@inproceedings{09ac8f904cb4494c9a6d945a12d8fad7,
title = "Homogeneity improvement of TiO2-SiO2 glass synthesized by the soot method and its evaluation using the ultrasonic measurement system",
abstract = "TiO2-SiO2 glass is one of the leading candidates for optical elements of extreme ultraviolet lithography. TiO2-SiO 2 glass synthesized by the soot method has shown striae related to inhomogeneity of TiO2 concentration formed in the planes perpendicular to soot growth direction in the synthesis process. It can induce CTE variation and localized surface roughness. Striae were characterized in three modes by polarization microscope. Such striae were improved with an improved gas condition and developing a modified material gas supply system. Specimen prepared from the improved TiO2-SiO2 glass was evaluated by a line-focus-beam ultrasonic material characterization system, using a surfaceacoustic- wave mode. Improved glass had 43% striae level compared to conventional glass by birefringence measurement, 31% compared to conventional glass by the ultrasonic measurement. It was found that improved glass had good homogeneity to both directions perpendicular and parallel to striae plane.",
keywords = "EUVL, Homogeneity, Leaky surface acoustic waves, Line-focus-beam ultrasonic material characterization system, Optical material, Soot method, Striae, TiO-SiO glass",
author = "Masahiro Kawagishi and Junko Konishi and Masaaki Takata and Mototaka Arakawa and Yuji Ohashi and Kushibiki, {Jun Ichi}",
year = "2013",
doi = "10.1117/12.2011655",
language = "English",
isbn = "9780819494610",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Extreme Ultraviolet (EUV) Lithography IV",
note = "Extreme Ultraviolet (EUV) Lithography IV ; Conference date: 25-02-2013 Through 28-02-2013",
}