Patent ID: 7498619
Filing Date: 2009-03-03
Classification: H01L

Abstract:
1. A power electronic device of the multi-drain type integrated on a semiconductor substrate of a first type of conductivity comprising a plurality of elemental units, each elemental unit comprising: a body region of a second type of conductivity realized on a first semiconductor layer of the first type of conductivity formed on said semiconductor substrate, a column region of the second type of conductivity realized in an underlying second semiconductor layer below said body region, wherein said second semiconductor layer comprises at least three sub-semiconductor layers, overlapped on each other, wherein the resistivity of each sub-semiconductor layer is different from that of the other sub-semiconductor layers and said resistivity decreases in each sub-semiconductor layer upwards towards the first semiconductor layer, and wherein said column region comprises at least three doped sub-regions, each one realized in one of said sub-semiconductor layers, wherein the amount of charge of each doped sub-region balances the amount of charge of the sub-semiconductor layer in which each doped sub-region is realized and doping concentration increases in each doped sub-region upwards towards the first semiconductor layer.