X-ray photoelectron spectroscopy study of GaAs surface exposed to a rf hydrogen plasma

Abstract

Using x-ray photoelectron spectroscopy analysis, it is shown that hydrogen plasma treatment of the gallium arsenide surface induces a modification of the superficial stoichiometry. The resulting surface composition presents a gallium enrichment and is the same whatever the initial composition. The departure from the stoichiometry increases with the plasma power. After the plasma treatment, the absence of arsenic oxidation and an abnormal gallium suboxidation state is observed. Moreover, these new gallium and arsenic oxidation states are stable when the sample is left in the air.