Impact of Reduced Gate-to-Source Spacing on Indium Phosphide High Electron Mobility Transistor Performance

摘要

Indium phosphide (InP)-based high electron mobility transistors (HEMTs) withan offset gate enable higher maximum oscillation frequency (f_(MAX)) valuesbecause of the resulting reduction in gate-to-source resistance. Following thisapproach, improved direct current (DC) characteristics and cutoff frequencies(f_T/f_(MAX)＞410/710 GHz with L_G = 50 nm) are shown with respect to centeredgate devices. However, HEMTs with an offset gate show degraded noise performancescompared with centered gate devices because of a higher gateleakage current. The results show that offsetting the gate closer to the source isnot desirable for ultra-low-noise performance.