Cross-sectional observations of 6H-type basal planes revealed 2 forms of planar defect. One resembled a triangle, while the other resembled a thin rectangle with the long edge parallel to the interface. These defects were related to edge dislocations. Micropipes led to the creation of the planar defects, and the screw dislocations changed into edge dislocations. The micropipe consequently disappeared or shrank.

Polytype and Defect Control of Two Inch Diameter Bulk SiC M.Sasaki, H.Shiomi, H.Harima, S.Nishino: Materials Science Forum, 2000, 338-342, 485-8