Patent ID: 8309425

Claim:
A method of manufacturing a semiconductor device, comprising: preparing a semiconductor substrate having a first region and a second region other than the first region; forming a first mask over the first region, the first mask having a first line-and-space pattern extending in a first direction; performing a first removing process that selectively removes the first region with the first mask to form a first groove extending in the first direction, the first removing process removing an upper part of the second region while a remaining part of the second region having a first surface facing upward, and the bottom level of the first groove being higher than the level of the first surface; forming a first insulating film over the semiconductor substrate, the first insulating film comprising first and second portions, the first portion filling up the first groove, and the second portion covering the second region; removing the second portion and a part of the first portion while a remaining part of the first portion filling a bottom portion of the first groove; forming a second insulating film over the semiconductor substrate, the second insulating film filling up the first groove; and partially removing the second insulating film to make the top level of the second insulating film being equal to the top level of the semiconductor substrate.