Characterisation of silicon carbide MOSFETs using Three Level Charge Pumping

The application of Three Level Charge Pumping is used to characterise the SiC-SiO₂ interface of 6H-silicon carbide MOSFETs. At room temperature, the characteristics found are different in appearance to those found in conventional silicon MOSFETs, but are used, in conjunction with a quasistatic CV measurement, to determine both interface state densities and emission/capture cross sections. At elevated temperatures, the three level charge pumping characteristics begin to degenerate at the frequencies required for determination of emission and capture cross sections. The different room temperature characteristics are attributed to a high level of negative trapped oxide charge, which may tunnel from border states during long step times, and supplement the expected charge pumping current