An effective and practical control technology of critical dimensions for submicron VSLI is presented. An ARCOR (anti- reflective coating on resist) process was improved, which is applied as a transparent type anti-reflective coating. A water soluble and low refractive index film was developed for this purpose. The following five items were measured experimentally and discussed: (1) amplitude of swing curve's dependence on resist thickness, (2) thickness latitude of the ARCOR film, (3) photo speed, (4) CD variations in a submicron DRAM, and (5) alignment accuracy with a bright field alignment system.
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