2-WAVELENGTH ANTIREFLECTION COATING FOR ARF EXCIMER-LASER LITHOGRAPHYOPTICS

Citation
Js. Kim et al., 2-WAVELENGTH ANTIREFLECTION COATING FOR ARF EXCIMER-LASER LITHOGRAPHYOPTICS, Journal of the Korean Physical Society, 33(2), 1998, pp. 136-142
Citations number
17
Categorie Soggetti
Physics
ISSN journal
03744884
Volume
33
Issue
2
Year of publication
1998
Pages
136 - 142
Database
ISI
SICI code
0374-4884(1998)33:2<136:2ACFAE>2.0.ZU;2-G
Abstract
In ArF excimer laser lithography optics, two wavelengths are used for different purposes. One is for exposure, and the other is for through- the-lens alignment. Hence, we studied an anti-reflection coating funct ioning at two wavelengths simultaneously. At first, 2- and 3-layer die lectric thin-films were designed just for the exposure wavelength (lam bda=193 nm), and the performance analysis and optimization of the refl ectance at the alignment wavelength (lambda=488 nm) followed. The tran smittance dependency on the incident angle was analyzed at both wavele ngths. The uniformity of the transmittance in lithography optics over the range of incident angles is as important as low reflectance in att aining uniform intensity distribution in the exposure field. The best of our designs was the [air/CaF2/LaF3/BaF2/substrate] structure, consi dering the deposition errors. This design showed uniform transmittance and low reflectance over the range of +/-30 degrees for the incident angles.