Successful fluids for use in 3rd generation 193 nm immersion lithography must have refractive indices of ≥ 1.80 at
193 nm, ≤ 0.15/cm absorbance at 193 nm, and be photochemically inert to 193 nm radiation. Various classes of organic
compounds were prepared and evaluated for use as 3rd generation 193 nm immersion fluids. Functional groups that were
evaluated included: sulfones, sulfoxides, sulfonic acids, ammonium sulfonate salts, alkanes, alkyl chlorides, alkynes,
and nitriles. Several compounds were synthesized including three sulfone and three sulfonic acid compounds. Other
commercially available compounds of interest underwent extensive purification prior to evaluation. Although this work
did not lead to any specific solutions to the challenge of identifying 3rd generation 193 nm immersion fluids, it can be
concluded that high density hydrocarbons based on cubane may have the best chance of meeting these goals.