A mild electrochemical sulfur passivation method for GaAs(100) surfaces

Abstract

We have developed a mild electrochemical sulfurization technique which can form a very thick sulfide layer on GaAs(100) surface. This sulfide layer is quite stable in air. The photoluminescence spectrum of such anodic sulfurized GaAs surface shows a large intensity enhancement as compared with that of as-etched GaAs samples. No visual intensity decay occurs under the laser beam illumination after the sample has been maintained in air for more than seven months. The structure and composition of the passivation layers are investigated by x-ray photoelectron spectroscopy and the mechanism of layer formation is discussed. © 1995 American Institute of Physics.