Performance of AlGaAs∕InGaAs∕GaAs Pseudomorphic High Electron Mobility Transistor as a Function of Temperature

An pseudomorphic high electron mobility transistor (pHEMT) with double δ-doping carrier supply layers was fabricated and characterized. Estimates of typical device characteristics (extrinsic transconductance , drain current density , threshold voltage , current gain cut-off frequency , maximum frequency of oscillation , noise behavior, and large signal measurements) were made. A series of experiments was conducted to assess the effects of temperature on pHEMT. A peak of was obtained from the fabricated pHEMT with a gate length of for room-temperature operation. The transistor characteristics showed evidence of high breakdown voltages. With respect to the variation in two-terminal gate-drain breakdown voltage, this device had a positive temperature coefficient from , and a negative temperature coefficient at temperatures surpassing . Strikingly, high-frequency on-wafer measurements on the fabricated pHEMT were made up to , revealing nearly no change in . Not only was the device characterized and the complicated mechanisms at various temperatures elucidated, but also the favorable potential of the presented pHEMT for high-temperature and high-frequency applications was determined.