². The rotation time after starting the rotation of the graphite lifting rod in forward and reverse directions was 5 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 150 r/min, and the total time for the acceleration and deceleration was 10 min, and the cycle was repeated until the end of growth. The graphite crucible was rotated in forward and reverse directions at a speed of 0 r/min, with a rotational acceleration of ±0 r/min², until the end of growth. The graphite lifting rod was lifted upward at a speed of 100 μm/h. After growth for 80 h, the graphite lifting rod adhered with the seed crystals was lifted upward at a speed of 10 mm/h so as to completely disconnect the grown crystals from the liquid level of the flux, and the heating was stopped. Then, the temperature of the grown crystals and the graphite crucible was slowly lowered. After the temperature drops to room temperature, the chamber of the high-temperature growth furnace was opened and the grown crystals were taken out. Since the SiC single crystals of this example involved doping of Al and N, the 4-inch semi-insulating 3C-SiC single crystals of the present invention were obtained.

Example 3

A 6-inch n-type 4H-SiC seed crystal single crystal substrate with a deflection angle of 8° was fixed to a graphite seed crystal holder with a thickness of 10 mm, and then the graphite seed crystal holder was fixed on a graphite lifting rod. The Si-side was used as the growth surface. Si:Co:Y:Al elementary substance particles with a molar ratio of 30:60:5:5 were mixed homogeneously and placed in a graphite crucible and compacted. The graphite crucible had an inner diameter of 200 mm, a height of 150 mm and a wall thickness of 20 mm, and the inner wall of the graphite crucible used was dense plane and the bottom of the graphite crucible was dense plane. The graphite crucible and the graphite lifting rod were loaded into a high-temperature growth furnace, the furnace chamber of the high-temperature growth furnace was closed, and the furnace chamber was vacuumized to below 10⁻⁵Pa by using a mechanical pump and a molecular pump, and helium and nitrogen with a gas volume ratio of 95:5 were introduced therein until the pressure inside the high-temperature growth furnace reached 0.2 atm. Then the gas valves were closed and the gas filling was stopped. The graphite crucible was heated to control the temperature during the growth of 3C-SiC single crystals so that the temperature at the SiC seed crystals during the growth of single crystals was 1900° C. The graphite lifting rod was pushed down to make it contact with the molten flux and start the growth of 3C-SiC single crystals. During the growth, the temperature gradient of the melt was 10° C./cm. The graphite lifting rod fixed with the SiC seed crystals was rotated in forward and reverse directions at a speed of 20 r/min, with a rotational acceleration of ±5 r/min². The rotation time after starting the rotation of the graphite lifting rod in forward and reverse directions was 5 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 20 r/min, and the total time for the acceleration and deceleration was 1 min, and the cycle was repeated until the end of growth. The graphite crucible was rotated in forward and reverse directions at a speed of 5 r/min, with a rotational acceleration of ±5 r/min². The rotation time after starting the rotation of the graphite crucible in forward and reverse directions was 5 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 5 r/min, and the total time for the acceleration and deceleration was 1 min, and the cycle was repeated until the end of growth. The graphite lifting rod was lifted upward at a speed of 100 μm/h. After growth for 120 h, the graphite lifting rod was lifted upward at a speed of 30 mm/h so as to completely disconnect the grown crystal from the liquid level of the flux melt, and the heating was stopped. Then, the temperature of the grown crystals and the graphite crucible was slowly lowered. After the temperature drops to room temperature, the chamber of the high-temperature growth furnace was opened and the grown crystals were taken out.

FIG. 4 shows the Raman spectrum of the p-type 3C-SiC single crystals grown in this example. FIG. 4 illustrates that the wafers grown are all 3C-SiC single crystals without any other crystal forms.

