Patent ID: 9368345
Filing Date: 2016-06-14
CPC Classification: C23C,H01L

Claim Text:
1. A method of manufacturing a silicon carbide semiconductor substrate, comprising steps of: preparing a silicon carbide substrate; forming a first silicon carbide semiconductor layer on said silicon carbide substrate using a first source material gas; and forming a second silicon carbide semiconductor layer on said first silicon carbide semiconductor layer using a second source material gas, in said step of forming a first silicon carbide semiconductor layer and said step of forming a second silicon carbide semiconductor layer, ammonia gas being used as a dopant gas, said first source material gas having a C/Si ratio of not less than 1.6 and not more than 2.2, said C/Si ratio being the number of carbon atoms to the number of silicon atoms, an impurity concentration in said first silicon carbide semiconductor layer is higher than an impurity concentration in said second silicon carbide semiconductor layer.