Recent layer-by-layer migration enhanced epitaxy growth of high quality GaAs(100) films at low temperatures suggested that smooth missing-dimer-free monolayer As- and Ga-terminated surfaces are attainable during the growth process or the grown films will contain a high concentration of antisite defects. Using the local-orbital density-functional molecular-dynamics method, we find that the smooth monolayer As-terminated surface may be the (2×4) surface with a three-dimer unit and a shifted dimer. The smooth monolayer Ga-terminated surface may be the (1×2) dimerized surface. © 1996 The American Physical Society.

• Received 23 May 1996

DOI:https://doi.org/10.1103/PhysRevB.54.7637