Dependence of generation and structures of stacking faults on growing surface stoichiometries in ZnSe/GaAs

Thin ZnSe films were grown by molecular beam epitaxy on Zn exposed (2×4) As-stabilized surfaces of GaAs epilayers under varied beam flux ratios. A very low density of faulted defects in the range of ∼ 104/cm2 was generated in samples grown under a condition with a mixture of both (2×1) and weak c(2×2) surface reconstructions at the initial stages of growth. However, an asymmetric distribution on the densities of extrinsic cation- and anion-terminated Shockley-type stacking faults were generated, respectively, in samples grown under Zn- and Se-rich surface stoichiometries.