Low dielectric constant polymer materials as bottom antireflective coating layers for both KrF and ArF lithography

Abstract

In this paper, we demonstrate a new bottom antireflective coating (BARC) layer for both KrF and ArF lithography. The antireflective layers are composed of a novel low-dielectric constant polymer material (SiLK) and its etching hard-mask layer. By adding an optimized hard-mask layer, the reflectance of less than 1% at the resist/silicon substrate interface can be achieved. SiLK also has great potential to be used as BARC layers on various highly-reflectance substrates for metal-interconnect applications with large thickness-controlled tolerance. By using this novel structure, it is easy to reduce reflectance without adding an extra BARC layer for patterning low-dielectric materials. In this paper, suitable etching characteristics and thermal stability of SiLK-based BARC layers are also described.