Field Shielded Anode (FSA) concept enabling higher temperature operation of fast recovery diodes

In this paper, we introduce the Field Shielded Anode (FSA) concept that enables higher temperature operation of fast recovery diodes with planar junction termination. Conventional diodes utilizing local lifetime control principles show excellent dynamic properties at the expense of a higher leakage current, which is generated during reverse blocking when the space charge region penetrates into the zone containing the radiation defects. In contrast to this, the FSA concept spatially separates the space charge region from the zone with the radiation defects. The ruggedness of conventional diodes can be exceeded with the new FSA concept, while the leakage current is reduced by a factor of ~4. This was achieved using a special junction extension introduced between the active area and the guard-ring termination. The design parameters and their influence on the softness and the safe-operating area are presented.