Novel Anionic Photoacid Generators (PAGs) and Corresponding PAG Bound Polymers

Summary: A new series of functionalized anionic photoacid generators (PAGs), and corresponding polymers were prepared in moderate to good yield and characterized. The thermostability of PAG bound polymers was superior to PAG blend polymers. The fluorine-free PAG bound or blend polymers exhibited higher stability than fluorine-substituted PAG bound or blend polymers. Although the acid generating efficiency of PAG blend polymers was higher than that of PAG bound polymers, yet it is anticipated that PAG incorporated into the polymer main chain may improve acid diffusion compared with the PAG blend polymers. This was demonstrated by preliminary electron beam lithography (EBL) results: the fluorine PAG bound polymer resist HE-F4-MBS-TPS gave 35 nm 1:1 L/S and showed better resolution than the blend sample HE Blend F4-IBBS-TPS. The PAG bound resist showed the capability for higher resolution, since 30 nm 2:1 L/S patterned. Based on these preliminary EBL results, the PAG bound polymer samples are anticipated to have a resolution capability for the 32 nm node for EUVL. Design of microstructures for EUV lithography.