Influence of buffer structures on static and dynamic ruggedness of high voltage FWDs

It is required to design free wheeling diodes (FWDs) to be robust against static and dynamic avalanche. Therefore we investigate the effect of different buffer structures and the influence of various bulk parameters. By numerical device simulation the effect of the buffer doping, base doping and base width on the static and dynamic behaviour of FWDs is analysed. We show the promising features of well designed buffers for ruggedness and their coherences to the static reverse characteristics.