HREM study of stacking faults in GaN layers grown over sapphire substrate

摘要

Epitaxial GaN layers grown on sapphire contain a very large density of defects (threading dislocations, stacking faults, inversion domain boundaries....). Among these defects, we have performed the analysis of the basal stacking faults by high resolution transmission electron microscopy. Two faults, I-1 and I-2, were identified. The formation of the I-1 fault is based on the climb-dissociation process of the 1/3(11-20) or of the [0001] perfect dislocations whereas the I fault is due to the shear of the structure leading to a partial dislocation loop. [References: 14]