Long Term Stability of InGaAs/AlInAs/GaAs Methamorphic HEMTs

The long term stability of M-HEMTs has been evaluated by means of hot electrons stress test carried out at high ambient temperature. Devices demonstrate a good stability under high temperature thermal storage (T = 200 degreesC) or hot electron stress test at room temperature. Moreover, under very severe stress conditions (hot electron stress test at very high temperature), devices show large degradation in the I-V characteristics i.e. positive threshold voltage shift, a degradation of the gate Schottky diode, and increase of the parasitic drain resistance. The degradation are activated by both high temperature and high electric field.