JP2003104799A - Silicon carbide single crystal ingot and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicon carbide single crystal ingot suppressing degradation of crystal quality while securing polytype conversion of silicon carbide single crystal at a sufficient growing speed, and having a plurality of polytypes in the direction of crystal growing of a single crystal ingot, an epitaxial wafer obtained from the ingot, and a method of manufacturing the ingot. SOLUTION: The silicon carbide single crystal ingot is characterized in that the ingot contains at least one layer containing a different element, the wafer obtained from the ingot, and the method of manufacturing the ingot.

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 large-sized single crystal ingot of high quality that serves as a substrate wafer for blue light emitting diodes and electronic devices and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art Silicon carbide (SiC) is excellent in heat resistance and mechanical strength, and is attracting attention as an environment-resistant semiconductor material because of its physical and chemical properties such as resistance to radiation. SiC
Is a typical substance having a polymorphic crystal (hereinafter, also referred to as polytype) structure which has many different crystal structures even if the chemical composition is the same. The polytype is that, when a molecule in which Si and C are bonded in the crystal structure is considered as one unit, the periodic structure when the unit structure molecule is laminated in the c-axis direction ([0001] direction) of the crystal is different. Caused by. Representative polytypes include 6H, 4H, 15R or 3C. Here, the first number indicates the stacking cycle,
The alphabets represent crystal systems (H is hexagonal, R is rhombohedral, and C is cubic). Each polytype has different physical and electrical characteristics, and it is considered to be applied to various applications by utilizing the difference. For example, 6H has recently been used as a substrate for short-wavelength optical devices from blue to ultraviolet, and 4H is considered to be applied as a substrate wafer for high-frequency and high-voltage electronic devices.

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
Despite its many advantages and potentials mentioned above, its practical use has been hindered.

[0004] Conventionally, it has been reported that a SiC single crystal having a size capable of producing a semiconductor device on a laboratory scale can be obtained by growing a SiC single crystal by, for example, a sublimation recrystallization method, a so-called Rayleigh method. Has been done. However, in this method, the area of the obtained single crystal is small,
It is difficult to control the size and shape with high accuracy, and it is not easy to control the crystal polymorphism and the impurity carrier concentration of SiC. In addition, a cubic silicon carbide single crystal is also grown by heteroepitaxial growth on a heterogeneous substrate made of, for example, silicon using a chemical vapor deposition method (CVD method). With this method, a large-area single crystal can be obtained, but there are many defects (~ 10 ⁷⁾ such as a lattice mismatch of about 20% with the substrate.
Since only a SiC single crystal containing cm ⁻² ) can be grown, it is not easy to obtain a high quality SiC single crystal.

In order to solve these problems, SiC
An improved Rayleigh method has been proposed in which sublimation recrystallization is performed using a single crystal {0001} wafer as a seed crystal (Yu.
M. Tairov and VF Tsvetkov, Journal of Crystal Gro
wth, vol. 52 (1981) pp. 146-150). in this way,
Since a seed crystal is used, the nucleation process of the crystal can be controlled,
Also, the atmosphere pressure is changed from 100 Pa to 15 by using an inert gas.
By controlling to about kPa, the crystal growth rate and the like can be controlled with good reproducibility. The principle of the modified Rayleigh method will be described with reference to FIG. The SiC single crystal serving as the seed crystal and the SiC crystal powder serving as the raw material are housed in a crucible (usually graphite) and placed in an atmosphere of an inert gas such as argon (133-1).
3.3 kPa), and heated to 2000-2400 ° C.
At this time, the temperature gradient is set so that the seed crystal is slightly lower in temperature than the raw material powder. After sublimation, the raw material is diffused and transported in the seed crystal direction by a concentration gradient (formed by a temperature gradient). Single crystal growth is realized by recrystallizing the source gas that has reached the seed crystal on the seed crystal. On this occasion,
The crystal resistivity is determined by adding an impurity gas into an atmosphere of an inert gas or mixing an impurity element or its compound into the SiC raw material powder to determine the position of silicon or carbon atoms in the SiC single crystal structure as an impurity. It can be controlled by substituting with an element (doping).
Typical substitutional impurities in SiC single crystal,
There are nitrogen (n-type), boron, and aluminum (p-type).
A SiC single crystal can be grown while controlling the carrier type and concentration.

