GaAs FET Failure Mechanisms Due to High Humidity and Ionic Contamination

Failure mechanisms resulting from the concurrent exposure to high relative humidity, ion contamination, and temperature cycling were studied in commercially available, low noise GaAs fieldeffect transistors (FETs). This type of device will be applied in such adverse environmental conditions. Devices with Al and Au/refractory gates from four different suppliers were studied. Au/refractory gate devices were less susceptible to degradation as a result of the hostile environment. Failure mechanisms were determined and correlated with the electrical degradation of the devices.