Physical modeling of direct current and radio frequency characteristics for InP-based InAlAs/InGaAs HEMTs**Project supported by the National Natural Science Foundation of China (Grant Nos. 61404115 and 61434006), the Postdoctoral Science Foundation of Henan Province, China (Grant No. 2014006), and the Development Fund for Outstanding Young Teachers of Zhengzhou University (Grant No. 1521317004).

Abstract

Direct current (DC) and radio frequency (RF) performances of InP-based high electron mobility transistors (HEMTs) are investigated by Sentaurus TCAD. The physical models including hydrodynamic transport model, Shockley–Read–Hall recombination, Auger recombination, radiative recombination, density gradient model and high field-dependent mobility are used to characterize the devices. The simulated results and measured results about DC and RF performances are compared, showing that they are well matched. However, the slight differences in channel current and pinch-off voltage may be accounted for by the surface defects resulting from oxidized InAlAs material in the gate-recess region. Moreover, the simulated frequency characteristics can be extrapolated beyond the test equipment limitation of 40 GHz, which gives a more accurate maximum oscillation frequency (fmax) of 385 GHz.