DEEP N WELLS IN TRIPLE WELL STRUCTURES AND METHOD FOR FABRICATING SAME

摘要

A disclosed method for fabricating a structure in a semiconductor die comprises steps of implanting a deep N well (240) in a substrate, depositing an epitaxial layer over the substrate, and forming a P well (242) and a lateral isolation N well (246) over the deep N well, wherein the lateral isolation N well laterally surrounds the P well, and wherein the deep N well and the lateral isolation N well electrically isolate the P well. Implanting a deep N well can comprise steps of depositing a screen oxide layer over the substrate, forming a mask over the screen oxide layer, implanting the deep N well in the substrate, removing the mask, and removing the screen oxide layer. Depositing the epitaxial layer can comprise depositing a single crystal silicon over the substrate.