Novel 193nm Photoresist Based on Olefin-Containing Lactones

摘要

In this work we have studied new types of olefin-containing alicyclic lactones such as α-angelicalactone(AGL), γ-methylene- γ-butyrolactone(γ-MBL), α-methylene- γ-butyrolactone(α-MBL) and their derivatives. Particular attention was given to α-MBL derivatives, which are readily synthesized. The relative monomer reactivities of the various lactones were found to be quite different. However in the case of α-MBL and its derivatives they have good radical reactivities with methacrylates and maleic anhydride. Methacrylate derivatives with acid-labile protecting groups were introduced for dissolution contrast. To further promote adhesion the relative ratios of maleic anhydride and norbornylene derivatives was optimized. These novel resists resolve 120nm L/S with conventional illumination (NA=0.6, σ=0.7) and 0.6μm DOF with annular illumination(NA=0.6, σ=0.6/0.8). And also 100nm L/S resolution was achieved using strong off-axis illumination. Oxide etch resistance was found to be equivalent to acetal based KrF resists. Post exposure delay (PED) stability of more than 1 hour was achieved.