Patent ID: 6946335

Claim:
A method of manufacturing an improved double-diffused metal-oxide-semiconductor with a self-aligned channel, comprising the following sequential steps: providing a substrate, and forming a silicon layer of a first type doping as a drain; oxidizing the surface of said silicon layer to form a field oxide layer; forming a vertical opening on said field oxide layer; then forming a screen oxide layer on the bottom of said vertical opening; forming a first spacer, which has a first opening with a specified width, over said vertical opening; forming a body of a second type doping and a second body of the second type doping with further higher concentration, below the bottom of said screen oxide layer; then removing said first spacer; forming a second spacer, which has a second opening with a width larger than that of said first opening, over said screen oxide layer; forming a source of the first type doping in the region neighboring said body, said second body and said second opening; then completely removing said second spacer and said screen oxide layer; then forming a gate oxide contacting said source, wherein said gate oxide is positioned in both lateral sides of said vertical opening's bottom; and lastly forming a step-like gate conductive layer over said gate oxide and said field oxide layer; then forming an insulating layer to shield said gate conductive layer and said gate oxide; finally depositing a source conductive layer.