Patent ID: 7098153

Claim:
A method of manufacturing a semiconductor device, comprising steps of: forming a silicon oxynitride film on a surface of a semiconductor substrate; forming a conductive film for a gate electrode on the silicon oxynitride film; patterning the conductive film to leave a gate electrode; and implanting impurities into semiconductor regions on both sides of the gate electrode to form source and drain regions, wherein in the step of forming the silicon oxynitride film, the silicon oxynitride film is formed under the conditions that an existence ratio of subject nitrogen atoms to a total number of nitrogen atoms in the silicon oxynitride film becomes 20% or smaller and wherein three bonds of each subject nitrogen atom are all coupled to silicon atoms and remaining three bonds of each of three silicon atoms connected to the subject nitrogen atom are all coupled to other nitrogen atoms; and, wherein the silicon oxynitride film has a thickness of 3 nm or less.