Effects of AlGaN/AlN Stacked Interlayers on GaN Growth on Si (111)

Abstract

We report the growth of high quality and crack-free GaN film on Si (111) substrate using Al0.2Ga0.8N/AlN stacked interlayers. Compared with the previously used single A1N interlayer, the AlGaN/AlN stacked interlayers can more effectively reduce the tensile stress inside the GaN layer. The cross-sectional TEM image reveals the bending and annihilation of threading dislocations (TDs) in the overgrown GaN film which leads to a decrease of TD density.