CHARACTERIZATION OF INP ISLANDS ON INGAP/GAAS(001) - EFFECT OF DEPOSITION TEMPERATURE

Atomic force microscopy has been used to investigate the metalorganic chemical vapor deposition of InP on nominally flat InGdP/GaAs(001) substrates as a function of deposition temperature. In particular, the deposition time required for island formation as a function of deposition temperature is determined at a constant reactant flux, and the effect of InP deposition temperature on the island shape and size distributions is explored. The qualitative behavior of the growth changes very little with temperature, whereas the size and spatial distributions are significantly affected. In addition, the effect of InGaP surface morphology on the size and density of InP islands is compared at constant deposition times. From a detailed analysis of the islands on the various surfaces, the island density and base area are observed to be strong functions of surface morphology, while the height of the islands remains unchanged. These observations indicate that the size, uniformity, and density of the coherent islands are not dominated by strain energy, and, thus, they can be manipulated by changes in substrate morphology and growth conditions.