Br2adsorption on GaAs(110) and surface etching at low temperature

Abstract
The adsorption and reactivity of Br2 on GaAs (110) was studied in the temperature range of 25≤T≤300 K with photoemission spectroscopy. Initial Br2 adsorption was dissociative at all temperatures with Br bonding to both As and Ga. Thermally activated etching was observed after warming up a surface with condensed Br2 multilayers. AsBr3 formation was evident at 50–100 K but this species desorbed for T≥150 K. GaBr3 formation also occurred and this species remained on the surface until ∼250 K. Br-Ga and Br-As surface species were evident for all temperatures. The erosion of the (110) surface was nearly stoichiometric.