Studies of interface formation between Co with GaAs(100) and S-passivated GaAs(100)

Abstract

Abstract Interface formation between Co with GaAs(100) and S-passivated GaAs(100) by CH 3 CSNH 2 treatment has been studied with synchrotron radiation photoemission. Strong interface disruption and reaction occurs between the overlayer with GaAs(100) even at low Co coverage (∼0.2 nm), while the reaction is much weaker on S/GaAs(100); a stable interface forms at a coverage of 1 nm and 0.8 nm, respectively. For S-passivated GaAs(100), Ga atoms bonded with S at the surface exchange with Co atoms and cause the formation of Co–S bonding, the amount of As bonded with Co is much less than that on GaAs(100), no segregated As appears at the surface of Co overlayer, in contrast with the case of Co/GaAs(100), indicating that S-passivation on GaAs(100) is an effective way of inhibiting the interdiffusion of As and Ga through the overlayer.