Structural characterization of double stacking faults induced by cantilever bending in nitrogen-doped 4H-SiC

Defects in highly nitrogen-doped 4H-SiC deformed by cantilever bending at 550 degrees C have been identified by weak-beam and high-resolution transmission electron microscopy techniques. The induced-defects consist of double stacking faults (DSFs) whose expansion produces a local 4H --> 3C phase transformation. Each DSF is bound by two identical 30 degrees Si(g) partial dislocations which glide on two adjacent basal planes. The DSFs belong to three different populations which differ by their extension as a function of the applied-stress and the 30 degrees Si( g) characteristics ( line direction L, Burgers vector b, glide planes and glide direction). The external mechanical stresses are the main driving forces involved in the DSF expansion. However, extra driving forces such as thermodynamic or electronic forces are also likely to be involved.