Glow spots and breakdown in GaAs transistor structure

A study of field effect transistors with GaAs structure and a Schottky gate established that the cause of irreversible changes preceding breakdown in such devices is the localized emission of radiation and the appearance of glow spots following the formation of multifilar and multidomanial states. Current voltage characteristics were measured through the operating range into the cut off range. Glow spots with attendant irreversible changes in the interelectrode (drain-gate) region were recorded before and during breakdown. Breakdown of the drain domain is preceded by melting of gallium in the brightest spots in this region and migration of the liquid toward the gate, after formation of craters in the n-GaAs film from which drops of liquid gallium had exuded to settle on the surface. Breakdown of the Schottky barrier preceded by isothermal instability with attendant redistribution of the electric field in the grain gate region.