High-quality n-type silicon carbide and preparation method thereof

Abstract

The invention discloses a preparation method of a high-quality n-type silicon carbide crystal. The preparation method comprises the following steps: (1) assembling; (2) heating; and (3) growing the crystal: introducing a mixed gas containing a nitrogen source gas and an inert protective gas into a crystal growth furnace, controlling the crystal growth furnace to a required pressure, and growing the n-type silicon carbide crystal on a seed crystal, wherein the volume fraction of the nitrogen source gas in the mixed gas is gradually increased along with the downward movement of the long crystalsurface of the n-type silicon carbide crystal. According to the preparation method, the volume fraction of the nitrogen source gas is continuously regulated in the crystal growth process, and the partial pressure of the nitrogen source gas is gradually increased, so that the problem that the temperature rise of the crystal growth surface in the crystal growth process is not beneficial to nitrogendoping can be offset, and the problem that the crystal resistivity is unqualified and non-uniform due to reduction of the high-temperature nitrogen doping amount is effectively avoided; and the nitrogen doping amount in the crystal is optimized and regulated by gradually increasing the crystal growth pressure, so that the nitrogen doping uniformity and stability are effectively improved.

Description

technical field [0001] The application relates to a high-quality n-type silicon carbide crystal and a preparation method thereof, belonging to the technical field of semiconductor materials. Background technique [0002] As a third-generation semiconductor material, silicon carbide (SiC) is widely used in power electronics, optoelectronic devices and other fields because of its excellent properties such as large band gap, high saturation electron mobility, strong breakdown field, and high thermal conductivity. . High-quality crystals are the cornerstone of the development of semiconductor and information industries, and their preparation level restricts the preparation and performance of downstream devices. [0003] At present, the physical vapor transport (PVT) method is the main method for growing silicon carbide crystals. The equipment used to grow silicon carbide crystals by the physical vapor transport method is simple, and the process is easy to control. Using the phy...

AI Technical Summary

Problems solved by technology

[0004] Although the physical vapor transport method has made great progress in growing SiC crystals in recent years, the growth of SiC crystals is a complicated process. Therefore, the stability of the physical vapor transport method still needs further research.

Images