ATOMIC-FORCE MICROSCOPE OBSERVATION OF THE INITIAL-STAGE OF INAS GROWTH ON GAAS SUBSTRATES

The initial stage of InAs growth on GaAs(001) substrates has been inve stigated by atomic force microscopy. Three-dimensional (3D) islands of a uniformly small size and high density were observed at the initial stage not only for low substrate temperature (T-s) but also for low V/ III ratio. This is explained by a simple model based on the difference in the growth rate between strained and relaxed InAs surfaces. The 3D islands are found to agglomerate after the growth is interrupted unde r As pressure. We suppress the agglomeration and obtain an atomically flat InAs surface.