High-frequency characteristics and saturation electron velocity of InAlAs/InGaAs metamorphic high electron mobility transistors at high temperatures

We fabricated InAlAs/InGaAs metamorphic high electron mobility transistors (MHEMTs) with several indium contents. High-frequency performance of the MHEMTs was measured at high temperatures up to 473 K. By the delay time analysis, we have estimated saturation electron velocity. Temperature dependence of the saturation electron velocity for the MHEMTs with higher indium contents exhibits deviations from a theory.