IMMERSION LITHOGRAPHIC COMPOSITION FOR FORMING UPPER FILM AND METHOD FOR FORMING PHOTORESIST PATTERN

摘要

An upper layer-forming composition formed on a photoresist while causing almost no intermixing with the photoresist film and a photoresist patterning method are provided. The upper layer-forming composition is stably maintained without being eluted in a medium such as water during liquid immersion lithography and is easily dissolved in an alkaline developer. The upper layer-forming composition covers a photoresist film for forming a pattern by exposure to radiation. The composition comprises a resin dissolvable in a developer for the photoresist film and a solvent in which the resin is dissolved. The solvent has a viscosity of less than 5.2 x 10-3 Pa·s at 20°C. In addition, the solvent does not cause intermixing of the photoresist film and the upper layer-forming composition. The solvent contains an ether or a hydrocarbon.