Patent ID: 7754513
Filing Date: 2010-07-13
Classification: H01L

Abstract:
1. A method of forming a semiconductor structure using a semiconductor-on-insulator substrate having a semiconductor layer, a bulk semiconductor region of a first conductivity type underlying the semiconductor layer, and an insulating layer between the semiconductor layer and the bulk semiconductor region, the method comprising: forming an opening having sidewalls extending from a top surface of the semiconductor layer through the semiconductor layer and the insulating layer to a base intersecting the bulk semiconductor region; forming a conductive region of a second conductivity type opposite to the first conductivity type and disposed in the bulk semiconductor region proximate to the base of the opening; partially filling the opening with a first epitaxial layer of a semiconductor material epitaxially grown toward the top surface from the base of the opening and doped with the first conductivity type at a first doping concentration; and filling a remaining open space inside the opening to the top surface with a second epitaxial layer of the semiconductor material epitaxially grown toward the top surface of the opening from the first epitaxial layer and doped with the first conductivity type at a second doping concentration lower than the first doping concentration or doped with the second conductivity type.