Misfit dislocations at the GaN/SiC interface and their interaction with point defects

Films of n-GaN directly deposited on n-SiC by hydride vapor phase epitaxy w ere studied by means of electron beam induced current (EBIC) and microcatho doluminescence (MCL) measurements. These measurements reveal the presence o f a regular pattern of dark line defects in EBIC images and bright line def ects in MCL images. The defects are associated with misfit dislocations at the GaN/SiC interface. The density of defects network revealed by MCL is ve ry much lower than the density of defects in the EBIC images because in the former case only the portion of dislocations near which the stress has bee n relieved are detected. Deuterium implantation leads to complete eliminati on of the contrast due to misfit dislocations, to strong suppression of the bandedge recombination and to enhancement of the yellow luminescence band. (C) 2000 Elsevier Science Ltd. All rights reserved.