Total Dose Radiation Response of Nitrided and Non-nitrided SiO2/4H-SiC MOS Capacitors

The total dose radiation response of nitrided and non-nitrided n-type 4H-SiC is reported for metal oxide semiconductor capacitors exposed to 10-keV X-rays under positive bias. The radiation response is affected strongly by differences in the SiC band gap and interface/near interface SiO₂ trap density from typical Si MOS devices. Significantly higher net trapped positive charge densities were observed in nitrided n-SiC MOS capacitors compared to the non-nitrided samples. The mechanisms contributing to the differences in the charge trapping in these devices are discussed. Differences in the interfacial layer between SiO₂/Si and SiO₂/SiC are responsible for the observed dissimilarities in charge trapping behavior