Growth Temperature Dependence of InAs Islands Grown on GaAs (001) Substrates

STM in conjunction with MBE has been used to investigate InAs islands and wetting layers on GaAs(001) substrates. STM results reveal that the size, density and shape of InAs islands depend on the growth temperature of InAs. With increasing growth temperature, island density decreases, size increases, and the shape becomes round rather than elliptical. In the photoluminescence (PL) results, a PL peak shift is observed with increasing InAs growth temperature. This shift agrees with the STM observation that larger islands are grown at higher growth temperatures. The change in the size and density of islands can be explained in terms of a critical nucleus in heterogeneous nucleation. Results indicate that controlling the growth temperature makes it possible to control the size, density and shape of InAs islands. 16 refs.