Patent ID: 6958525

Claim:
A semiconductor device comprising: a semiconductor substrate; a first film formed on a surface of said semiconductor substrate and made of a first silica-containing porous material; and a second film in direct contact with said first film and made of a second silica-containing porous material, the second silica-containing porous material having an etching rate different from an etching rate or the first silica-containing porous material under a same etching condition; wherein the first and second silica-containing porous materials contain siloxane resin expressed by a general chemical formula of: (R 10 to R 12 represent hydrogen, oxygen or a monovalent hydrocarbon group, n 1 represents an integer of 5 to 200, and X represents hydrogen or silicon), or: (R 13 to R 16 represent hydrogen, fluorine or a monovalent hydrocarbon group, n 2 is an integer of 5 to 100, wherein at least one of R 13 to R 16 is hydrogen); wherein for the first silica-containing porous material, at least one of R 10 to R 12 is a phenyl group or a hydrocarbon group having two to five carbon atoms, or at least one of R 13 to R 16 is a phenyl group or a hydrocarbon group having two to five carbon atoms, and for the second silica-containing porous material, none of R 10 to R 12 are a hydrocarbon group having two or more carbon atoms or none of R 13 to R 16 are a hydrocarbon group having two or more carbon atoms.