Growth and stacking fault reduction in semi-polar GaN films on planar Si(112) and Si(113)

We report on metal organic vapor phase epitaxy of semi‐polar growth of nearly (1$ \bar 1 $06) oriented GaN films on Si(112) and (1$ \bar 1 $05) and (1$ \bar 1 $04) GaN on Si(113). We analyze the GaN crystallites by field emission‐scanning electron microscopy (FE‐SEM), scanning transmission electron microscopy (STEM), photoluminescence (PL), and cathodoluminescence (CL). A correlation between optical properties and microstructure is presented. Our studies reveal a significant reduction of basal plane stacking faults (BSFs) in semi‐polar GaN grown on planar Si(112) by applying a low temperature (LT) AlN interlayer. We find that the insertion of the LT‐AlN interlayer can eliminate the stacking faults in the upper GaN layer, when the LT‐AlN interlayer is inserted on a smooth GaN buffer. The LT‐AlN interlayer results in lattice relaxation due to misfit dislocation formation at the GaN/LT–AlN interface. In comparison, GaN grown on Si(113) with same growth conditions and a rough GaN surface does not show any BSF reduction while it is reduced for a smooth GaN layer (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)