Enhanced Acid Diffusion Control by Using Photoacid Generator Bound Polymer Resist

Photoacid generators (PAGs) have been widely used as a key component for improving photoresist performance. The acid diffusion influences on the photoresist characteristics of resolution and line edge roughness (LER). The PAG bound polymer resist has been a key component for solving the problems of PAG aggregation and acid diffusion control. A triphenyl sulfonium salt methacrylate as PAG was synthesized and copolymerized with crosslinkable glycidyl methacrylate and methyl methacrylate by radical reaction for a new PAG bound polymer resist. The characterization of resist polymers was carried out by H-1 NMR. The lithographic performance of photoresists was investigated by ArF lithography. Both PAG bound resist and the PAG blended resist were employed to demonstrate the effect of PAG unit in a resist system. The polymer bound PAG resist improved the LEA and showed a higher resolution than the PAG blend resist.