Low-temperature performance of nanoscale MOSFET for deep-space RF applications

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(T)) and-a 162-GHz maximum oscillation frequency (f(max)) when operating at liquid-helium temperature, which represent a 60% and 80% improvement compared to room temperature performances, respectively. f(T) continually improves as the temperature decreases to near-liquid.-helium temperature due to the decrease of gate capacitance (C-gg). f(max) decreases as the. temperature is lowered below 25 K due to the increase of gate resistance (R-g).X111817sciescopu