US Patent 7772344 Insulating film-forming composition

It is an object of the present invention to provide a composition capable of forming an insulating film which is endowed with a low dielectric constant, heat resistance, chemical resistance and a high mechanical strength that enables the insulating film to withstand CMP, and which, when an inorganic insulating film layer is provided thereon as an overlying layer, has a high adherence thereto. The composition for forming an insulating film contains polyphenylene, wherein the polyphenylene in an insulating film formed from the composition has a number of carbon atoms (C) and a number of oxygen atoms (O) which together satisfy a condition O/(C+O)≧0.050. With the composition, the above object is attained.