Patent ID: 6815280
Filing Date: 2004-11-09
Classification: H01L,Y10S

Abstract:
A method of manufacturing a semiconductor device, comprising:forming a gate insulating film in each of a region in which a first MOS transistor is to be formed and another region in which a second MOS transistor is to be formed on a semiconductor substrate; forming a film of a gate electrode material on the entire surface of said gate insulating film; forming said first film of a resist material on the entire surface of said gate electrode material; patterning said first film of said resist material in a manner to have a pattern of a size larger than a gate width of said gate electrode of at least said first MOS transistor in a region where said first MOS transistor is to be formed and to have a pattern conforming with a gate electrode of said second MOS transistor in a region in which said second MOS transistor is to be formed so as to form a first mask; selectively etching said film of said gate electrode material by an etching method using said first mask so as to form said gate electrode of said second MOS transistor; after removing said first mask, applying an oxidizing treatment so as to form a first gate post oxide film on a circumferential side wall of said gate electrode of at least said second MOS transistor; after forming a second film of a resist material on the entire surface of said regions where said first and second MOS transistors are to be formed, patterning said second film of said resist material in a manner to have a pattern conforming with said gate electrode of said first MOS transistor in a region where said first MOS transistor is to be formed and a pattern covering the entire surface in a region in which said second MOS transistor is to be formed so as to form a second mask; selectively etching said film of said gate electrode material by an etching method using said second mask so as to form said gate electrode of said first MOS transistor; and applying an oxidizing treatment so as to form a second gate post oxide film differing in thickness from said first gate post oxide film on a circumferential side wall of said gate electrode of said first MOS transistor in a region other than a region in which said first gate post oxide film is formed.