Fluoride Glasses for 193 nm Optics
- 1 December 1996
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 35 (12S)
- https://doi.org/10.1143/jjap.35.6351
Abstract
Aluminum fluoride based fluoride glasses were evaluated in comparison with silica glass for their potential for use in 193 nm lithography optics. A pure fluoride glass and fluoride glasses containing a small amout of phosphate exhibit UV absorption edges shorter than that of silica glass. Their reflection spectra in the vacuum UV region also indicate that they have wider band gaps than silica glass, suggesting that they are promising materials for 193 nm optics. However, strong induced absorption in the UV region was observed under ArF excimer laser exposure, of which the absorption bands were attributed to photo-induced oxidation of Fe2+ to Fe3+ and formation of electron trapped centers on [ PO4] groups. It is important to keep the contents of both transition metal impurities and phosphate as low as possible in fluoride glasses intended for use in 193 nm lithography optics.Keywords
This publication has 5 references indexed in Scilit:
- OH Content Dependence of the Intensity of ArF-Excimer-Laser Induced Absorption in Synthetic Fused Silica.The Review of Laser Engineering, 1995
- High-performance glass for the deep ultraviolet rangeJournal of Non-Crystalline Solids, 1994
- Radiation effects in glassesNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1992
- Reflection Spectra of Fluorozirconate Glass on the Extreme Ultraviolet RegionMaterials Science Forum, 1985
- Fundamental defect centers in glass: Electron spin resonance and optical absorption studies of irradiated phosphorus-doped silica glass and optical fibersJournal of Applied Physics, 1983