Stability of sulfur-treated InP surface studied by photoluminescence and x-ray photoelectron spectroscopy

Abstract

The degradation behavior of the sulfur-treated InP surface at relatively low temperature has been investigated with x-ray photoelectron and photoluminescence (PL) spectroscopy. The results showed that the treated surfaces were oxidized to In2O3, InPO3, and InPO4 at 250 degrees C and in a vacuum of 10(-3) Torr for 20 min. As the holding time for S-treated InP under a vacuum of 10-3 Torr increased, the PL peak caused by the band edge transition decreased without the formation of oxides. It was therefore suggested that the decrease of the PL intensity for S-treated InP is only related to the generation of phosphorous vacancies at the surface, not to oxide formation. The usefulness of a thin S overlayer on LII-V semiconductors was also discussed. (C) 1997 American Institute of Physics.