There is provided a resist underlayer film for lithography causing no intermixing with a photoresist and having a dry etching rate higher than that of the photoresist, and a resist underlayer film forming composition for forming the underlayer film. In a first embodiment a coil of sliders is fed to an insertor mechanism for applying the slider downstream of a coil of zipper. A ruthenium based precursor, which includes ruthenium tetroxide dissolved in a mixture of at least two non-flammable fluorinated solvents, is provided and a ruthenium containing film is produced on the substrate. The resulting filtered graft polyol dispersion mainly has particles of 25 microns or smaller and is stable under a variety of conditions for at least 9 weeks. The etch stop layer is between the source and drain electrodes, and the source and drain electrodes are spaced apart from the etch stop layer.