Synthesis and properties of new anionic photoacid generators bound polymer resists for e-beam and EUV lithography

A new series of methacrylate substituted benzene sulfonic photoacid generators (PAGs) and a perfluoro alkanesulfonic PAG, bound polymeric resists based on hydroxystyrene (HS) and 2-ethyl-2-adamantyl methacrylate (EA) were prepared and characterized. The acid yield of these PAG bound polymer resists was among the range of 54-81% under deep ultraviolet exposure (254 nm) that agrees well with the electron withdrawing effect of the substituents on the PAG anion for enhancing acid generation efficiency. The intrinsic lithography performance of these polymer-bound PAG resists showed sub-50 nm half-pitch resolution and < 5 nm LER (3 sigma).