Prebreakdown channels on the splits of dielectric films

Summary form only given. A novel approach to the investigation of physical phenomena in leakage channels leading to breakdown in dielectric films is discussed. It was shown previously that the properties of leakage channels in thin amorphous dielectric films are identical to those revealed on the relevant specially fabricated splits. The investigated films were deposited on metal (low-resistance crystalline silicon) substrates, which were split together with the film. The line of the split was scanned with small mercury probes. The registered currents were in the range from 10^-11 to 10^-5 A for an electric field value in the film of about 10⁵-10⁶ V/cm. Leakage channels with conductivity exponentially exceeding mean values dominated in the case in which the diameter of the mercury probe was large enough. The characteristics of current-voltage curves as well as the results of accompanying noise measurements are consistent with the mesoscopic nature of the studied objects