Comparative investigation of GaAsSb/InGaAs type-II and InP/InGaAs type-I doped–channel field–effect transistors

DC performance of GaAsSb/InGaAs type-II and InP/InGaAs type-I doped-channel field-effect transistors (DCFETs) is demonstrated and compared by two-dimensional simulated analysis. As compared with the traditional InP/InGaAs DCFET, the GaAsSb/InGaAs DCFET exhibits a higher drain current of 8.05 mA, a higher transconductance of 216.24 mS/mm, and a lower gate turn-on voltage of 0.25 V for the presence of a relatively large conduction band discontinuity ($\Delta E_c\approx$ 0.4 eV) at GaAsSb/InGaAs heterostructure and the formation of two-dimensional electron gas in the $n^+$-InGaAs doping channel. However, due to the tunneling effect under large gate-to-source bias, it results in considerably large gate leakage current in the GaAsSb/InGaAs DCFET.