Patent ID: 7820551
Filing Date: 2010-10-26
Classification: H01L

Abstract:
1. A manufacturing method of a semiconductor device comprising: forming a line-form insulating film on a main surface of a semiconductor substrate; etching the semiconductor substrate with the line-form insulating film used as a mask to form two adjacent first trenches on both sides of the line-form insulating film; forming side wall insulating films on respective side walls of the adjacent first trenches; etching the semiconductor substrate with the line-form insulating film and side wall insulating films used as a mask to form second trenches in bottom portions of the adjacent first trenches; oxidizing the semiconductor substrate with the line-form insulating film and side wall insulating films used as an anti-oxidation mask to cause oxide regions formed on adjacent side walls of the second trenches lying on both sides of the semiconductor substrate to make contact with each other; removing the line-form insulating film and side wall insulating films; forming a gate insulating film on a surface of a semiconductor region of the semiconductor substrate which is exposed by removing the line-form insulating film and the side wall insulating films; forming a gate electrode on the gate insulating film; and forming a fin field effect transistor having the semiconductor region as a line-form fin.