Effect of NO annealing conditions on electrical characteristics of n-type 4H-SiC MOS capacitors

This paper presents the results of the effect of NO annealing temperature a nd annealing time on the interfacial properties of n-type 4H-SiC MOS capaci tors. The interface trap density measured by conductance technique at 330 d egrees C decreases as NO annealing temperature increases from 930 degrees C to 1130 degrees and annealing time is extended from 30 min. to 180 min. Th e changes in effective oxide charge between room temperature and high tempe rature are calculated and used to compare different n-type 4H-SiC MOS capac itors. Higher NO annealing temperature and longer NO annealing time decreas e the change in effective oxide charge, which is consistent with the NO ann ealing temperature/time dependence of interface trap density measured by co nductance technique. However, NO annealing temperature has more pronounced influence on the SiO2/SiC interface than NO annealing time.