Optical polarized reflectance characterization of thin aerogel and xerogel films

Advancement of porous dielectric materials like aerogels and xerogels for thin film devices demands sample characterization. Profilometers have been used to determine thickness, while the index of refraction and other optical properties are often determined using conventional ellipsometry. Commercial ellipsometers can be unreliable due to the low surface reflectivity (<1%) of aerogel and xerogel films. A simple interferometric method, termed the polarized reflectance technique for thickness and index, is used to simultaneously measure the index of refraction and thickness of thin aerogel and xerogel films of SiO2, TiO2, ZrO2, and composite materials with an accuracy of +/-0.5%. (C) 1998 Elsevier Science B.V. All rights reserved.