[11a-70A-1~10] 15.6 IV族系化合物（SiC）

▼ [11a-70A-8] An anomalous negative shift of flat-band voltage of NO annealed SiO₂/4H-SiC MOS capacitors

〇(D)Taehyeon Kil¹、Atsushi Tamura¹、Koji Kita¹ (1.Dept. of Materials Engineering, The Univ. of Tokyo)

キーワード：Anomalous negative shift of flat-band voltage, SiO2/4H-SiC MOS capacitor

NO post-oxidation annealing (NO-POA) process is a beneficial method to reduce the D_it of SiO₂/4H-SiC interface and improve the MOSFET performance. One of the drawbacks of this POA is the negative shift of threshold voltage. However, the origin of this phenomenon is not clarified yet. In this work, we investigated the effect of NO-POA with varying durations on flat-band voltage (V_FB) of MOS capacitors. With increasing NO-POA duration after dry oxidation, fixed oxide charges at the interface decreased to less than 10¹⁰ cm^-2. Moreover, there was an anomalous negative shift of extrapolated V_FB (more than 0.5 V), which would be related to the nitrogen concentration at the interface.