Reliability of Power Gaas FET's-Au Gates and Al-Au Linked Gates

An investigation of the reliability of two types of commercial microwave power GaAs FET's has been carried out. Mean-time-to-failure data for a device mounted face-up with Al gates but without an Al-Au couple is presented and similar data for a "flip-chip" mounted Au-refractory gate device is reviewed. The failure mechanisms for both devices are described.