Surface chemistry and growth mechanisms studies of homo epitaxial (1Â 0Â 0) GaAs by laser molecular beam epitaxy

► The deposition of GaAs epilayer using LMBE was achieved. ► Chemistry evolution of GaAs epilayer during deposition was investigated using in situ XPS. ► The growth process is heavily influenced by the surface chemistry and morphology of thermally desorbed GaAs substrate. ► It is found that a predominant step flow growth mode for the growth of GaAs by LMBE in this study. ► The incorporation of As species into GaAs epilayer is more efficient in LMBE than conventional MBE.