The cryogenic and high temperature characterization of Al0.52In0.48P/In0.2Ga0.8As high electron mobility transistors (HEMTs) with 1 mum-long gates, grown by gas-source molecular-beam epitaxy is being reported. Bias-stress measurements at 77 K in the dark showed only 18 mV threshold voltage shift, confirming that trapping effects are negligible in this material system. Successful operation of these HEMTs at temperatures up to 300-degrees-C has been achieved. These results suggest that AlInP/InGaAs HEMTs have potential for cryogenic and high temperature applications.
