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 1H 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 LER and showed a higher resolution than the PAG blend resist.

A photoacid generator (PAG) is a component of chemical amplification photoresists (CAR). The most widely used PAG in CAR system is triphenyl onium salt which is well known to one of the best leaving groups from various radiation. Acid diffusion influences resist characteristics in area such as resolution and linewidth control. The structure of the hydrophilic PAG was designed to restrict acid diffusion within the photoresist. Acid amplification was suppressed by the hydroxyl group-acid interaction. Novel PAGs with functional groups were synthesized and characterized. Poly(GMA-co-MMA) was synthesized with a combination of crosslinkable glycidyl methacrylate (GMA) and highly refractive methyl methacrylate (MMA). The synthesized polymers were confirmed by NMR and FT-IR, and their thermal properties were studied using TGA and DSC. The resists were evaluated as a positive type resist for ArF lithography. PAGs exhibited good acid generation efficiency with controlled acid diffusion. We found that the energy latitude property of the photoresist was improved with hydroxyl-PAG.