Quarter micron KrF excimer laser lithography

For quarter-micron KrF excimer laser lithography, a chemically amplified positive resist with high stability and process compatibility has been developed. 0.25- mu m line and space patterns and 0.35- mu m contact hole patterns have been obtained using this resist. The multiple interference effect due to reflection from air and substrate is reduced by using an overcoat film or antireflective coating. The overcoat film is made of a water-soluble polyvinylalcohol derivative. The refractive index of this polymer is 1.3, which is suitable for the resist (index