A method of growing high-quality silicon carbide crystals in an oxygen-containing atmosphere

Abstract

The invention discloses a method for growing high-quality silicon carbide crystals in an oxygen-containing atmosphere, which includes putting a graphite crucible equipped with silicon carbide raw materials and seed crystals into a SiC crystal growth furnace, and injecting oxygen-containing gases such as carbon dioxide or oxygen It is directly introduced into the graphite crucible through the pipeline to grow high-quality silicon carbide crystals. Compared with the conventional gas-phase transport method for growing silicon carbide crystals, the difference of the present invention is that oxygen-containing gases such as oxygen or carbon dioxide are introduced into the growth system, and the graphite suspended in the growth atmosphere is consumed by the oxygen-rich gas The fine particles can significantly reduce inclusion defects in the crystal, obtain high-quality silicon carbide crystals, and improve the yield of silicon carbide crystal growth.

Description

technical field

[0001] The invention relates to a method for growing high-quality silicon carbide crystals, which can significantly reduce the defects of silicon carbide crystal inclusions and improve the quality and yield of silicon carbide crystals, and relates to the field of SiC crystal growth. Background technique

[0002] "One generation of materials, one generation of devices". Following Si and GaAs, the third-generation semiconductor SiC materials and devices have become a research hotspot in the international semiconductor industry. With its unique characteristics such as large band gap, high critical breakdown electric field, high electron saturation drift velocity and high thermal conductivity, SiC material has become an ideal material for making high-power, high-temperature, high-voltage semiconductor devices. In power electronics technology, LED , Microwave communication and other fields have shown great application potential.

[0003] At present, the most eff...

Examples

Embodiment 1

[0036] A piece of 4H-SiC seed crystal with a diameter of 100 mm, and the C plane is selected as the crystal growth plane. The schematic diagram of the growth chamber structure is shown in figure 2 , The inner side of the graphite crucible and the inner side of the graphite pipe are coated with TaC coating. The temperature at the raw material is set at 2200-2300°C, and the temperature at the seed crystal is 150°C lower than that of the raw material. During the growth process, the flow rate of Ar was 60 sccm outside the growth chamber, and the mixed gas of oxygen and carbon dioxide was passed into the growth chamber through graphite pipes. The volume mixing ratio of oxygen and carbon dioxide was 1:1, and the flow rate of the mixed gas of oxygen and carbon dioxide was constant during the growth process 10 sccm, one 4H-SiC crystal was grown. Cut and process the crystal into a 4-inch SiC wafer with a thickness of 500 microns, and use an optical microscope to detect the number of...

Embodiment 2

[0039] One piece of 6H-SiC seed crystal with a diameter of 76.2mm, and the Si surface is selected as the crystal growth surface. The schematic diagram of the growth chamber structure is shown in image 3 As shown, the inner and outer sides of the graphite crucible and the inner and outer sides of the graphite pipe are coated with TaC coating. Put the above-mentioned SiC raw material, SiC seed crystal, and the crucible with graphite pipe into the growth furnace, set the temperature at the raw material at 2300-2400°C, and set the temperature at the seed crystal at 100°C lower than the raw material. During the growth process, high-purity argon gas is passed through the growth chamber, with a flow rate of 100 sccm; high-purity carbon dioxide gas is passed into the growth crucible through graphite pipes, and the gas flow rate of carbon dioxide increases linearly with the growth time during the growth process. At the end of the growth, it increased to 15 sccm, and one 6H-SiC crysta...

technical field

[0001] The invention relates to a method for growing high-quality silicon carbide crystals, which can significantly reduce the defects of silicon carbide crystal inclusions and improve the quality and yield of silicon carbide crystals, and relates to the field of SiC crystal growth. Background technique

[0002] "One generation of materials, one generation of devices". Following Si and GaAs, the third-generation semiconductor SiC materials and devices have become a research hotspot in the international semiconductor industry. With its unique characteristics such as large band gap, high critical breakdown electric field, high electron saturation drift velocity and high thermal conductivity, SiC material has become an ideal material for making high-power, high-temperature, high-voltage semiconductor devices. In power electronics technology, LED , Microwave communication and other fields have shown great application potential.

[0003] At present, the most eff...

Examples

Embodiment 1

[0036] A piece of 4H-SiC seed crystal with a diameter of 100 mm, and the C plane is selected as the crystal growth plane. The schematic diagram of the growth chamber structure is shown in figure 2 , The inner side of the graphite crucible and the inner side of the graphite pipe are coated with TaC coating. The temperature at the raw material is set at 2200-2300°C, and the temperature at the seed crystal is 150°C lower than that of the raw material. During the growth process, the flow rate of Ar was 60 sccm outside the growth chamber, and the mixed gas of oxygen and carbon dioxide was passed into the growth chamber through graphite pipes. The volume mixing ratio of oxygen and carbon dioxide was 1:1, and the flow rate of the mixed gas of oxygen and carbon dioxide was constant during the growth process 10 sccm, one 4H-SiC crystal was grown. Cut and process the crystal into a 4-inch SiC wafer with a thickness of 500 microns, and use an optical microscope to detect the number of...

Embodiment 2

[0039] One piece of 6H-SiC seed crystal with a diameter of 76.2mm, and the Si surface is selected as the crystal growth surface. The schematic diagram of the growth chamber structure is shown in image 3 As shown, the inner and outer sides of the graphite crucible and the inner and outer sides of the graphite pipe are coated with TaC coating. Put the above-mentioned SiC raw material, SiC seed crystal, and the crucible with graphite pipe into the growth furnace, set the temperature at the raw material at 2300-2400°C, and set the temperature at the seed crystal at 100°C lower than the raw material. During the growth process, high-purity argon gas is passed through the growth chamber, with a flow rate of 100 sccm; high-purity carbon dioxide gas is passed into the growth crucible through graphite pipes, and the gas flow rate of carbon dioxide increases linearly with the growth time during the growth process. At the end of the growth, it increased to 15 sccm, and one 6H-SiC crysta...

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