Outlook for potential third-generation immersion fluids
2007
In a search for alkane candidates for 193 nm immersion fluids, several alkanes and cycloalkanes were synthesized,
purified and screened to ascertain their absorption at 193 nm, refractive index and temperature dispersion coefficient in
the context of the actual application. In general, cycloalkanes, and more specifically polycycloalkanes, possess a higher
refractive index than do linear alkanes. Decalin, cyclodecane, perhydrophenanthreme (PHP), perhydrofluorene (PHF)
and perhydropyrene (PHPY) are examined as potential second and third generation immersion fluids. The use of
perhydropyrene, which possesses a high refractive index of 1.7014 at 193 nm, may be limited as an immersion fluid
because of high absorption at 193 nm. Mixtures of cycloalkanes can lead to a higher enhancement of the refractive index
together with a decrease on the viscosity. Exhaustive purification of the fluids is a critical step in determining the real
absorption of the different fluids at 193 nm. Two simple purification processes of these cycloalkanes were developed
that led to low absorption fluids in the VUV region. The possibility of forming the oxygen complex in aerated fluids was
reduced by purging samples with argon or nitrogen. This easy elimination of the oxygen complex shows the weak
bonding nature of this complex.
Keywords:
- Correction
- Cite
- Save
- Machine Reading By IdeaReader
0
References
0
Citations
NaN
KQI