ELECTRON-STIMULATED DESORPTION AND ADSORPTION SITES OF CHLORINE ON GAAS(110) SURFACES

The adsorption of chlorine on GaAs(110) surfaces was followed by using a Kelvin probe as well as ultraviolet photoemission, Auger electron, and low-energy electron energy-loss spectroscopy. The bombardment of c hlorinated surfaces with electrons promotes the desorption of the adso rbate. Electron-stimulated desorption from chlorinated GaAs(110) surfa ces reveals two different chlorine adsorption sites, which are equally occupied after chlorine adsorption and before electron-stimulated des orption. The assignment of two different adsorption sites of chlorine on GaAs(110) surfaces to Ga-Cl and As-Cl bonds is supported by further experimental observations. Below one monolayer, one chlorine atom wil l be bound to each of the Ga and As surface atoms while for larger chl orine uptake Ga-Cl2 and As-Cl2 complexes might possibly form.