TIME-DEPENDENCE CALCULATION OF THE BREAKDOWN RATE FOR ELECTRICAL BREAKDOWNS IN VITREOUS SOLIDS

The anomalous behaviour of different physical quantities in vitreous solids contrary to the behaviour in crystalline solids, mainly the dielectric behaviour, can be described by the effect of a system of additional low-energy excitations in these solids. This also applies to the amorphous SiO2-layers in MOS structures. Therefore, a model of breakdown behaviour is developed basing on the assumption that there are fluctuations of the correlated local electrical fields and low-energy excitations present in these layers. On this basis, the time dependence of breakdown rate is determined. By these calculations. a good correspondence of the experimentally and theoretically determined characteristics is obtained. In these calculations, it should be paid attention to the fact that the properties of the vitreous solids and the character of the internal interaction change by breakdowns already occurred.