Effects of photoacid generator incorporation into the polymer main chain on 193 nm chemically amplified resist behavior and lithographic performance

Abstract

The need for chemically amplified resists (CARs) that can resolve sub-65-nm node features with sufficient linewidth roughness (LWR) control and sensitivity to meet the requirements outlined in the International Technology Roadmap for Semiconductors has placed a significant and daunting challenge for the design of resist materials that can achieve these goals. In this article, the ability to improve the performance of CARs designed for 193 nm lithography via the direct bonding of a photoacid generator (PAG) anion into the resist polymer main chain has been investigated. The bound-PAG anion resist is shown to achieve higher sensitivity and resolution with smaller LWR than their blended-PAG resist analog. Binding of the PAG anion provides reduced photoacid diffusivity, higher maximum PAG loadings, and more homogeneous PAG distributions that help achieve these three critical resist requirements.