Currently, the S produced by the improved Rayleigh method described above is used.
A SiC single crystal wafer having a diameter of 2 inches (50 mm) to 3 inches (75 mm) is cut out from the iC single crystal, and is used for epitaxial thin film growth and device fabrication.

As described above, SiC exhibits various polytype structures. Among them, 4H is useful because it has excellent characteristics (dielectric breakdown electric field strength, electron mobility) as a substrate wafer for high frequency and high voltage electronic devices. Is. In order to produce 4H using the modified Rayleigh method, 4
H must be used. However, in the production method before the improved Rayleigh method (Rayleigh method, etc.), most of the obtained single crystals are 6H or 15R, and the yield of 4H is extremely small, so that a substrate having a size usable as a seed crystal is obtained. I can't. Therefore, in order to obtain a 4H seed crystal,
In the growth using the 6H seed crystal by the modified Rayleigh method, there was no choice but to adopt a method of converting the polytype to 4H by some method. Therefore, from such circumstances, it has been an important issue to establish a technique for surely performing polytype conversion from 6H to 4H. However, in the production of SiC single crystal by the modified Rayleigh method, 6H to 4H
Growth conditions capable of stable conversion to H and suppressing the deterioration of crystal quality to perform polytype conversion have not yet been established.

For example, KF Knipppenberg, Philips Re
As reported in search Reports vol.18 (1963) pp.161-274, the growth temperature during crystal growth is low (2000 ° C).
The occurrence probability of 4H can be increased by setting the following. However, there is a problem in productivity because the crystal growth rate is significantly reduced at low temperatures.

In addition, Yu. A. Vodakov, GA Lomakina a
nd EN Mokhov, Soviet Physics-Solid State vol.24
(5) As reported in (1982) pp. 780-784, it is also possible to add scandium, which is a transition element, to the raw material.
The probability of H-type occurrence can be increased. However, in this case, since metal impurities are mixed in the crystal, there is a problem that the device characteristics are adversely affected when, for example, a semiconductor device is manufactured (for example, a deep trap level is formed in the forbidden band to deteriorate the characteristics of the device). Become.

[0010]

As described above, 4H SiC produced by converting 6H by using the conventional technique.
The single crystal has problems that the growth rate is low and that adverse effects due to mixing of metal impurities cannot be avoided during device fabrication.

Therefore, the present invention has been made in view of the above circumstances, and it is one of the single types obtained by polytype conversion of SiC single crystal by suppressing the crystal quality deterioration while ensuring a sufficient growth rate. Provided are a SiC single crystal ingot having a plurality of polytypes in the crystal growth direction of the crystal ingot, and a method for producing the same.

[0012]

That is, the present invention is as follows.
(1) A silicon carbide single crystal ingot having at least one different element-containing layer in the silicon carbide single crystal ingot, (2) The different element contained in the different element-containing layer is nitrogen, boron, The silicon carbide single crystal ingot according to (1), which is aluminum or nitrogen and boron, and (3) the content of the different element in the different element containing layer is 1 × 10 ¹⁷ to 1 × 10 ²⁰ atom / cm. ^{Is 3} ,
(1) or the silicon carbide single crystal ingot according to (2), (4) any one of (1) to (3), wherein the polytypes of the silicon carbide single crystals adjacent to each other through the different element containing layer are different. The silicon carbide single crystal ingot according to the item (5) 5,
The silicon carbide single crystal ingot according to any one of (1) to (4), which has a diameter of 0 mm or more, (6) (1).
(7) A silicon carbide single crystal substrate obtained by cutting and polishing the silicon carbide single crystal ingot according to any one of (5) to (5).
A silicon carbide epitaxial wafer epitaxially grown on the silicon carbide single crystal substrate according to (6), and (8) a step of heating a raw material silicon carbide to grow a single crystal on a seed crystal by a sublimation recrystallization method ( The method for manufacturing a silicon carbide single crystal ingot according to any one of 1) to (5), wherein a different element other than a crystal constituent element is introduced for a predetermined period of crystal growth during the single crystal growth to obtain a different material. A method for manufacturing a silicon carbide single crystal ingot, which comprises forming at least one element-containing layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a SiC single crystal having at least one different element-containing layer, which is obtained by polytype conversion of a SiC single crystal while suppressing a crystal quality deterioration while ensuring a sufficient growth rate. A crystal ingot, preferably a SiC single crystal ingot having a plurality of polytypes in one single crystal ingot, an epitaxial wafer made of the ingot, and a method for producing the ingot. The polytype conversion method in the present invention is characterized by introducing a strain into the crystal structure by forming an interface between a layer to which a different element is added and a non-added layer on the surface of the grown crystal during crystal growth. According to this polytype conversion method, a SiC single crystal having a target polytype (polytype different from that of the seed crystal) can be produced. Furthermore, after growing to the target thickness, polytype conversion can be performed by reintroducing strain into the crystal structure, so high-quality single crystal wafers with multiple polytypes can be obtained from one high-quality seed crystal. Since it is obtained, it can be said that the method for producing a SiC single crystal ingot of the present invention is an excellent crystal growth method capable of realizing an improvement in production yield. The above-mentioned different elements are preferably nitrogen, boron, aluminum,
Or nitrogen and boron.

