Operation of a semiconductor opening switch at ultrahigh current densities

The operation of a semiconductor opening switch (SOS diode) at cutoff current densities of tens of kA/cm² is studied. In experiments, the maximum reverse current density reached 43 kA/cm² for ∼40 ns. Experimental data on SOS diodes with a p ⁺-p-n-n ⁺ structure and a p-n junction depth from 145 to 180 μm are presented. The dynamics of electron-hole plasma in the diode at pumping and current cutoff stages is studied by numerical simulation methods. It is shown that current cutoff is associated with the formation of an electric field region in a thin (∼45 μm) layer of the structure’s heavily doped p-region, in which the acceptor concentration exceeds 10¹⁶ cm⁻³, and the current cutoff process depends weakly on the p-n junction depth.