A silicon carbide single crystal, substrate and preparation method thereof

Abstract

The application discloses a silicon carbide single crystal, a substrate and a preparation method thereof, belonging to the field of semiconductor materials. The silicon carbide single crystal preparation method comprises that the temperature measuring hole formed by the upper insulation layer group outside the crucible forms a low-temperature zone and a high-temperature zone in the crucible, and the raw material in the high-temperature zone is gas-phase transported to the surface of the seed crystal in the low-temperature zone by using a physical gas phase transport method. Carry out crystal growth; the upper insulation layer group includes the second insulation layer and the first insulation layer arranged in sequence along the direction of the raw material from the seed crystal, the first insulation layer is provided with the first opening, the second insulation layer is provided with the second opening, and the rotation adjustment mechanism Rotate the first insulation layer and / or the second insulation layer to adjust the cross-sectional area of ​​the temperature measuring hole formed by the first opening and the second opening, thereby adjusting the axial and radial temperature gradients in the crucible during the crystal growth process. The silicon carbide single crystal preparation method can not only adjust the radial temperature gradient in the growth chamber for growing single crystals; but also ensure a certain axial temperature gradient while reducing the radial temperature gradient, and produce high-quality silicon carbide single crystals with high efficiency. crystal.

Description

technical field [0001] The application relates to a silicon carbide single crystal, a substrate and a preparation method thereof, belonging to the field of semiconductor materials. Background technique [0002] Silicon carbide single crystal is one of the most important third-generation semiconductor materials. It is widely used in power electronics, RF devices, optoelectronic devices and other fields. [0003] At present, the main preparation method of silicon carbide single crystal is physical vapor transport (PVT) method. In the process of preparing single crystal by PVT method, there are radial temperature gradient and axial temperature gradient in the growth chamber of growing single crystal. In the stable growth stage of single crystal, a larger axial temperature gradient has a faster single crystal growth rate, and a smaller radial temperature gradient can reduce the introduction of stress and dislocation. However, it is difficult to simultaneously achieve a large ...

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Problems solved by technology

The existing induction coil heating method, on the one hand, is difficult to increase the axial temperature gradient of the growth chamber without affecting the radial temperature gradient and ensure a small radial temperature gradient; on the other hand, when reducing the radial temperature gradient , the axial temperature gradient also has a large drop, and the growth rate cannot be guaranteed

In addition, it is difficult to control the radial temperature gradient in a large range during the growth process of silicon carbide single crystal in the current equipment, and it is difficult to realize the change of radial temperature gradient required in the growth of silicon carbide single crystal

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