The effects of the present invention will be described below with reference to FIGS. SiC is a typical material having a polytype structure that has many different crystal structures even if the chemical composition is the same. The SiC single crystal has a structure in which Si and C are bound to each other in a regular tetrahedral arrangement with a composition ratio of 1: 1. When considering a molecule in which Si and C are bonded in the crystal structure as one unit, the polytype has a different periodic structure when these unit structure molecules are stacked in the c-axis direction ([0001] direction) of the crystal. Occurs.

FIG. 2 shows typical polytypes 4H and 6H.
2A and 2B are schematic diagrams of crystal unit structures of both polytypes. The length in the a-axis direction and the length in the c-axis direction in the rectangular figure in FIG. 2 represent the distance between the Si or C atoms in the crystal unit structure in each axis direction. Due to the difference in the laminated structure between both polytypes, the value of the lattice constant, which is the basic unit of the crystal structure, in the c-axis direction and the a-axis direction ([11-20] direction)
The ratio of the values of is slightly different (a = 0.3 at 6H).
081 nm, c = 1.5120 nm, 4H, a = 0.
3080 nm, c = 1.0084 nm). In FIG. 2, (c
/ N) / a (where n is the number of layers in the unit lattice when the Si—C bond molecule is one unit, and the value obtained by dividing the lattice constant by this number of layers is the c-axis in the unit SiC molecular layer. 4H is 6H as shown as the value of (direction length)
It has a structure extending in the c-axis direction.

When a SiC single crystal is grown on a {0001} face seed crystal of a 6H polytype SiC single crystal by a sublimation recrystallization method, if aluminum is added as a different element during the growth, the aluminum reaching the growth surface is reached. Atoms are incorporated by substituting silicon atom positions in the crystal structure. Here, since the atomic radius of aluminum atoms is larger than that of silicon atoms, the crystal structure is either in the c-axis direction (the crystal growth direction) or in the a-axis direction (direction perpendicular to the crystal growth direction). The force to expand also works. At this time, since the growth surface is a free surface in the c-axis direction which is the growth direction, there is no restriction on the expansion, but the expansion in the a-axis direction does not cause any restriction on the expansion. Due to the (aluminum-free structure), expansion is suppressed. In other words, it receives the same force as if it were contracted in terms of the size to be expanded. As a result, as shown in FIG. 3, due to the influence of the expansion in the a-axis direction being suppressed (contracted), the corresponding amount c
The rate of increase in the amount of expansion in the axial direction increases, and c of the crystal structure
/ A ratio increases. Therefore, the crystal structure immediately after doping becomes a structure close to 4H, and conversion to 4H is induced by the structural change. The SiC single crystal growth is performed by a spiral growth mechanism caused by a screw dislocation, and step flow growth in which a spiral step is supplied from the facet formed on the outermost growth surface toward the entire crystal surface proceeds. Therefore, if the above-mentioned crystal structure conversion occurs on the facet, the structure of the step supplied from the facet is converted to 4H, so that polytype conversion over the entire surface is realized.

