Analyses on Small-Signal Parameters and Radio-Frequency Modeling of Gate-All-Around Tunneling Field-Effect Transistors

The small-signal parameters of gate-all-around tunneling field-effect transistors (GAA TFETs) with different gate lengths were extracted and analyzed in terms of their gate capacitance, source-drain conductance, transconductance, distributed channel resistance, and inversion layer length. Because of the unique current drive and inversion layer formation mechanisms of a TFET compared to a conventional MOSFET, the gate-bias dependence values of the primary small-signal parameters of a GAA TFET also differ. Based on understanding these parameters, the high-frequency performances of GAA TFETs were investigated using a technology computer-aided design simulation. A nonquasistatic radio-frequency model was used to extract the small-signal parameters, which were verified up to 100 GHz. The modeling results showed excellent agreement with the Y-parameters up to the cutoff frequency f_T.