The FR-Pro-UV/VIS optical film thickness measurement system is based on Reflected White Light Spectroscopy over a wavelength range of 220 - 850m nm.
The reflected spectrum is complared to a baseline reference spectrum from bare Silicon, and fitted to a model spectrum of the film stack thicnesses and material composition. A library of models for thin films of dielectrics, polymers, resists, semiconductors, metals, etc. is installed.
Wafers and substrates can be mapped by automated measurements using a motorised stage convering a movement range of 100 x 100 mm.
It is also possible to do automated measurements of arbitrary points from a coordinate list with mapped registration, using 3 alignment marks on the wafer.