The formation of super-dislocation/micropipe complexes in 6H-SiC

Atomic force microscope images of surface/micropipe intersections on the (0001) growth surface of a 6H-SiC single crystal grown by the physical vapor transport method indicate that micropipes are associated with superdislocations and that micron-scale deposits of a heterogeneous phase are frequently found in the vicinity of the defect. Based on our observations, we propose a model for the formation of superdislocation/micropipe complexes that involves the coalescence of unit screw dislocations. The unit dislocations are forced together as large steps grow around heterogeneous material on the surface. (Author)