carbon is tetramethylsilane (Si (CH ₃ ) ₄ ). 6. The method for producing a silicon carbide single crystal according to claim 4, wherein a partial pressure of the hydrocarbon or the hydride of silicon and carbon is 0.133 to 66.5 Pa. 7. A silicon carbide single crystal ingot obtained by any one of the production methods according to claim 1, wherein the ingot has a diameter of 50 mm or more, and the entire ingot is a single polytype. A silicon carbide single crystal ingot, which is constituted and has a micropipe defect density of 30 / cm ² or less. 8. A silicon carbide single crystal substrate obtained by cutting and polishing the silicon carbide single crystal ingot according to claim 7. 9. A silicon carbide epitaxial wafer formed by epitaxial growth on the silicon carbide single crystal substrate according to claim 8.