Patent ID: 7897464
Filing Date: 2011-03-01
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device including a buried insulating film formed in a bottom part of a trench and a buried-type gate electrode formed in the trench, the method comprising: selectively forming an insulating film in the bottom part of the trench such that a side wall of the trench is not covered by the insulating film; forming a mask having an opening in a part that corresponds to a region where a device isolation insulating film is formed on a surface of a semiconductor substrate after forming the insulating film, the mask including an oxide film and a nitride film; and oxidizing the surface of the semiconductor substrate in the opening to form the device isolation insulating film, wherein the step of oxidizing the surface of the semiconductor substrate in the opening to form the device isolation insulating film is performed after the step of selectively forming the insulating film in the bottom part of the trench.