Polar surface dependence of epitaxy processes: ZnSe on GaAs{111}A, B-(2×2)

Thin films of ZnSe are heteroepitaxially grown on GaAs{111}A, B-(2×2) surfaces. On the GaAs(111)A-(2×2) surface ZnSe grows in a biatomic layer-by-layer mode. Interestingly, at the very initial stage of ZnSe growth on GaAs(111)A, the growth rate increases and decreases with increasing Se to Zn flux ratio and ZnSe film thickness, respectively. On the other hand, ZnSe growth on GaAs(111)B-(2×2) proceeds in an island mode regardless of the flux ratio. A possible mechanism for the onset of such different growth modes is discussed.