Cryogenic Small Signal Operation of 0.18 μm MOSFETs

In this work we present the cryogenic small signal ac performance of MOSFETs from a commercially available 0.18 μm technology node. The peak cut-off frequency (f
_T
) increases from 63GHz to 90GHz at 77K and the f
_max
increases from 50GHz to 78GHz at 77K. A simple small signal sub-circuit model is used to understand the dependence of device parameters with temperature. The understanding of cryogenic small signal performance is crucial for the development of RF CMOS integrated circuits for low temperature applications.