Theoretical model of the SOS effect

This paper describes physical principles underlying operation of semiconductor opening switches (SOS). The SOS effect occurs at a current density of up to 60 kA/cm² in silicon p⁺-p-n-n⁺ structures filled with residual electron-hole plasma [1]. Using a theoretical model developed for plasma dynamic calculations, the mechanism by which current passes through the structure at the stage of high conduction and the processes that take place at the stage of current interruption were analyzed. The dynamics of the processes taking place in the structure was calculated with allowance for both diffusive and drift mechanisms of carrier transport. In addition, two recombination types, viz., recombination via impurities and impact Auger recombination, were at the basis of the model The effect of the structure on the pumping-circuit current and voltage was also taken into account. The real distribution of the doped impurity in the structure and the avalanche mechanism of carriers multiplication were considered. The results of calculations of a typical SOS are presented. The dynamics of the electron-hole plasma is analyzed. It is shown that the SOS effect represents a qualitatively new mechanism of current interruption in semiconductor structures.