75 nm Gate Length PHEMT With f max = 800 GHz Using Asymmetric Gate Recess: RF and Noise Investigation

Abstract

We report a high maximum frequency of oscillation ( f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) and a current-gain cutoff frequency ( f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> ) of 800 and 260 GHz, respectively, with pseudomorphic high-electron mobility transistor (PHEMT), using an InGaAs/InAs composite channel and an asymmetric gate recess. This result was achieved with long gate length L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> = 75 nm. The RF small signal equivalent circuit (SSEC) was extracted up to 110 GHz. Moreover, noise parameters extraction gives a minimum noise figure (NF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</sub> ) of 0.8 dB (with associated gain G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ass</sub> = 16 dB) and 1.8 dB (with associated gain G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ass</sub> = 11.6 dB) at 40 and 94 GHz, respectively. In this study, the gate leakage current was considered in the SSEC of the transistor ( g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gf</sub> and g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">df</sub> ) and for extraction of the noise parameters.