Reliability of Large-Area Gate Oxide on the C-Face of 4H-SiC
This paper discusses the issues regarding reliability of large-area (up to 9mm2) gate oxide on the C-face of 4H-SiC. We first show that the initial failure in TDDB characteristics of large area gate oxide is strongly correlated with the surface-defect density. Using wafers with low surface-defect density wafers, scaling analysis of the area-dependence of TDDB characteristics has been performed. It has shown that the reliability of a large area gate oxide is dominated by initial and random failures. Further, we have shown that, by optimizing the temperatures of post-oxidation anneal in hydrogen atmosphere, the random failures of TDDB characteristics are substantially reduced.
Amador Pérez-Tomás, Philippe Godignon, Miquel Vellvehí and Pierre Brosselard
T. Hatakeyama et al., "Reliability of Large-Area Gate Oxide on the C-Face of 4H-SiC", Materials Science Forum, Vols. 615-617, pp. 553-556, 2009