US Patent 10090409 Method for fabricating LDMOS with self-aligned body

A method for fabricating a LDMOS device, including: forming a semiconductor substrate; forming a dielectric layer atop the semiconductor substrate and an electric conducting layer on the dielectric layer; forming a first photoresist layer on the electric conducting layer; patterning the first photoresist layer through a first mask to form a first opening; etching the electric conducting layer through the first opening; implanting dopants of a first doping type into the semiconductor substrate through the first opening to form a first body region adjacent to the surface of the semiconductor substrate, and a second body region located beneath the first body region; removing the first photoresist layer; etching the electric conducting layer using a second photoresist layer and a second mask.