Spheroid 3C inclusions in 8° off-axis 4H-SiC epilayers grown by chemical vapor deposition

Spheroidal inclusions in 4H-SiC homoepitaxial layers deposited by silane-based chemical vapor deposition (CVD) process have been investigated by KOH etching, optical microscopy, and transmission electron microscopy. The inclusions consist of polycrystalline 3C silicon carbide bearing no orientational relationship with the substrate and cause characteristic corrugation of epilayer surface referred to as “arrow” defect. Their origin is interpreted as due to SiC particles deposited on the wafer surface at the initial stages of the CVD process.