HVPE-GaN: comparison of emission properties and microstructure of films grown on different laterally overgrown templates

We report on a comparative study of defect and emission distributions in thick hydride vapor phase epitaxial (HVPE) GaN films grown on two different patterned template structures separately produced by multi-step procedures using metalorganic vapor phase epitaxy (MOVPE). The observed differences in the microstructures and emission distributions at the early stages of the growth in both cases were related to the change of the dominating growth mode sequence and point defects incorporation. Both template structures were found to favor formation of voids in the coalescence regions, which leads to a partial strain relaxation and allows overgrowth of thicker films without cracks.