Semiconductor device and manufacturing method of the same

A manufacturing method of a semiconductor device, comprising the steps of:

• subjecting a surface of a semiconductor substrate to element isolation to demarcate a first active region and a second active region;
• forming a first gate insulating film on the first active region and the second active region;
• fabricating the first gate insulating film and leaving the first gate insulating film in such a manner that an end portion fabricated of the first gate insulating film is located on any portion other than a first gate electrode forming region in the first active region and a second gate electrode forming region in the second active region;
• forming a second gate insulating film on the first active region and the second active region, including on the first gate insulating film;
• fabricating the second gate insulating film and leaving the second gate insulating film in such a manner that an end portion fabricated of the second gate insulating film overlaps the end portion fabricated of the first gate insulating film;
• simultaneously subjecting a surface of the first gate insulating film and a surface of the second gate insulating film to a surface recovery treatment;
• and
• pattern-forming a first gate electrode on the first gate electrode forming region with the first gate insulating film therebetween and a second gate electrode on the second gate electrode forming region with the second gate insulating film therebetween, respectively.