Abstract
The final-state oxidation products and their distribution in thin native oxides (30–40 Å) on GaAs have been studied using x-ray photoelectron spectroscopy in conjunction with chemical depth profiling. Extended room-temperature-oxidation conditions have been chosen to allow the native oxide to attain its equilibrium composition and structure. The work emphasizes the use of chemical depth-profiling methods which make it possible to examine the variation in chemical reactivity of the oxide structure. A minimum of two distinct regions of Ga2O3 with differing chemical reactivity is observed. Arsenic oxide species show one distinct phase at the outer oxide surface. Intensity analysis indicates an oxidized Ga to oxidized As composition ratio of 2:1 at the outer surface, which changes to approximately 10:1 at the oxide/GaAs interface. Chemical shift data indicate the presence of As2O3 in the oxide together with an elemental As overlayer at the interface. A change in relative charge transfer between oxygen and both arsenic and gallium–oxide species is observed in the region of the interface. The presence of mixed As/Ga oxides and different gallium oxide coordination environments is also discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
