Physics and Chemistry during the Deposition and Oxidation of Ultrathin Mg Overlayer on GaAs(100) Surface

Full text: The interaction of active Mg metal with IIIA-VA compound semiconductor GaAs(100) as well as the oxidation of Mg ultrathin overlayer were studied by evaporating magnesium and dosing oxygen at room temperature under UHV conditions. Monochromatic synchrotron radiation photoemission technique was applied to investigate the reaction process by monitoring the core level transitions and valence band. Interfacial reactions were obviously observed through the changes of oxidation states of Mg, Ga and As. The oxidation state of Mg was almost reversed after the oxidation of Mg overlayer compared to the reaction process with GaAs substrate. Physical and chemical phenomena occurred during the deposition and oxidation were discussed based on the photoemission results