New high transparent resist and process technology for KrF excimer laser lithography

Novel, very simplified, high-aspect-ratio, single-layer resist materials and process technology for KrF excimer laser lithography have been developed. They consist of a negative resist, a positive resist, and a surface treatment process called HARD (high-aspect-ratio resist pattern fabrication by alkaline surface disposal). Both the negative and positive resists are composed of an alkaline-soluble styrene polymer as the highly transparent main polymer. The HARD process differs from the conventional process only in the addition of an alkaline treatment of the resist surface before exposure. High-aspect-ratio resist patterns with a large focus latitude were obtained using this simple method. It is concluded that these techniques are an effective and simple way to fabricate deep-submicron-design-rule VLSIs.<
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