Patent ID: 7416987
Filing Date: 2008-08-26
Classification: H01L

Abstract:
1. A semiconductor device fabrication method, comprising: forming a first insulating film by chemical vapor deposition, on a surface of a semiconductor substrate having a trench in a surface portion, thereby covering inner walls of the trench with the first insulating film; forming a second insulating film by coating, on the first insulating film on the trench; and etching back the second insulating film to leave a lower portion of the second insulating film over a bottom of the trench and to remove a remaining portion of the second insulating film, wherein, when the second insulating film is etched back by the etching, the etching rate of the first insulating film is lower than that of the second insulating film, thereby allowing a portion of the first insulating film to remain over the bottom of the trench.