Reliability studies of one-micron Schottky gate GaAs FET

Failure modes have been studied experimentally on a low-noise one-micron aluminum gate GaAs FET. Several life tests, including high temperature storage, power burn-in, and gate biasing at elevated temperature, were carried out on more than 200 samples. It has been revealed that gradual degradation of source and drain contact resistance is the major life-determining failure mode. MTTF was estimated to be about 10⁹hours for channel temperature of 80°C. Surge tests were also carried out. In some specimens, reversible drift of electrical parameters was observed. This instability seems to be related with deep level trapping centers in the GaAs epitaxial layer substrate interface.