Patent ID: 7648869
Filing Date: 2010-01-19
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor structure in a substrate of semiconductor material, the method comprising: forming a first doped well in the semiconductor material of the substrate; forming a second doped well in the semiconductor material of the substrate proximate to the first doped well; forming a first trench with sidewalls extending in the semiconductor material of the substrate at a location between the first and second doped wells from a base toward a top surface of the substrate; forming a second trench having sidewalls extending between the first and second wells and between the sidewalls of the first trench and the top surface; at least partially filling the first trench with a material containing a mobile dopant; thermally diffusing the mobile dopant from the material into the semiconductor material adjacent to the sidewalls of the first trench and into the semiconductor material adjacent to the base of the first trench to define a buried conductive region having a higher dopant concentration than the first and second doped wells; and filling at least the second trench with a dielectric material.