Reliability analysis of the gradual degradation of semiconductor devices

A review of the recent results on accelerated aging of both power and low-noise GaAs FETs indicates that the major failure mode occurs by gradual deterioration and not by the usually (implicity) assumed catastrophic device failure. It is shown that assuming catastrophic degradation when devices actually fail gradually can lead to incorrect device reliability predictions. The analysis of accelerated aging results for a gradual degradation failure mode is indicated.