Characterization of 4H-SiC–SiO2 Interfaces by a Deep Ultraviolet Spectroscopic Ellipsometer
We have characterized 4H-SiC–oxide interfaces fabricated by thermal oxidation of SiC using spectroscopic ellipsometry in the wide spectral range from visible to deep UV region. It was found that there exists an interface layer, around 1 nm in thickness, regardless of the oxide thickness from 15 nm to 40 nm. The optical constants of the interface layer have similar spectral dependence to those of SiC, though the absolute value of the refractive indices is 0.5–1 larger than that of SiC. We have discussed the structure of the interface layer based on the oxidation mechanism of SiC, like the Si-emission model.
Amador Pérez-Tomás, Philippe Godignon, Miquel Vellvehí and Pierre Brosselard
H. Seki et al., "Characterization of 4H-SiC–SiO2 Interfaces by a Deep Ultraviolet Spectroscopic Ellipsometer", Materials Science Forum, Vols. 615-617, pp. 505-508, 2009