Emission of visible radiation from extended plasmas in silicon diodes during second breakdown

Thin film silicon-on-sapphire diodes have been reverse biased into second breakdown and the formation of a filament has been observed between the anode and cathode. This filamentary conduction was accompanied by emission of visible radiation, the light being much more intense than that associated with avalanche or microplasma emission. The filamentary emission appeared to be associated with both thermal heating of the diode to temperatures as hot as 600-800°C and the formation of a plasma. Quantum efficiencies as high as 0.04 percent have been observed and plasmas extending over anode-cathode spacings of up to 100 µm have been observed.