A very low density (less than 1010/cm2) residual discrete energy-level interface trap, at 0.228eV from the mid-gap, was detected on crystalline samples which were covered by a thermally grown oxide. By using Shockley-Read-Hall recombination kinetics, the energy level was shown to have a linewidth of less than 0.020eV. On the basis of present and previous data, this residual interface trap species was attributed to a dopant impurity rather than to amphoteric Si dangling bonds.

Evidence for discrete interface traps on thermally grown thin silicon oxide films J.Cai, C.T.Sah: Applied Physics Letters, 1999, 74[2], 257-9