Example 4

A 2-inch n-type 3C-SiC single crystal seed crystal substrate with a deflection angle of 0° was fixed to a graphite seed crystal holder with a thickness of 20 mm, and then the graphite seed crystal holder was fixed on a graphite lifting rod. The Si-side was used as the growth surface. Si:Ni:Ce:Ga:Al elementary substance particles with a molar ratio of 40:30:15:14.9:0.1 were mixed homogeneously and placed in a graphite crucible and compacted. The graphite crucible had an inner diameter of 100 mm, a height of 150 mm and a wall thickness of 20 mm, and the inner wall of the graphite crucible used was honeycombed and the bottom of the graphite crucible was plane. The graphite crucible and the graphite lifting rod were loaded into a high-temperature growth furnace, the furnace chamber of the high-temperature growth furnace was closed, and the furnace chamber was vacuumized to below 10⁻³Pa by using a mechanical pump and a molecular pump, and helium and nitrogen with a gas volume ratio of 85:15 were introduced therein until the pressure inside the high-temperature growth furnace reached 0.2 atm. Then the gas valves were closed and the gas filling was stopped. The graphite crucible was heated to control the temperature during the growth of 3C-SiC single crystals so that the temperature at the SiC seed crystals during the growth of single crystals was 1900° C. The graphite lifting rod was pushed down to make contact with the molten flux and start the growth of 3C-SiC single crystals. During the growth, the temperature gradient of the melt was 10° C./cm. The graphite lifting rod fixed with the SiC seed crystals was rotated in forward and reverse directions at a speed of 200 r/min, with a rotational acceleration of ±30 r/min². The rotation time after starting the rotation of the graphite lifting rod in forward and reverse directions was 20 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 200 r/min, and the total time for the acceleration and deceleration was 20 min, and the cycle was repeated until the end of growth. The graphite crucible was rotated in forward and reverse directions at a speed of 20 r/min, with a rotational acceleration of ±30 r/min². The rotation time after starting the rotation of the graphite crucible in forward and reverse directions was 5 min, and then it was slowly decelerated to 0 rpm and then accelerated in the reverse direction to 20 r/min, and the total time for the acceleration and deceleration was 10 min, and the cycle was repeated until the end of growth. The graphite lifting rod was lifted upward at a speed of 60 μm/h. After growth for 60 h, the graphite lifting rod was lifted upward at a speed of 10 mm/h so as to completely disconnect the grown crystal from the liquid level of the flux melt, and the heating was stopped. Then, the temperature of the grown crystals and the graphite crucible was slowly lowered. After the temperature drops to room temperature, the chamber of the high-temperature growth furnace was opened and the grown crystals were taken out.

FIG. 5 shows HRTEM and SAED spectra of the n-type 3C-SiC single crystals grown in this example. FIG. 5 further confirms that the grown SiC single crystals are 3C-SiC single crystals.

Example 5

A 2-inch p-type 3CSiC single crystal wafer with a deflection angle of 0° was fixed to a graphite seed crystal holder with a thickness of 30 mm, and then the graphite seed crystal holder was fixed on a graphite lifting rod. The Si-side was used as the growth surface. Si:Ni:Ce:Ga:Al elementary substance particles with a molar ratio of 40:40:10:2:8 were mixed homogeneously and placed in a graphite crucible and compacted. The graphite crucible had an inner diameter of 100 mm, a height of 150 mm and a wall thickness of 10 mm, and the inner wall of the graphite crucible used was zigzag. The graphite crucible and the graphite lifting rod were loaded into a high-temperature growth furnace, the furnace chamber of the high-temperature growth furnace was closed, and the furnace chamber was vacuumized to below 10⁻³Pa by using a mechanical pump and a molecular pump, and argon and nitrogen with a gas volume ratio of 95:5 were introduced therein until the pressure inside the high-temperature growth furnace reached 1 atm. The gas valves were closed and the gas filling was stopped. The graphite crucible was heated to control the temperature during the growth of 3C-SiC single crystals so that the temperature at the SiC seed crystals during the growth of single crystals was 1900° C. The graphite lifting rod was pushed down to make it contact with the molten flux and start the growth of 3C-SiC single crystals. During the growth, the temperature gradient of the melt was 10° C./cm. The graphite lifting rod fixed with the SiC seed crystals was rotated in forward and reverse directions at a speed of 150 r/min, with a rotational acceleration of ±30 r/min². The rotation time after starting the rotation of the graphite lifting rod in forward and reverse directions was 60 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 150 r/min, and the total time for the acceleration and deceleration was 30 min, and the cycle was repeated until the end of growth. The graphite crucible was rotated in forward and reverse directions at a speed of 50 r/min, with a rotational acceleration of ±30 r/min². The rotation time after starting the rotation of the graphite crucible in forward and reverse directions was 60 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 50 r/min, and the total time for the acceleration and deceleration was 30 min, and the cycle was repeated until the end of growth. The graphite lifting rod was lifted upward at a speed of 60 μm/h. After growth for 60 h, the graphite lifting rod was lifted upward at a speed of 10 mm/h so as to completely disconnect the grown crystal from the liquid level of the flux melt, and the heating was stopped. Then, the temperature of the grown crystals and the graphite crucible was slowly lowered. After the temperature drops to room temperature, the chamber of the high-temperature growth furnace was opened and the grown crystals were taken out. The present invention can grow 2-inch p-type 3C-SiC single crystal crystals.

