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.

Date Published: 15 April 2008
PDF: 10 pages
Proc. SPIE 6923, Advances in Resist Materials and Processing Technology XXV, 69231O (15 April 2008); doi: 10.1117/12.772994

Published in SPIE Proceedings Vol. 6923:
Advances in Resist Materials and Processing Technology XXV
Clifford L. Henderson, Editor(s)