Papers by Keyword: SiC-SiO₂ Interface

Abstract: The effect of using two different polytypes, 4H-SiC and 6H-SiC, on the performance of (0001) SiC MOSFETs has been studied. 4H-SiC and 6H-SiC MOSFETs have been fabricated with deposited gate oxides followed by oxidation in dry O2 or NO. Device parameters, particularly field-effect mobility, inversion sheet carrier concentration and Hall mobility have been extracted. We have also compared the mobility-limiting mechanisms of (0001) 4H and 6H-SiC MOSFETs and found that inversion mobility can be further improved in 4H-SiC, but not 6H-SiC.

Abstract: To study the mobility limiting mechanisms in (0001) 4H-SiC and 6H-SiC MOSFETs, physics based modeling of the inversion mobility of has been done. Two very different limiting mechanisms have been found for 4H-SiC and 6H-SiC MOSFETs. The mobility in 6H-SiC MOSFETs is limited by phonon scattering while the 4H-SiC MOSFET mobility is limited by Coulombic at low electric fields and surface roughness scattering at high electric fields.

Abstract: 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.