Quantitative Characterization of Near-Interface Oxide Traps in 4H-SiC MOS Capacitors by Transient Capacitance Measurements

A method to characterize near-interface oxide trap density in SiC MOS capacitors using transient capacitance measurements was investigated, taking account of the distribution of de-trapping time of traps of various locations in oxide. The measurements at room and low temperatures enables us evaluate the responses of the raps of spatially deep and shallow locations, respectively. We found that the sample with low Dit showed smaller density of near-interface traps especially in spatially shallow region in the oxide.