Patent ID: 7750429
Filing Date: 2010-07-06
Classification: H01L

Abstract:
1. A semiconductor structure comprising: a pair of substantially vertical first trench sidewalls extending from a top surface of a semiconductor substrate to a first depth; a substantially horizontal first trench bottom surface having a first width and located at said first depth from said top surface and adjoined to said pair of substantially vertical first trench sidewalls; a first isolation trench structure comprising a dielectric material, wherein said dielectric material laterally abuts a semiconductor material in said semiconductor substrate throughout an entirety of an interface at said pair of substantially vertical first trench sidewalls between said top surface and said substantially horizontal first trench bottom surface at said first depth; a pair of substantially vertical second trench sidewalls extending from said top surface to a second depth, wherein said first depth is greater than said second depth; a substantially horizontal second trench bottom surface having a second width and located at said second depth from said top surface and adjoined to said pair of substantially vertical second trench sidewalls, wherein said first width is greater than said second width; and a p-well and an n-well on opposing sides of the first isolation trench structure, wherein an interface between the p-well and the n-well adjoins said substantially horizontal first trench bottom surface and is self-aligned to the middle of said substantially horizontal first trench bottom surface.