fmax=800 GHz with 75 nm gate length and asymmetric gate recess for InGaAs/InAlAs PHEMT

In this paper, we present a high maximum frequency of oscillation (f_max) and a current-gain cutoff frequency (f_T) of 800 GHz and 260 GHz respectively with pseudomorphic high-electron mobility transistor (PHEMT), using a composite, InGaAs/InAs/InGaAs channel and an asymmetric gate recess. This result was achieved with long gate length L_G = 75 nm. The noise performance has been explored until 110 GHz, and gives a minimum noise figure NF_min = 0.8 dB (1.8 dB) with associated gain G_ass = 16 dB (11.6 dB) at 40 GHz (94 GHz). Moreover extending the drain recess length to 225 nm and reducing the gate to source distance by 200 nm allows a f_max = 1.2 THz.