Low dielectric constant SILK films as bottom antireflective coating layers for both KrF and ArF lithography

For advanced lithography processes, a BARC layer for patterning low dielectric materials is essential. Here we demonstrate new bottom antireflective coating (BARC) materials for both KrF and ArF lithography. The antireflective layer is composed of a low dielectric constant material SILK and its etching hard mask layer, such as an oxide or nitride film. The SILK is a commercial low dielectric material, which shows good etching and electrical characteristics. We report optical constants of the SILK film in the ultraviolet spectral region.