Evidence of perfect dislocation glide in nanoindented 4H-SiC

Abstract

Plastic deformation of a 4H-SiC wafer has been produced by nanoindentation at room temperature. The superficial layer of the specimen in the indented area has been lifted out thanks to a specific focussed ion beam micromachining method and the deformation microstructure close to the imprints has been investigated by means of both conventional and high-resolution transmission electron microscopy (TEM). The analysis of the images revealed the presence of various types of extended defects. Perfect dislocations and single stacking faults bounded by isolated Shockley partial dislocations have been observed on the basal plane. Perfect dislocations have also been evidenced out of the basal plane. These results highlight the competition between various activated systems involved during the plastic deformation of 4H-SiC in the brittle regime.