Chemical nitridation of GaAs(100) by hydrazine-sulfide water solutions

We have developed for GaAs a new nitrogen chemical surface passivation. The passivation procedure that can be justified from chemical reasonings, cons ists of a wet treatment by a mixture of hydrazine and sodium sulfide soluti ons, and is proposed to produce an essentially Ga-terminated (1 0 0) surfac e covered with a monolayer of chemisorbed nitrogen. The as-treated surface reveals clear (1 x 1) RHEED pattern that confirms the formation of the thin and coherent GaN him. The chemical nitridation of GaAs surface produces an increase of photoluminescence intensity. This effect is found to be strong er and more stable in air ambient under above band-gap light excitation tha n that produced by sulfide passivation. (C) 2000 Elsevier Science Ltd. All rights reserved.