N 2 – H 2 remote plasma nitridation for GaAs surface passivation

A remote N2–H2 (a mixture of 97% N2–3% H2) rf plasma nitridation procedure has been developed to form a very thin (∼5Å) GaN layer successful in the electronic and chemical passivation of GaAs (100) surfaces. The interaction of the plasma with the GaAs surface has been controlled in situ and in real time by spectroscopic ellipsometry. The stability of the chemical and electronic passivation is demonstrated by the nonoxidation and by the nondecaying behavior of the photoluminescence efficiency of the GaAs passivated surface over months of air exposure.