Sinusoidal Steady State Analysis on 4H--SiC Buried Channel MOSFETs

With the combined use of the drift-diffusion (DD) model, experimental measured parameters and small-signal sinusoidal steady-state analysis, we extract the Y-parameters for 4H--SiC buried-channel metal oxide semiconductor field effect transistors (BCMOSFETs). Output short-circuit current gain G and Mason's invariant U are calculated for extrapolating unity current gain frequency in the common-source configuration f_T and the maximum frequency of oscillation f_max, respectively. Here f_T=800MHz and f_max=5GHz are extracted for the 4H--SiC BCMOSFETs, while the field effect mobility reaches its peak value 87cm²/Vs when V_GS=4.5V. Simulation results clearly show that the characteristic frequency of 4H--SiC BCMOSFETs and field effect mobility are superior, due to the novel structure, compared with conventional MOSFETs.