A device for preparing single crystal and method for preparing silicon carbide single crystal

Abstract

The invention discloses a device for preparing a single crystal and a preparation method for a silicon carbide single crystal, belonging to the field of semiconductor materials. The device for preparing the single crystal comprises a crucible, a heating coil group and a heat preservation structure, wherein the crucible forms a growth cavity which comprises a raw material area used for placing rawmaterials and a crystal growth area used for arranging seed crystals; the heating coil group is arranged around the side wall of the crucible and comprises a first coil group corresponding to the rawmaterial area and a second coil group corresponding to the crystal growth area; and the inner diameter of the second coil group is increased in a direction from raw materials to seed crystals. The single crystal growth device provided by the invention can adjust the radial temperature gradient in the growth cavity for growth of the single crystal, can reduce the radial temperature gradient, can guarantee a certain axial temperature gradient at the same time, and can realize high-efficiency preparation of high-quality single crystals.

Description

technical field [0001] The application relates to a device for preparing a single crystal and a method for preparing a silicon carbide single crystal, 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 simultaneo...

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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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