A study of deep traps at the SiO2/6H-SiC interface relying upon the nonequilibrium field effect

The nonequilibrium field effect associated with deep surface states at the SiO2/6H-SiC interface has been observed and studied in a 6H-SiC MOSFET of d epletion-accumulation type. An analysis of the relaxation of channel conduc tance at elevated temperatures upon filling of the surface traps with noneq uilibrium carriers has shown that the energy distribution of the surface tr aps has the form of a narrow Gaussian peak in the upper half of the 6H-SiC band gap, with a peak energy E-C - E-tm = 1.19 eV, peak width DeltaE(t) app roximate to 85 meV, and electron capture cross section sigma (n) approximat e to 10(-14) cm(2). These surface states are believed to have the fundament al nature of "oxidation defects" similar to P-b centers in the SiO2-Si syst em (of dangling silicon bonds). (C) 2001 MAIK "Nauka/Interperiodica".