This paper describes the lithographic properties of fifteen acid amplifiers (AAs) and the chemical modeling
approach used to predict their thermal stability in an ESCAP polymer resist system at 70 and 110 °C. Specifically, we
show how added AAs affect the sensitivity (Eo and Esize), resolution, line edge roughness (LER), exposure latitude, and
Z-parameter of ESCAP resists. We find that acid amplifiers that generate fluorinated sulfonic acids give the best
combination of sensitivity, LER, and exposure latitude. Additionally, we show that these compounds are not
photochemically active. Combining thermodynamic and kinetic modeling has allowed us to predict the relative enthalpies of activation for catalyzed and uncatalyzed decomposition pathways and compare the results to experimental
thermal stability tests.
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.