Morphology of basal plane dislocations in 4H-SiC homoepitaxial layers grown by chemical vapor deposition

The morphology of basal plane dislocations (BPDs) in 4H-SiC homoepitaxial layers has been investigated by plan-view transmission x-ray topography and molten KOH etching. Three types of BPDs are distinguished based on their morphologies. These include interfacial dislocations, curved dislocations, and circular loop dislocations around micropipes. Their characteristics are studied in detail and possible sources of their formation during epitaxy are discussed.