SURFACE-REACTIONS OF GA AND AS ON SB-TERMINATED GAAS(001)

Surface reactions of As and Ga on Sb-terminated GaAs(001) were investigated by reflection high energy electron diffraction and photoelectron spectroscopy to examine the stability of an Sb terminating layer as a pseudomorphic GaSb layer formed on GaAs(001) for fabricating GaAs/GaSb/GaAs single quantum wells. In the As reaction, As atoms react with the Sb atoms and induce the breaking of Ga-Sb bonds. On the other hand, when Ga atoms are deposited, Ga atoms migrate on the Sb-terminated surface and the Sb layer is conserved even when the substrate is annealed until Sb atoms desorb. These features indicate that controlling As deposition on the Sb layer plays a key role in preventing intermixing between GaSb and a GaAs overlayer for fabricating the abrupt interface of GaAs/GaSb/GaAs single quantum well structures.