Flashover development process across silicon and surface microcosmic phenomena induced by pulsed voltage in air

We report the flashover development phenomenon across a polished silicon wafer and its damage effect on the silicon surface under pulsed excitation of similar to 0.4/2.5 mu s with a peak value of > 6 kV in atmospheric air. A visible light channel connecting two electrodes is observed before the complete flashover occurs. The filament and pit - jut damages induced by the flashover are found on the silicon surface. A comprehensive flashover development hypothesis is proposed according to which first the filamentary current process occurs in the surface layer of a semiconductor and then the ionization process of air ambient above the surface occurs. The observed surface damages are considered to be closely correlated with the two processes.