Some aspects of GaAs FET reliability

The results of a short study into the reliability and failure modes of GaAs FETs are presented. Two failure modes have been observed during this study, and improved fabrication techniques that reduce their occurrence have been examined. The results obtained indicate that extremely reliable devices can be manufactured with a predicted mean time to failure in excess of 10 7 hours at junction temperatures of 70°C. Room temperature life tests in excess of ½ million device hours lend support to these predictions.