The observation of monolayer and bilayer growth during the deposition of GaAs(110) films by molecular beam epitaxy

Abstract

The growth of GaAs(110) films by molecular beam epitaxy (MBE) has been investigated in-situ using reflection high energy electron diffraction (RHEED). By careful choice of growth conditions, films with smooth surface morphology have been obtained and RHEED oscillations indicating two-dimensional growth by monolayer steps have been observed. At low growth temperatures and more arsenic rich conditions, RHEED oscillations with twice the period are observed, which suggests that under these conditions growth is occurring by the formation of islands with double layer steps. The dependence of the transition between the two growth modes on the growth conditions and arsenic flux suggests that reconstruction at step edges, which stabilises double layer steps at the lower temperature, may be responsible.