Pendeoepitaxy of gallium nitride thin films

Pendeoepitaxy, a form of selective lateral growth of GaN thin films has bee n developed using GaN/AlN/6H-SiC(0001) substrates and produced by organomet allic vapor phase epitaxy. Selective lateral growth is forced to initiate f rom the (11(2) over bar 0) GaN sidewalls of etched GaN seed forms by incorp orating a silicon nitride seed mask and employing the SiC substrate as a ps eudomask. Coalescence over and between the seed forms was achieved. Transmi ssion electron microscopy revealed that all vertically threading defects st emming from the GaN/AlN and AlN/SiC interfaces are contained within the see d forms and a substantial reduction in the dislocation density of the later ally grown GaN. Atomic force microscopy analysis of the (11(2) over bar 0) face of discrete pendeoepitaxial structures revealed a root mean square rou ghness of 0.98 Angstrom. The pendeoepitaxial layer photoluminescence band e dge emission peak was observed to be 3.454 eV and is blueshifted by 12 meV as compared to the GaN seed layer. (C) 1999 American Institute of Physics. [S0003-6951(99)03128-9].