Defects in silicon carbide epilayers were examined by a growth (the first epilayer)–etch–regrowth (the second epilayer) process. The first SiC epilayer was mildly etched by molten KOH–NaOH eutectic to generate etch pit sizes of 2–12μm using a well-controlled process with good reproducibility, and then the second epilayer was grown on the etched epilayer. The evolution of defects from the first epilayer to the second epilayer was investigated. All of the individual basal plane dislocations in the first epilayer were converted to threading edge dislocations in the second epilayer, regardless of the etch pit size of the basal plane dislocations. The basal plane dislocations conversion could be accompanied by dislocation migration towards the up-step direction depending on the size of the etch pits. All of the in-grown stacking faults with triangular shape in the first epilayer were propagated into the second epilayer. The in-grown stacking faults were shown to be introduced only by the growth process. Due to the mild nature of eutectic etching, the etching process did not enhance the generation of any defects, especially stacking faults, or degrade the epilayer surface morphology. Since no new individual basal plane dislocations were generated in the second epilayer, a basal plane dislocation-free epilayer was achieved successfully with good surface morphology.

Investigations of Defect Evolution and Basal Plane Dislocation Elimination in CVD Epitaxial Growth of Silicon Carbide on Eutectic Etched Epilayers. H.Song, T.Rana, T.S.Sudarshan: Journal of Crystal Growth, 2011, 320[1], 95-102