SiC Epitaxial Growth by Vertical Hot-Wall Type Chemical Vapor Deposition.

Abstract

Epitaxial growth of silicon carbide (SiC) by “Vertical hot-wall type chemical vapor deposition (CVD)” has been investigated. Higher growth rates over 10μm/h has been realized at a growth temperature of 1700oC. The surface morphology has been observed by atomic force microscopy to examine formation of macroscopic steps. In addition to conventional (0001) face, 6H- and 4H-SiC epitaxial layers with smooth surfaces have been realized on (11-20) and (1-100) faces. Crystallographical quality of epitaxial layers has been evaluated by X-ray diffraction. Furthermore, we developed a novel doping method, “Pulse doping”, during epitaxial growth for a well-controlled doped layer. A pulse valve that could open and close within a very short period less than 10 μs was used in this study to supply the dopant gases. Carrier concentrations of the doped layers have been precisely controlled, and their abrupt doping profiles have been achieved.