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Design of photoresists with reduced environmental impact. 1: Water-soluble resists based on photo-cross-linking of poly(vinyl alcohol)

Journal Article · · Chemistry of Materials
DOI:https://doi.org/10.1021/cm980603y· OSTI ID:338386
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  1. Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
  2. Univ. of Texas, Austin, TX (United States). Dept. of Chemistry
  3. SEMATECH, Austin, TX (United States)

Various approaches to environmentally improved photoresist materials have been reported in the literature. The feasibility of a chemically amplified fully water-soluble negative-tone resist based upon the cross-linking of a poly(vinyl alcohol) (PVA) matrix resin has been demonstrated. Two-component resists incorporating PVA and (2,4-dihydroxyphenyl)dimethylsulfonium triflate as a water-soluble photoacid generator were formulated in deionized water and spin-coated onto bare silicon wafers. Negative-tone images were obtained upon irradiation at 254 nm, postbaking, and subsequent development in pure water. The two-component resist suffered from swelling during development, but improved performance was obtained through the addition of a cross-linking agent, hexamethoxymethylmelamine (HMMM). The resulting three-component, water-soluble resist was able to resolve micron-sized images using a 248 nm stepper, at a dose of ca. 200 mJ/cm{sup 2}. Model studies conducted using {sup 13}C NMR monitoring with 2,4-pentanediol as a model for PVA showed that under acidic catalysis HMMM reacts to form active electrophilic species that add to the diol, affording ether linkages with concomitant liberation of methanol.

OSTI ID:
338386
Journal Information:
Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 3 Vol. 11; ISSN CMATEX; ISSN 0897-4756
Country of Publication:
United States
Language:
English