Interface Formation Between Co With S-Passivated Gaas(100)

Interface formation between Co and the sulfur-passivated GaAs(100) (by CH3CSNH2 treatment) has been studied by synchrotron radiation photoemission spectroscopy. Interface reaction is weak, a stable interface forms at the coverage of 0.8 nm. Ga atoms bonded with S at the surface exchange with Co atoms and cause the formation of Co-S bonding, no segregated As appears at the surface of Co overlayer, in contrast with the case of Co/GaAs(100). This indicates that S-passivation on GaAs(100) is an effective way of inhibiting the interdiffusiion of As and Ga through the coverage.