P‐124: Methods of Measuring Thin Film Thickness on Polymer Substrate

Abstract

In this paper two methods of measuring the thickness of a thin film layer on polymer substrate are presented. The first one is based on a polarizing microscope and analyzing the interference spectrum of white light reflected by the specimen. The second is a microscope with a high numerical aperture lens. The interference fringes caused by the birefringence of the polymer substrate can be eliminated, and by a numerical procedure the film index and thickness can be extracted from the measured reflection spectrum. As an example, we made measurements on a single layer UV glue thin film coated on a polymer substrate, polyethylene terephthalate (PET) in this case. We used the Fourier Transform method to analyze the spectrum and confirmed the effect of these methods.

Current Opportunities and Challenges in Biopolymer Thin Film Analysis—Determination of Film Thickness

“…Sarfus is a setup where an optical microscope in crosspolarization mode is used in conjunction with specific substrates, so called surfs. The surfs consist of a silicon substrate with a top coating that does not polarize light on reflection and therefore leads to a signal enhancement of the film attached to that layer (Chiang and Yang, 2011). In combination with the use of a calibration standard, layer thicknesses down to 0.3 nm can be determined.…”