When the 6H seed crystal is doped with nitrogen as a different element, the nitrogen atom is incorporated by substituting the carbon position in the crystal structure. In this case, since the atomic radius of nitrogen is smaller than that of carbon, the doped crystal structure has a small lattice constant in both c and a axis directions. When the doping is stopped after forming such a nitrogen-added layer, the crystal structure has a c-axis direction (a crystal growth direction) and an a-axis direction (a direction perpendicular to the crystal growth direction) as shown in FIG. The force to expand in either direction works. In this case as well, the expansion in the c-axis direction, which is the growth direction, is unlimited, but the expansion in the a-axis direction is suppressed by the influence of the underlying doping layer having a small lattice constant. Due to this effect, the rate of increase in the amount of expansion in the c-axis direction increases, and c / a of the crystal structure is increased.
The ratio increases. Therefore, the crystal structure immediately after the doping is stopped becomes a structure close to 4H, and the conversion to 4H is induced by the structural change.

In the above examples, both cases of conversion from 6H to 4H polytype are shown, but by the method of exchanging different elements (nitrogen and aluminum in the above example are reversed).
Conversion in the opposite direction is also possible, i.e. conversion from 4H to 6H polytype. Also, conversion between the 15R polytype and the 6H polytype, which has a structure contracted in the c-axis direction further than the 6H polytype, is possible by the above method.

As described above, strain is introduced into the crystal structure by forming an interface between a layer to which a different element is added and a non-added layer on the surface of the grown crystal during growth, and a polytype structure different from that of the seed crystal ( Heterogeneous polytypes can be generated by a method of approaching the c / n) / a ratio. Further, the entire surface is converted into the different polytype only during a certain time zone during one growth, and then the original polytype is restored again, and the polytypes of the silicon carbide single crystals adjacent to each other through the different element containing layer are different from each other.
It is also possible to create a C single crystal ingot. This makes it possible to produce a SiC single crystal ingot having a plurality of polytypes in one single crystal ingot while suppressing the deterioration of crystal quality, and to obtain a high quality single crystal for a plurality of different polytypes from one high quality seed crystal. The production yield can be improved in that a wafer can be obtained. Further, in the present method, it is not necessary to set the growth temperature low when converting the polytype, and the crystal growth rate does not decrease, so that it is possible to secure sufficient productivity.

Regarding the above-mentioned effects of the present invention, the above-mentioned nitrogen or aluminum is also preferable, but the use of a different element is also effective. For example, when doping with a boron atom, the atom replaces a silicon atom in the crystal structure, and since the boron atom has a smaller atomic radius than the silicon atom, it is possible to exhibit the same effect as nitrogen. Regarding doping, it is also possible to use two kinds of different elements having the same effect at the same time.

Further, according to the method of the present invention, a single crystal ingot having a structure in which polytypes of silicon carbide single crystals adjacent to each other through the different element containing layer are different, for example, a structure in which 6H and 4H are laminated at arbitrary intervals Can be manufactured, and its application to various electronic device structures can be considered.

The SiC single crystal ingot produced by the production method of the present invention is characterized by having a large diameter of 50 mm or more and having at least one layer having a single polytype over the entire surface. An SiC single crystal substrate produced by cutting and polishing this SiC single crystal ingot, and S in which a high quality SiC epitaxial layer was produced on the substrate.
Regarding the iC epitaxial wafer, a high-quality large-diameter wafer suitable for the application can be supplied with high productivity as a substrate for a short-wavelength optical device in the blue to ultraviolet range or a substrate wafer for a high-frequency high-voltage electronic device or the like.

Further, the present invention is a method for producing a SiC single crystal ingot as described above, which comprises the step of heating a raw material silicon carbide to grow a single crystal on a seed crystal by a sublimation recrystallization method. A different element other than the constituent elements of the crystal is introduced on the way for a predetermined period of crystal growth to form at least one different element-containing layer.

