An extraction method of channel resistance for analysis of carrier scattering mechanism in SiC trench MOSFETs

We propose an experimental method for evaluating channel mobility that eliminates the parasitic series resistance in trench metal-oxide-semiconductor field-effect transistors (MOSFETs). It is found that the parasitic resistance increases with increasing temperature, which is mainly caused by optical phonon scattering in the drift layer of trench MOSFETs. The measurement method in which the current path is from the surface drain electrode to the source electrode underestimates the effective mobility because of the voltage drop caused by the drift layer resistance at the bottom of the trench gate. The proposed measurement method avoids this underestimation.