Patent ID: 8378445

Claim:
A semiconductor structure comprising: a semiconductor substrate of a first conductivity; an epitaxial layer of a second conductivity on the substrate; a buried layer of the second conductivity interposed between the substrate and the epitaxial layer; a first trench structure extending through the epitaxial layer and the buried layer to the substrate, the first trench structure including a first sidewall insulation and a first conductive material in electrical contact with the substrate at a bottom of the first trench structure; a second trench structure extending through the epitaxial layer to the buried layer, the second trench structure including a second sidewall insulation and a second conductive material in electrical contact with the buried layer at a bottom of the second trench structure; and a region of insulating material laterally extending from the conductive material of the first trench structure to the conductive material of the second trench structure and longitudinally extending to a substantial depth of the second trench structure.