Example 6

A 6-inch n-SiC single crystal wafer with a deflection angle of 4° was fixed to a graphite seed crystal holder with a thickness of 40 mm, and then the graphite seed crystal holder was fixed on a graphite lifting rod. The Si-side was used as the growth surface. Si:Ni:Ce:Al elementary substance particles with a molar ratio of 40:40:10:10 were mixed homogeneously and placed in a graphite crucible and compacted. The graphite crucible had an inner diameter of 200 mm, a height of 200 mm and a wall thickness of 30 mm, and the side wall of the graphite crucible used was processed to be zigzag and the inner bottom surface of the crucible was processed to be porous. The graphite crucible and the graphite lifting rod were loaded into a high-temperature growth furnace, the furnace chamber of the high-temperature growth furnace was closed, and the furnace chamber was vacuumized to below 10⁻³Pa by using a mechanical pump and a molecular pump, and argon and nitrogen with a gas volume ratio of 70:30 were introduced therein until the pressure inside the high-temperature growth furnace reached 0.8 atm. The gas valves were closed and the gas filling was stopped. The graphite crucible was heated to control the temperature during the growth of 3C-SiC single crystals so that the temperature at the SiC seed crystals during the growth of single crystals was 1900° C. The graphite lifting rod was pushed down to make it contact with the molten flux and start the growth of 3C-SiC single crystals. During the growth, the temperature gradient of the melt was 10° C./cm. The graphite lifting rod fixed with the SiC seed crystals was rotated in forward and reverse directions at a speed of 200 r/min, with a rotational acceleration of ±12 r/min². The rotation time after starting the rotation of the graphite lifting rod in forward and reverse directions was 180 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 200 r/min, and the total time for the acceleration and deceleration was 60 min, and the cycle was repeated until the end of growth. The graphite crucible was rotated in forward and reverse directions at a speed of 100 r/min, with a rotational acceleration of ±12 r/min². The rotation time after starting the rotation of the graphite crucible in forward and reverse directions was 180 min, and then it was slowly decelerated to 0 rpm and then accelerated in the opposite direction to 200 r/min, and the total time for the acceleration and deceleration was 60 min, and the cycle was repeated until the end of growth. The graphite lifting rod was lifted upward at a speed of 60 μm/h. After growth for 80 h, the graphite lifting rod was lifted upward at a speed of 10 mm/h so as to completely disconnect the grown crystal from the liquid level of the flux melt, and the heating was stopped. Then, the temperature of the grown crystals and the graphite crucible was slowly lowered. After the temperature drops to room temperature, the chamber of the high-temperature growth furnace was opened and the grown crystals were taken out.

FIG. 6 shows (a) AFM spectrum and (b) step height distribution diagram of the n-type 3C-SiC single crystals grown in this example. FIG. 6 illustrates the growth of 3C-SiC single crystals in a step-flow manner, with the height of the step-flow ranging from 15 to 35 nm.

Example 7

A 4-inch n-type 3C-SiC single crystal wafer with a deflection angle of 0° was fixed to a graphite seed crystal holder with a thickness of 10 mm, and then the graphite seed crystal holder was fixed on a graphite lifting rod. The C-side was used as the growth surface. Si:Ti:Ce:Al elementary substance particles with a molar ratio of 50:40:9.99:0.01 were mixed homogeneously and placed in a graphite crucible and compacted. The graphite crucible had an inner diameter of 150 mm, a height of 200 mm and a wall thickness of 10 mm, and the side wall of the graphite crucible used was processed to be zigzag and the inner bottom surface of the graphite crucible was processed to be porous. The graphite crucible and the graphite lifting rod were loaded into a high-temperature growth furnace, the furnace chamber of the high-temperature growth furnace was closed, and the furnace chamber was vacuumized to below 10⁻³Pa by using a mechanical pump and a molecular pump, and argon and nitrogen with a gas volume ratio of 80:20 were introduced therein until the pressure inside the high-temperature growth furnace reached 0.8 atm. The gas valves were closed and the gas filling was stopped. The graphite crucible was heated to control the temperature during the growth of 3C-SiC single crystals so that the temperature at the SiC seed crystals during the growth of single crystals was 1900° C. The graphite lifting rod was pushed down to make it contact with the molten flux and start the growth of 3C-SiC single crystals. During the growth, the temperature gradient of the melt was 10° C./cm. The graphite lifting rod fixed with the SiC seed crystals was rotated in forward and reverse directions at a speed of 5 r/min, with a rotational acceleration of ±5 r/min