Mos device with isolated drain and method for fabricating the same

Abstract

A method for fabricating a metal-oxide-semiconductor (MOS) device with isolated drain. The method performing operations of: forming a first well region embedded in a portion of a semiconductor substrate; forming a first patterned mask layer over the semiconductor substrate, exposing portions of the semiconductor substrate; performing a first ion implant process on the portions of the semiconductor substrate exposed by the first patterned mask layer; performing a second ion implant process to a second well region exposed, forming a fourth well region between the first well region and the second well region; performing a third implant process to the second well region, forming a fifth well region overlying the fourth well region; forming a source region in a portion of the third well region; and forming a drain region in a portion of the fifth well region.