Interplay between segregation, roughness, and local strains in the growth of Ga0.75In0.25P alloy

In this work, using reflexion high energy electron diffraction and atomic f orce microscopy, we compare the growth of strained Ga0.75In0.25P alloys on GaAs(001) and GaP (001) substrates. We show that although the absolute stra in value is similar in both cases, the transition from a bidimensional to a three-dimensional growth mode occurs much faster in the tensile case than in the compressive one. We interpret this result with a microscopic theoret ical model which takes into account the interplay between a weak surface ro ughness, In vertical and lateral segregation, and strain effects. (C) 2000 American Institute of Physics. [S0003-6951(00)00828-7].