[25p-P11-1~16] 13.7 化合物及びパワーデバイス・プロセス技術・評価

▲ [25p-P11-13] Investigation Trap Density in Oxide Layer of 4H-SiC MOS Capacitor During Long-Time Aging at 400^oC Ambient

〇Cuong Van Vuong¹、Kaho Koyanagi¹、Tatsuya Meguro¹、Shin-Ichiro Kuroki¹ (1.Hiroshima Univ.)

キーワード：4H-SiC MOS capacitor, TiN, Metal gate, High-Temperature Reliability, Near Interface Traps

In this research, the the distribution of trap density in the oxide layer of 4H-SiC MOS capacitor with Al and TiN metal gate during the aging process at 400ºC in N₂ ambient was investigated. By applying the modified distributed circuit model, the results showed that the interface trap density decreased with aging time for both Al and TiN metal gate. However, after 100-hour aging, the decay constant of the capacitor with Al based is higher than that of TiN based. As a result, the near interface trap density of the capacitor with Al metal gate is much higher than that of the capacitor based on TiN metal. A much lower near interface trap density accounts for the high-temperature reliability of the integrated circuit based on 4H-SiC MOSFET with TiN metal gate. This result demonstrates that TiN is a promising candidate for harsh environment applications.