SOPRA produces a Spectroscopic Ellipsometer capable to work down to 135 nm.
The entire spectral range is 135-650 nm. This enable to measure all the new
materials designed for the next generation lithography (157 nm, Fe excimer laser),
like photoresist, ARC layers and all the optics included in the next generation
Stepper.
Based on GES5E platform, the ellipsometer works into a purged glove box to
reduce the oxygen and water contamination in the part per million ranges. Dry
Nitrogen is injected continuously in the box with automatic adjustment of the
surpressure. One working face with three gloves allows mounting the sample (up
to 200 mm diameter) on the sample holder. The optical set up includes a premonochromator
in the polarizer arm to avoid photo resist bleaching.
In addition to ellipsometry, the system can make photometric measurements at
fixed polarization state ( reflectance and transmittance) . Scatterometric measurements
are also possible.