Core Composition of Partial Dislocations in N-Doped 4H-SiC Determined by TEM Techniques, Dislocation Core Reconstruction and Image Contrast Analysis

摘要

Defects were created in N-doped 4H-SiC by cantilever bending from a scratch on the (1120) surface under compression. They consist of two stacking faults (double stacking faults) expanding from the scratch in [1100] or [1100] directions. The character and core composition of the leading Shockley partial dislocations were determined by coupling WB, LACBED, contrast analysis of (1120) HRTEM images and dislocation core reconstructions. Each double stacking fault is due to the glide of a pair of identical Si-core partial dislocations in two adjacent glide planes in which the Si-C dumbbells exhibit the same orientation. Such a feature as well as the asymmetrical expansion of the defects is related to lack of mobility of C-core partial dislocations in that range of temperatures (550 °C-700 °C).