Interelectrode Metal Migration on GaAs

Interelectrode material transport in unpassivated and in PECVD-Si3N4-passivated GaAs planar structures was studied using X-Ray-Photoelectron Spectroscopy (XPS). Even in the passivated devices, metal migration through the GaAs/Si3N4-interface was observed. It depends strongly on the GaAs surface conditions prior to nitride deposition. An ammonia treatment of the GaAs surfaces is presented which results in high stability due to a re, duction of As2O3 and of elemental As on the GaAs surface as established by XPS.