Selective area growth of GaN/AlN heterostructures

Abstract

Selective area growth of GaN stripes with a flat and smooth (0001) top plane has been achieved by optimizing MOCVD growth conditions. Strain of AlN/GaN heterostructures is reduced on selectively grown stripes even for a total AlN layer thickness of 200nm. Although AlN growth is observed on SiO2 masked areas, the selectivity of subsequent GaN layers is conserved. In comparison, cracks or macro-step formation appear for growth on wide stripes. Etch pit density of selectively grown GaN/AlN multi-layer structures seems to be greatly reduced to 1/1000 compared to the wide stripe growth.