Semiconductor device having a reduced surface field strength

摘要

A semiconductor device of the "RESURF" type has a substrate region and a superimposed semiconductor layer which forms a p-n junction with the substrate region. The semiconductor layer has an island-shaped region which is depleted at least locally up to the surface at a reverse voltage applied across the p-n junction which is well below the breakdown voltage of the p-n junction. According to the invention the island-shaped part of the semiconductor layer over at least a part of its area has a doping profile in the vertical direction with at least two overlying layer portions with different average net doping concentrations and of the same or opposite conductivity type, so as to increase the current-carrying capacity of the semiconductor layer.