HYDROGEN AND NITROGEN PLASMA TREATMENT EFFECTS ON SURFACE-PROPERTIES OF GASB AND INGAASSB

P-i-n diodes of GaSb/InGaAsSb were treated in atomic hydrogen and atom ic nitrogen flows in a microwave plasma crossed beams machine and in d irect H-2 and N-2 plasma. The first type of treatment led to degradati on of reverse currents of the diodes. Direct plasma treatments in H-2 alone also led to a deterioration of the surface properties. However, combined treatment at 450 degrees C in direct H-2 and N-2 plasmas impr oved the reverse currents and photoluminescence (PL) intensity by more than an order of magnitude. Formation of a passivating GaN layer at t he surface of GaSb depleted of Sb by preliminary intense H-2 treatment is thought to be responsible for the effect.