Method for forming an interlayer insulating film, and semiconductor device

摘要

A method for forming an interlayer insulating film is disclosed. This method comprises the steps of: forming an underlying insulating film on an object to be formed; and forming a porous SiO2 film on said underlying insulating film by a Chemical Vapor Deposition that employs a source gas containing TEOS (tetraethoxy silane) and O3 where the O3 is contained in the source gas with first concentration that is lower than concentration necessary for oxidizing the TEOS.Alternative method for forming an interlayer insulating film is also disclosed. This method comprises the step of: forming an underlying insulating film on an object to be formed; performing Cl (chlorine) plasma treatment for the underlying insulating film; and forming a porous SiO2 film on the underlying insulating film by a Chemical Vapor Deposition that employs a source gas containing TEOS (tetraethoxy silane) and O3.