Patent ID: 6927158

Claim:
A wiring forming method in a semiconductor device, the method comprising the steps of: (A) forming a wiring and a filling layer filled between wirings, on a substrate; (B) forming a gas permeable film on the wiring and the filling layer, said gas permeable film being made of a porous insulation material; (C) removing the filling layer through the gas permeable film so as to form a gap between the wirings; (D) filling the gap with a gas having a thermal conductivity equal to or higher than three times that of air at 0° C. through the gas permeable film into the gap; and (E) forming a gas impermeable film on the gas permeable film, wherein, the filling layer comprises: a non-fluorine system polymer selected from the group consisting of BCB, poly-aryl-ether, polyimide, and like effective non-fluorine system polymers, a fluorine system polymer selected from the group consisting of a fluorine addition polymer, tetra-fluoro ethylene, cyclo-perfluoro carbon, poly-aryl-fluoride ether, fluorine addition parylene, and like effective flourine system polymers, organic SOG, silicon oxide system xerogel, nano-porous silica, or amorphous carbon.