Calculations of Equilibrium Critical Thickness for Non-Polar Wurtzite InGaN/GaN Systems

Abstract

We investigate critical thicknesses of InGaN epilayers grown on GaN substrates with the growth-plane not being the c-plane. In particular, we focus on non-polar orientations with growth planes being the m- and a-planes. We have taken into account the proper hexagonal symmetry of wurtzite GaN. We have found that there is only a small difference in the critical thickness for the cplane and the a-plane material; however, in the case of the m-plane material, we predict a quite different behaviour along the (in-plane) c-axis and the perpendicular (in-plane) a-direction.