Low-Temperature Performance of Nanoscale MOSFET for Deep-Space RF Applications

Abstract

RF characteristics of a nanoscale MOSFET are measured and analyzed at temperatures ranging from 4.2 to 300 K for deep-space RF applications. This device shows a 197-GHz 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> ) and a 162-GHz maximum oscillation frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) when operating at liquid-helium temperature, which represent a 60% and 80% improvement compared to room temperature performances, respectively, f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> continually improves as the temperature decreases to near-liquid-helium temperature due to the decrease of gate capacitance (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gg</sub> ). f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> decreases as the temperature is lowered below 25 K due to the increase of gate resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ).