Low-dielectric constant FLARE 2.0 films for bottom antireflective coating layers in KrF lithography

In this paper, we demonstrate a new bottom-antireflective coating (BARC) layer for KrF lithography. The antireflective layer is composed of a commercial low-dielectric constant FLARE 2.0-based film. By adding an optimized etching hard-mask layer, reflectance of less than 3% at the resist/silicon substrate interface can be achieved. FLARE 2.0 films also have great potential to be used as BARC layers on highly reflective substrates for metal interconnect applications. It is easy to reduce reflectance without adding an extra BARC layer for patterning low-dielectric materials. It is convenient to use this novel BARC structure in KrF lithography. In this paper, suitable etching characteristics of FLARE 2.0-based BARC layers are also described.