The 1.1 eV deep level in 4H-SiC

Temperature dependent Hall effect and optical absorption measurements of vanadium doped semi-insulating 4H-SiC samples are reported along with optical admittance spectroscopy measurements of related material. In addition to the deep donor and acceptor levels of substitutional vanadium, E/sub C/-1.6 eV and E/sub C/-0.7 eV respectively, we report an additional level at 1.1 eV. This level has been seen in undoped 4H-SiC by optical admittance spectroscopy which has also detected a similar level at E/sub C/-1.0 eV in 6H-SiC, and by temperature dependent Hall effect in vanadium doped material. Optical absorption measurements of the vanadium intra-center absorption show that this level is not either of the two substitutional vanadium levels. SIMS measurements support the hypothesis that the 1.1 eV level is a complex of vanadium and another impurity, possibly titanium.