High-Frequency Performance of Subthreshold SOI MESFETs

Results from silicon-on-insulator (SOI) MESFETs designed for subthreshold operation are presented. The transistors have subthreshold slopes as low as 78 mV/dec and off-state drain currents approaching 1 pA/μm. Drain current saturation can be achieved with drain voltages of less than 0.5 V and with output impedance>100 M/spl Omega//spl middot/μm. The cutoff frequency of a 500-nm gate length device exceeds 1 GHz at currents significantly less than 1 μA/μm. These results suggest that subthreshold SOI MESFETs might have useful applications in mixed-signal, micropower circuit design.