III–V surface processing

Abstract

The results of exposing cleaved (110) and polished or metal organic chemical vapor deposition (MOCVD) grown (100) single crystal InP and GaAs surfaces to various treatments are reported. The formation of hydrocarbon covered, hydrogen terminated surfaces is shown to provide short term protection against the contamination typically observed when clean surfaces are exposed to air. This protective layer is readily removed on exposure to ultraviolet/ozone irradiation resulting in a surface covered with a thin stoichiometric native oxide which provides a more permanent surface passivation. The thickness of oxides, prepared using this procedure, can be controlled to make them compatible with most III–V process steps. Thermal desorption of the oxides in appropriate ambients yields stoichiometric surfaces appropriate for epitaxial overgrowth.