In the production method of the present invention, a doping gas containing a different element is used for introducing and stopping the introduction of the different element. The target heterogeneous element-containing / non-containing interface is formed by introducing and stopping the introduction of a doping gas into an inert gas used for pressure control during growth. The doping concentration is usually 1 × 1 even in undoped (particularly when grown without using a doping gas) growth due to the restrictions such as the purity of raw materials.
Since the nitrogen atom concentration is about 0 ¹⁶ atom / cm ^3, it is necessary to obtain a concentration at least higher than that in order to cause polytype conversion. However, if the concentration of the element to be doped is about 1 × 10 ²¹ atom / cm ^{3, the} probability of adverse effects such as polycrystal generation during crystal growth increases, so 1 × 10 ¹⁷ to 1 × 10 ²⁰ at
It can be said that doping in the range of om / cm ³ is appropriate. The doping gas introduction time is at least 10 in order to cause polytype conversion during crystal growth.
It is necessary to secure a sufficient time for forming a doping layer of a molecule (Si-C molecule) layer (0.0025 mm) or more. For this time, it is desirable to select an optimum value calculated from the crystal growth rate, the exhaust capacity of the growth apparatus and the like.

[0025]

EXAMPLE FIG. 5 shows an example of a production apparatus of the present invention, which is an apparatus for growing a SiC single crystal by the improved Rayleigh method using a seed crystal. First, the single crystal growth apparatus will be briefly described. Crystal growth is performed by subliming and recrystallizing the SiC powder raw material 2 as a raw material on the SiC single crystal 1 used as a seed crystal. Seed crystal SiC
Single crystal 1 is attached to the inner surface of graphite crucible lid 4 of graphite crucible 3. A raw material SiC powder raw material 2 is filled in a graphite crucible 3. Such a graphite crucible 3
Is installed inside the double quartz tube 5 by a graphite support rod 6. A graphite felt 7 for heat shield is installed around the graphite crucible 3. The double quartz tube 5
High vacuum exhaust (10 ^-3 Pa or less) by the vacuum exhaust device 11
In addition, the internal atmosphere can be pressure-controlled by Ar gas. Further, a work coil 8 is installed on the outer circumference of the double quartz tube 5, and the graphite crucible 3 can be heated by passing a high frequency current to heat the raw material and the seed crystal to a desired temperature. The temperature of the crucible is measured by using a dichroic thermometer by providing an optical path with a diameter of 2 to 4 mm in the center of the felt covering the upper and lower portions of the crucible and extracting light from the upper and lower portions of the crucible. The temperature of the lower part of the crucible is the raw material temperature, and the temperature of the upper part of the crucible is the seed temperature. In addition to Ar gas for controlling the internal atmosphere, various doping gases (nitrogen, trimethylaluminum, trimethylboron) are introduced into the gas pipe 9 to the manufacturing apparatus through the doping gas mass flow controller 10.

Next, an example of producing a SiC single crystal using this crystal growth apparatus will be described. First, as a seed crystal, an SiC single crystal wafer having a 6H polytype and a hexagonal system having a (000-1) C plane with 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. The inside of the graphite crucible 3 contains Si.
C powder raw material 2 was filled. Then, the graphite crucible 3 filled with the raw material is closed by a graphite crucible lid 4 having a seed crystal attached thereto, covered with a graphite felt 7, and then placed on a graphite support rod 6 to form a double quartz tube 5. Installed inside. After evacuating the inside of the quartz tube, an electric current was passed through the work coil to raise the raw material temperature to 2000 degrees Celsius. After that, Ar gas was introduced as an atmosphere gas at a flow rate of 140 sccm,
While maintaining the pressure inside the quartz tube at about 80 kPa, the raw material temperature was raised to the target temperature of 2400 degrees Celsius. The growth pressure was reduced to 1.3 kPa over about 30 minutes, and then the growth was continued for about 20 hours. At this time, the temperature gradient inside the crucible was 15 degrees Celsius / cm, and the growth rate was about 1 mm / hour.

When 1 hour had passed from the start of growth, nitrogen as a doping gas was introduced at a partial pressure of 554 Pa for 2 minutes. As a result, a nitrogen-doped layer (nitrogen concentration: 3 × 10 ¹⁹ atom / cm ³ ) was formed on the growth surface to a thickness of about 33 μm. Thereafter, the introduction of nitrogen gas was stopped to form an undoped layer (nitrogen concentration: 1 × 10 ¹⁷ atom / cm ³ ) and an interface between the underlying nitrogen-doped layer and the undoped layer was formed.

