摘要 |
A method of forming an SiC crystal including placing a seed crystal of SiC in an insulated graphite container; placing a source of Si and C atoms in the insulated graphite container, where the source of Si and C atoms is for transport to the seed crystal to grow the SiC crystal; placing the container into the furnace; heating a furnace to a temperature from about 2,000° C. to about 2,500° C.; evacuating the furnace to a pressure from about 0.1 Torr and about 100 Torr; filling the furnace with an inert gas; and introducing dopant gas into the furnace with a controlled flow so as to form a plurality of stratified layers wherein each layer has dopant concentration different from a layer directly below and a layer directly above it. A 4H-SiC crystal made by the method. A 4H-SiC substrate cut from the SiC crystal made from the method. |