High-quality silicon carbide single crystal, and substrate and efficient preparation method thereof

Abstract

The invention discloses a high-quality silicon carbide single crystal, and a substrate and an efficient preparation method thereof, and belongs to the field of semiconductor materials. The preparationmethod comprises the following steps: putting raw materials and seed crystals into a crucible, assembling the crucible and a heat preservation structure into a crystal growth furnace, arranging a heating coil assembly at the periphery of the side wall of the crystal growth furnace, and mounting an adjusting mechanism; removing impurities; and growing the crystal, wherein the heating coil assemblycomprises a first coil assembly arranged corresponding to a raw material area and a second coil assembly arranged corresponding to a crystal growth area, and the inner diameter of the second coil assembly is increased in the direction from raw materials to seed crystals. The preparation method of the silicon carbide single crystal is characterized in that the axial temperature gradient in a growth cavity is formed, so the high-quality silicon carbide single crystal can be prepared; the radial temperature gradient in the growth cavity for growing the single crystal is adjusted, so the crystalgrowth rate and the crystal growth quality are improved; and the radial temperature gradient is reduced, and a certain axial temperature gradient can be ensured, so the high-quality silicon carbide single crystal can be efficiently prepared.

Description

technical field [0001] The application relates to a high-quality silicon carbide single crystal, a substrate and a high-efficiency 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 crystals by PVT method, there are radial temperature gradients and axial temperature gradients in the growth chamber where the crystals are grown. In the stable crystal growth stage, a larger axial temperature gradient has a faster crystal growth rate, and a smaller radial temperature gradient can reduce the introduction of stress and dislocation. However, it is difficult to simultaneously achie...

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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 also difficult to control the radial temperature gradient in a large range during the growth of silicon carbide crystals in the current equipment, and it is difficult to realize the change of the radial temperature gradient required in the growth of silicon carbide crystals.

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