The subsequent growth was maintained under the undoped condition until the end of the growth. The obtained crystal has a diameter of 51 mm,
The height was about 20 mm.

The SiC single crystal thus obtained was analyzed by X-ray diffraction and Raman scattering.
It was found that a 4H polytype SiC single crystal different from the polytype was generated. Further, for the purpose of investigating the effect of this experiment, the grown single crystal ingot was cut and polished in a form vertical to the growth direction to form {00
A wafer having a plane perpendicular to the 01 plane was taken out. When the doped portion was observed with a microscope, it was confirmed that conversion from 6H polytype to 4H polytype occurred near the portion where nitrogen doping was stopped.

[0030]

As described above, according to the present invention, an improved sublimation recrystallization method using a seed crystal (Rayleigh method)
In, in the crystal growth, an interface between a doped layer containing a different element and an undoped layer not containing it is formed on the growth surface to introduce strain into the crystal structure and induce a crystal structure change. A high-quality SiC single crystal having a polytype different from that of the crystal) can be grown with good reproducibility. Further, since it is possible to arbitrarily convert between a plurality of polytypes, a high quality wafer of a plurality of different polytypes can be obtained from a single high quality seed crystal, which is an extremely excellent method for productivity.

By using such a SiC single crystal wafer, a high voltage / environment resistant electronic device having excellent electrical characteristics and a blue light emitting element having excellent optical characteristics can be manufactured.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of an improved sublimation recrystallization method.

FIG. 2 shows a schematic diagram of the crystal unit structure of both 4H and 6H polytypes, which are representative polytypes.

FIG. 3 is a diagram showing a change in crystal structure due to doping with aluminum atoms during growth of a SiC single crystal.

FIG. 4 is a diagram showing a change in crystal structure in the case of switching from doping of nitrogen atoms to undoping during growth of a SiC single crystal.

FIG. 5 is a configuration diagram showing an example of a single crystal growth apparatus used in the manufacturing method of the present invention.

[Explanation of symbols]

1 seed crystal (SiC single crystal) 2 SiC powder raw material 3 Graphite crucible 4 Graphite crucible lid 5 Double quartz tube 6 Graphite support rod 7 Graphite felt 8 work coil 9 gas piping 10 Doping gas mass flow controller 11 Vacuum exhaust device

Continued front page    (72) Inventor Tatsuo Fujimoto             20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel shares             Company Technology Development Division (72) Inventor Hirokatsu Yashiro             20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel shares             Company Technology Development Division F term (reference) 4G077 AA02 AB01 BE08 DA18 DB12                       EB01 SA01 SA06                 5F041 CA33 CA47 CA48 CA58

Claims (8)

[Claims] 1. A silicon carbide single crystal ingot having at least one layer containing a different element in the silicon carbide single crystal ingot. 2. The silicon carbide single crystal ingot according to claim 1, wherein the different element contained in the different element containing layer is nitrogen, boron, aluminum, or nitrogen and boron. 3. The content of the different element in the different element containing layer is 1 × 10 ¹⁷ to 1 × 10 ²⁰ atom / cm ³ .
The silicon carbide single crystal ingot according to claim 1 or 2. 4. The silicon carbide single crystal ingot according to claim 1, wherein the silicon carbide single crystals adjacent to each other with the different element-containing layer having different polytypes. 5. A caliber having a diameter of 50 mm or more.
The silicon carbide single crystal ingot according to any one of items 1 to 4. 6. A silicon carbide single crystal substrate obtained by cutting and polishing the silicon carbide single crystal ingot according to any one of claims 1 to 5. 7. A silicon carbide epitaxial wafer obtained by epitaxially growing the silicon carbide single crystal substrate according to claim 6. 8. The method for producing a silicon carbide single crystal ingot according to claim 1, further comprising the step of heating the raw material silicon carbide to grow a single crystal on a seed crystal by a sublimation recrystallization method. A method for producing a silicon carbide single crystal ingot, characterized in that a heterogeneous element other than a crystal constituent element is introduced during a single crystal growth for a predetermined period of crystal growth to form at least one heterogeneous element-containing layer. Method.