The interference pattern around micro-pipes of 6H-SiC single crystal (001) substrate was characterized by polarizing optical microscopy. The interference pattern showed anisotropy around micro-pipes, which was thought to result from edge dislocation caused by internal strain. A model experiment using a stress-induced acryl resin board certainly demonstrated a similar interference pattern to the 6H-SiC single crystal, when tensile and compression stresses were applied to each side in the vicinity of an open hole in the acryl resin board. Stress distributions around the micro-pipes of 6H-SiC single crystals were considered with regard to the existence of edge and screw dislocations. The size of the micro-pipe depended on the Burgers vector, and an internal strain generated around the micro-pipe was correlated with the edge dislocation.

Screw and Edge Dislocations-Induced Internal Strain around Micropipes of 6H-SiC Single Crystals. H.Ohsato, T.Kato, T.Okuda: Materials Science in Semiconductor Processing, 2001, 4[6], 483-7