Anomalous behaviour of dielectric dispersion properties of evaporated silicon oxide films under DC high electric fields

It is observed that AC dispersion properties of evaporated silicon oxide film are largely affected by a DC biasing voltage. This anomalous effect is explained in connection with the previously reported experimental results of electrically excited thermally stimulated current (ETSC). Numerical calculation of this effect is based on a two-site hopping model and taking into consideration the internal field gives a hopping distance in a two-site pair of about 5.7 ¿¿, which is very close to the lattice constant of quartz. It is concluded that the two-site hopping pair probably originates from ionic jumps between nearest vacancies. As far as the experimental results are concerned, there are no contraditions in the interpretations of the DC and AC conductances in terms of independent mechanisms.