Simple Requirement to Passivating Film/GaAs Interface for Avalanche Breakdown Suppression.

Shown recently superfast (picosecond range) switching and copious sub-THz emission from a GaAs avalanche n+-p-n0-n+ bipolar junction transistor (BJT) makes the task of premature surface breakdown suppression critically important. Here we show that surface breakdown can be suppressed even for negatively beveled mesa by creating sufficiently high (~1012 cm-2) density of negative surface charge. This charge can be cause by surface-trapped avalanche-generated electrons or, alternatively, formed on the semiconductor/passivation film interface by proper selection of a passivation material. In particular we observed excellent passivation properties of a chalcogenide glass. [ABSTRACT FROM AUTHOR]