Impact of Silicon Nitride Stress on Defects Generation in 4H-SiC and the Effect of Sacrificial Oxidation on Defects Reduction

The impact of silicon nitride (Si₃N₄) stress on 4H-SiC has been investigated. Current-voltage (I-V) measurements on Schottky barrier diode show that Si₃N₄ films thicker than 100 nm degrade both the ideality factor and Schottky barrier height. A 45-nm sacrificial oxidation effectively reduces defects from a 100-nm-thick Si₃N₄ layer, but defects persist with films over 300 nm. Interface state density of metal oxide semiconductor capacitor with a 44-nm-thick gate oxide confirms the effectiveness of sacrificial oxidation in mitigating defects.