Patent ID: 8026558

Claim:
A semiconductor power device comprising: a plurality of groups of stripe-shaped trenches extending in a silicon region over a substrate; a contiguous sinker trench completely surrounding each group of the plurality of stripe-shaped trenches so as to isolate the plurality of groups of stripe-shaped trenches from one another, the contiguous sinker trench extending from a top surface of the silicon region through the silicon region and terminating with in the substrate, the contiguous sinker trench being wider and extending deeper than the plurality of stripe-shape trenches, the contiguous sinker trench being lined with an insulator only along the sinker trench sidewalls so that a conductive material filling the contiguous sinker trench makes electrical contact with the substrate along the bottom of the contiguous sinker trench and makes electrical contact with an interconnect layer along the top of the contiguous sinker trench.