Trench structures in direct contact

摘要

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