Characterization of Oxidized GaAs (001) Surfaces Using Temperature Programed Desorption and X-Ray Photoelectron Spectroscopy

Abstract

Temperature programed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were carried out on oxidized GaAs (001) surfaces in order to obtain insight into the durability of the oxide masks used in in situ selective-area processing. The TPD spectra comprised three successive desorption peaks showing the desorption of arsenic at 390°C, Ga 2 O at 475°C, and both Ga 2 O and arsenic above 500°C. XPS revealed the disappearance of As oxide and an increase of Ga oxide during the first desorption. The coexistence of two forms of Ga oxide, i.e., Ga 2 O and Ga 2 O 3 , is suggested, and a mechanism of oxide desorption is proposed.