INSTABILITIES IN 6H-SIC MOS STRUCTURES

In this paper, we present a study of some instabilities observed on p- type 6H-SiC MOS structures by different measurement techniques of capa citance, charge and current, as well as by Thermally Stimulated Ionic Current (TSIC). The analysis of hysteresis and deformation of C-V curv es show the presence of interface states and oxide traps, with a densi ty of about 5 to 7 x 10(10) eV-1.cm 2 at midgap and a peak of 3 x 10(1 2) eV-1.cm-2 at E = E(v) + 0.53 eV. TSIC spectra show the presence of mobile charges in a concentration range of 10(12) cm-2. The behaviour of the inversion layer is also studied at different temperatures. We s how that the minority carrier generation is assisted by deep levels (g eneration centers).