Photoemission study of the metal deposition on the (NH4)2Sx-treated GaAs(100) surface at room temperature

Abstract

Abstract We have used synchrotron radiation photoemission spectroscopy to investigate the chemical interactions and atomic intermixing at metal/GaAs interfaces during deposition of Au and In onto GaAs(100) surfaces that are chemically treated in (NH 4 ) 2 S x and in H 2 SO 4 . For the Au deposition onto the (NH 4 ) 2 S x -treated surface, alloy formation and metal segregation at interfacial regions are significantly suppressed as compared to the Au deposition onto the H 2 SO 4 -treated surface. On the other hand, for In deposition, the In adatoms strongly interact with the (NH 4 ) 2 S x -treated surface to generate a thin layer of In x Ga 1− x As alloy on which the In overlayer is formed in a layer-by-layer fashion. We found that Au reacts with the H 2 SO 4 -treated surface to generate AuGa alloy, but In does not interact appreciably with the surface, leading to the island growth of the In overlayer.