Anisotropic defect reduction in non-polar a-plane GaN grown by hydride vapor phase epitaxy on maskless patterned templates

Several non-polar a-plane GaN films had been grown by hydride vapor phase epitaxy (HVPE) on different designed metal organic chemical deposition (MOCVD) GaN templates, which exhibited various ridge-like sidewall facets surface morphologies. The templates induced a lateral growth at the early stage of the HVPE growth, and resulted in a kind of maskless epitaxy lateral overgrown (ELO) process. It is found that the dislocation reduced differently along 1 0 0 0] and ] directions in these HVPE a-plane GaN layers. In 0 0 0 1] direction, the dislocation reduction resulted from the optimal surface roughness value of the template. In ] direction, the inclined facet might be a main factor for the dislocation reduction in HVPE-GaN films. The maskless ELO process had a significant influence on decreasing the dislocation density.