Latest developments in photosensitive developable bottom anti-reflective coating (DBARC)

Abstract

Developable bottom anti-reflective coatings (DBARC) are an emerging litho material technology. The biggest advantage of DBARC is that it eliminates the plasma etch step, avoiding damage to plasma sensitive layers during implantation. AZ has pioneered developable BARC based on photosensitive cleave as well as crosslink/decrosslink mechanisms. In this paper, we focus on the crosslink/decrosslink concept. DBARC/resist mismatching was corrected both from process and formulation sides. The optimized DBARC showed comparable lithographic performance as conventional BARCs. This paper provides the chemical concept of the photosensitive developable DBARCs, approaches for DBARC/resist matching and performance of photosensitive DBARCs for 248 nm and 193 nm exposures. Recent 193 nm immersion exposure results are also presented.