Patent ID: 6649487
Filing Date: 2003-11-18
Classification: H01L

Abstract:
A method of manufacturing a semiconductor integrated circuit device, comprising steps of:forming in a semiconductor substrate a first groove for trench isolation; depositing a first insulating film in said first groove and over a main surface of said substrate, said first insulating film having a thickness such that a cavity is formed in said first insulating film within said first groove and said cavity is enclosed within said first insulating film; removing said first insulating film to form a second groove in said first insulating film by leaving material of said first insulating film in said first groove, said second groove having a depth shallower than a depth of said first groove, and wherein after said removing said first insulating film to form said second groove said cavity remains enclosed within said first insulating film, under the second groove; and burying a second insulating film in said second groove so as to fill said second groove.