Dislocation cores and hardness polarity of 4H-SiC

摘要

The hardness of opposite basal faces of 4H-DiC single crystals has been measured in the temperature range 25°- 1200 deg C. A strong hardness anisotropy between the silicon- terminated (001) and carbon-terminated (0001) faces of this polar crystal has been found. Transmission electron microscopy investigation of the dislocations in the plastic zone of the 1200 deg C indentations shows that they lie predom- inantly on the basal planes parallel to the indented face, and the extra-half planes of the nonscrew dislocations originate fro the indented face.