157-nm coherent light source for F/sub 2/ laser lithography [spectrpmeter calibration]

Author

Suganuma, T. ; Kubo, H. ; Wakabayashi, O. ; Mizoguchi, H. ; Nakao, K. ; Nabekawa, Y. ; Togashi, T. ; Watanabe, S.

Author_Institution

Dept. of Equip. Technol. Res., Hiratsuka Res. Center, Kanagawa, Japan

fYear

2001

fDate

11-11 May 2001

Abstract

Summary form only given. F/sub 2/ lasers are taken notice of the light source for lithographic tools enabling structures below the 70 nm technology node. The F/sub 2/ laser linewidth is essential for the design of the lithography projection system. A dioptric design system requires the F/sub 2/ laser linewidth of about 0.2 pm (FWHM), which is due to the large dispersion of the refractive index of CaF/sub 2/ at 157 nm. Therefore the spectral measurement of a line-narrowed F/sub 2/ laser is very important. We have developed a 157 nm coherent light source (157CLS) to calibrate a VUV spectrometer. The 157CLS is required to have a very narrow linewidth, which can be approximated by a /spl delta/ function to a VUV spectrometer. This light source can also be used to inspect the optical systems by interferometry.

Keywords

calibration; multiwave mixing; optical harmonic generation; spectroscopic light sources; two-photon processes; ultraviolet lithography; ultraviolet spectrometers; 157 nm; VUV spectrometer calibration; coherent light source; dioptric design system; excimer laser lithography; frequency-tripled beam; second harmonics; single-mode Ti:sapphire oscillators; three-mirror confocal cavity; very narrow linewidth; Bandwidth; Laser theory; Light sources; Lithography; Nonlinear optics; Optical amplifiers; Optical design; Oscillators; Power generation; Spectroscopy;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics, 2001. CLEO '01. Technical Digest. Summaries of papers presented at the Conference on

Conference_Location

Baltimore, MD, USA

Print_ISBN

1-55752-662-1

Type

conf

DOI

10.1109/CLEO.2001.948225

Filename

948225