An oral presentation entitled „In-line thickness and composition monitoring of deposited coatings in a roll-to-roll process tool by spectroscopic ellipsometry” will be held at LOPE-C conference (5th International Conference and Exhibition for the Organic and Printed Electronics Indistry) in Munich, Germany on 12th June, 2013 at 11:50 am. It will introduce Semilab’s newest ellipsometer development offered for in situ monitoring of coating thickness for roll-to-roll foil process.

Immediate determination of film uniformity and homogeneity are important factors for in situ coating quality process control. Spectroscopic ellipsometry (SE) as a measurement method ensures fast and reliable measurement required by characterization of thin film coatings on thin foil substrates. Semilab’s novel R2R SE metrology platform offers multi layer thickness and refractive index determination directly after the coating process on a moving roll-to-roll foil on-the-fly with acquisition time less than 100 ms per point.

The ellipsometer is measuring an approximately 500 μm optically focused spot area along the line determined by the roll progression. Synchronization of measurement locations is performed by a CCD camera observing the bar codes periodically printed on the foil, and by the external encoder trigger signal in between the barcodes for enhanced precision.

A key point in realizing the fast and accurate analysis of multilayer coatings is the feed forward functionality in the evaluation. During the process, the foil is measured after each deposited layer in the same synchronized locations, using the analysis results obtained previously. This enables sequential (step-by-step) evaluation of only one layer at a time, without the need of performing the full stack analysis.