13-kV rectifiers: studies on diodes and asymmetric thyristors

For rectifiers with high blocking voltages, the application of field stop layers reduces power losses. Preliminary experimental results are presented from asymmetric 13-kV thyristor samples based on a conventional field stop concept. By connecting a 13-kV diode in series to this asymmetric thyristor, a symmetrically-blocking tandem device can be built. Numerical studies show that the turn-off behavior of the 13-kV diode required for the tandem solution can be significantly improved by a new field stop concept based on an n layer buried in the weakly-doped region of the p⁺-n^--n⁺ power diode.