Paper EW-WeA2
Real Time Film Thickness Monitoring on Roll to Roll Coaters

Wednesday, October 22, 2008, 3:40 pm, Room Exhibit Hall

Flexible substrates have been increasingly used to support deposition of thin films for packaging, pharmaceutical and solar industries where cost efficient production and consistent quality coatings are the drivers. Real time thickness monitoring of the deposited layers present several challenges such as mechanical alignment, unrolling speed of the substrate and complex material properties of the substrate, that need to be overcome in order to perform a successful measurement. HORIBA Jobin Yvon has developed an in-line configuration of its UVISEL spectroscopic ellipsometer that address the measurements difficulties encountered on a roll to roll coater. The UVISEL is capable of measuring a spectral range from 190 nm to 880 nm in just fifty milliseconds (50 ms) that makes it suitable for most rolling speed currently used. New fitting algorithms have been developed in order to characterize accurately complex substrate materials. Example of real time dielectric film thickness and optical constants deposited on moving Polyethylene Terephthalate (PET) and Aluminum (Al) flexible substrates are presented.