Shallow and deep donors in transport properties of N-implanted 6H-SiC

Transport properties of N-implanted 6H-SiC samples are studied between 30 and 1000 K. The Hall effect and mobility behaviors are interpreted in the framework of a two impurity level model. The temperature dependence of mobility is calculated including all scattering processes which are of importance for SiC in the studied temperature range. Our results show that the impurity center associated with the hexagonal site behaves like a shallow level, whereas that associated with the cubic site is well described by a localized state.