Characterization of MDM Optical Filters Using Ellipsometry

Indianapolis, IN

This research demonstrates the use of ellipsometry as a tool for detailed, non-invasive optical characterization. Alternating layers of chromium and dielectric (SiO₂) were grown on a silicon substrate with an electron beam evaporator. The resulting structures are deigned to be optical filters which would reflect a bandwidth of light centered on a certain wavelength. Number of layers and their thickness directly affect the width and the center wavelength of the reflectance band. We plan to show how ellipsometry and complementary AFM measurements can result in a much more detailed description of the films. We will also present details about various alternatives and the balances one has to strike between physically feasible and reasonably complex structures that can be modeled to represent the structure of the chromium/dielectric boundary.