Patent ID: 7728403

Claim:
A semiconductor device having a source contact ( 1 ) and a drain contact ( 2 ) interconnected by a drift layer ( 3 ) doped by dopants according to a first conductivity type, n or p and in a conducting path between the source contact and the drain contact in a forward biased state of the device, on top of the drift layer ( 3 ), a plurality of metal layer regions ( 6 ) belonging to the source contact making Schottky-contacts to the drift layer ( 3 ) and being laterally separated by regions in the form of additional layers ( 7 , 7 ″) of semiconductor material doped by dopants according to a second conductivity type being opposite to said first type constituting pn-junctions at the interface thereof to the drift layer ( 3 ) and a continuous blocking pn-junction in the reverse biased state of the device shielding said Schottky-contact regions, said source contact on said additional layers, wherein at least one ( 7 ″) of said additional layers having a substantially larger lateral extension and area of the interface to the drift layer ( 3 ) than adjacent such layers ( 7 ), and each said additional layer ( 7 , 7 ″) is located on top of said drift layer ( 3 ) while forming an interface to said drift layer ( 3 ) laterally restricted by said Schottky-contact regions ( 6 ), with said metal layer regions ( 6 ) situated on a side of said additional layers ( 7 , 7 ″) opposite said drift layer ( 3 ) and also laterally bordering said additional layers ( 7 , 7 ″) and separating said additional layers ( 7 , 7 ″) from one another, such that said metal layer regions ( 6 ) completely border each said additional layer ( 7 , 7 ″) on all sides except a side on the drift layer ( 3 ).