MOSFET Small-Signal Model Considering Hot-Carrier Effect for Millimeter-Wave Frequencies

The hot-carrier effect, which is caused by the generation of interface states, is the main degradation mechanism for MOSFETs. Predicting the degradation of circuit performance due to the hot-carrier effect is important for practical circuit design. In this paper, we propose a small-signal model considering the hot-carrier effect by establishing time-dependent model parameters, which is verified by small-signal simulation and measurement for 40-nm-process MOSFETs at millimeter-wave (mmW) frequencies. In the proposed small-signal model, the shift of relaxation time of the non-quasi-static (NQS) effect is investigated and verified for mmW frequencies for the first time. By comparing simulation and measurement results, it is shown that the shift of relaxation time of the NQS effect should be considered for the prediction of MOSFETs performance degradation at mmW frequencies.