Patent ID: 6638804
Filing Date: 2003-10-28
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device, in which both a high-breakdown-voltage MOS transistor and a low-breakdown-voltage MOS transistor having different drain breakdown voltages are formed on an identical semiconductor substrate, the manufacturing method comprising the steps of:(a) forming a gate electrode on a first dielectric film created above the substrate; (b) forming a side wall on a side face of the gate electrode; and (c) implanting an impurity to define a drain area and a source area, wherein the step (b) comprises the sub-steps of: (b-1) creating a second dielectric film on surface of the substrate including the gate electrode; (b-2) forming a first mask, which covers a specific area corresponding to the high-breakdown-voltage MOS transistor; and (b-3) using the first mask and etching the second dielectric film, which is located on a certain area corresponding to the low-breakdown-voltage MOS transistor, out of the dielectric films created on the substrate, so as to form the side wall of the second dielectric film on the side face of the gate electrode in the low-breakdown-voltage MOS transistor.