Quasi-static capacitance methods were used to study defect formation in hydrogenated amorphous material, and to test the defect-pool model. Numerical calculations demonstrated that, within the framework of this model, changes in the density of dangling bond states which were induced by thermal bias annealing were reflected in the shape of capacitance versus gate bias curves. Although some details of the curves for Al/SiO2/Si structures could not be explained by this model, the main predicted characteristics were observed. It was confirmed that a bump of dangling bond states was created below or above the mid-gap; depending upon whether the Fermi level moved towards the conduction or valence band during thermal bias annealing.

J.P.Kleider, F.Dayoub: Physical Review B, 1997, 55[16], R10181-4