Metal–organic molecular beam epitaxy of GaAsNSe films using Ga droplets on GaP(001)

Abstract

GaAsNSe films were grown by metal–organic molecular beam epitaxy using Ga droplets prepared on GaP(001) substrates. Ga droplets were formed on Sb-terminated GaP surfaces at a low density of 5.3 × 108 cm−2 at a substrate temperature of 520 °C. The Ga droplets were ∼63 nm in height and ∼164 nm in diameter. At the initial growth of GaAsNSe on GaP, step-flow growth was promoted by the atomic diffusion from the Ga droplets and flat terraces spread over the surface. Although there was a large lattice mismatch of 3.5% between GaAsNSe and GaP, three-dimensional island growth and pit formation were reduced considerably by the surface diffusion of Ga. In this paper, we report the contribution of Ga droplets to the heterogrowth process of GaAsNSe/GaP.