US Patent 7998663 Pattern formation method

After forming an underlying layer film and an intermediate layer film are formed over a substrate, a resist pattern formed by first pattern exposure using a first resist film and second pattern exposure using a second resist film is transferred onto the intermediate layer film. Furthermore, the underlying layer film is etched using the intermediate layer pattern as a mask, thereby obtaining an underlying layer film pattern. The underlying layer film includes as an adduct a fluorine-based surfactant or inorganic nano particles and is provided with a resistance against oxygen-based plasma.