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 h ave been used to determine thickness, while the index of refraction an d other optical properties are often determined using conventional ell ipsometry. Commercial ellipsometers can be unreliable due to the low s urface reflectivity (<1%) of aerogel and xerogel films. A simple inter ferometric method, termed the polarized reflectance technique for thic kness and index, is used to simultaneously measure the index of refrac tion and thickness of thin aerogel and xerogel films of SiO2, TiO2, Zr O2, and composite materials with an accuracy of +/-0.5%. (C) 1998 Else vier Science B.V. All rights reserved.