Patent ID: 7329583
Filing Date: 2008-02-12
Classification: H01L

Abstract:
1. A process of fabricating a semiconductor device comprising: providing a semiconductor substrate of a first conductivity type, the substrate not containing an epitaxial layer; forming a first mask on a surface of the substrate, said first mask having a first opening defining a location of a first deep layer in a lateral dimension; implanting a dopant of a second conductivity type through the first opening to form the first deep layer; forming a second mask on the surface of the substrate, said second mask having a second opening defining a location of a second deep layer in the lateral dimension, a width of the second opening being less that a width of the first opening; and implanting dopant of the first conductivity type through the second opening to form the second deep layer, wherein the projected range of the implant of dopant of the first conductivity type is less than the projected range of the implant of dopant of the second conductivity type such that the second deep layer overlaps and extends above the first deep layer.