A method of producing silicon carbide seed crystals by liquid phase epitaxy

Abstract

The present invention provides a method for producing silicon carbide seed crystals by liquid phase epitaxy, comprising the following steps: S1. Cutting a single crystal silicon carbide crystal of a certain thickness into a plurality of sub-crystal plates, and cutting the plurality of sub-crystal plates along the edges with C The surface is beveled at a fixed angle, and the carbon and silicon surfaces of the plurality of sub-crystal plates are ground and polished to ensure a consistent surface shape; S2, the sub-crystal plates are spliced ​​according to the target shape to obtain a splicing plate with a splicing gap, A first metal film is prepared on the silicon surface of the splice plate; S3, isostatically bonding the splice plate and the seed crystal tray to obtain a bonded crystal plate; S4, performing liquid phase epitaxy repair on the bonded crystal plate; S5, slicing processing to obtain a silicon carbide seed crystal. The method of the present invention obtains the daughter crystal plate by cutting the single crystal silicon carbide crystal, and after splicing and liquid phase epitaxy repair, it is cut into a plurality of wafers. Large-size SiC seed crystals with lower cost.

Description

technical field [0001] The invention belongs to the technical field of silicon carbide crystal growth, in particular to a method for producing silicon carbide seed crystals by liquid phase epitaxy. Background technique [0002] The third-generation semiconductor materials have gradually become the core support of the new generation of information technology. The mainstream products in the domestic silicon carbide single crystal substrate market have gradually shifted from 4-inch substrates to 6-inch substrates, and some companies in the world have 8-inch carbonized substrates. Mass production of silicon is on the agenda. At present, most domestic enterprises cannot obtain high-quality single wafers with a diameter of more than 200mm. As a seed crystal, it seriously affects the overall development progress of large-sized crystals. [0003] In order to solve this kind of situation, the current mainstream solution is to obtain large-size crystals. One is to use 4-inch or 6-inc...

AI Technical Summary

Problems solved by technology

There are many optimization schemes for liquid phase epitaxial growth, such as the schemes provided in patents CN106012021B and CN108977885A, but the fundamental problem of liquid phase growth is that the solubility of carbon in the melt is very low and the transport effect is not ideal. Patent CN110747504B provides a The growth method of silicon carbide single crystal uses rare earth and stirring to increase the solubility of graphite, but silicon carbide forms silicon carbide on the surface of graphite crucible, which further reduces the solubility of carbon, and does not solve the problem of crystal joint filling

Images