Abstract

In deep ultraviolet lithographic tools, precise measurement of excimer laser pulse energy is essential. However, system noise of the energy sensor, which is used to monitor the laser pulse during exposure dose control, complicate pulse energy measurement. To improve measurement precision, a specific finite impulse response filter is proposed for signal denoising. Particularly, the convolution kernel of the specific finite impulse response filter is derived from the nonlinear fitting of the energy sensor output. Experimental results show that the measurement precision of the energy sensor improves 2–3 times with the specific finite impulse response filter. To verify the effectiveness of the energy sensor, it is used for transmittance measurement; the measurement result of a Corning 7980 witness sample is consistent with that measured by a commercial ultraviolet spectrophotometer and the measurement accuracy is 0.11% (k=2).

© 2017 Optical Society of America

Measurement of the frequency response of a diaphragm-based pressure sensor by use of a pulsed excimer laser

Fabin Shen, Juncheng Xu, and Anbo Wang
Opt. Lett. 30(15) 1935-1937 (2005)

Design of finite impulse response deconvolution filters

Richard Vollmerhausen
Appl. Opt. 49(30) 5814-5827 (2010)

Integrated optics implementation of finite impulse response filters

Emmanuel Anemogiannis and Richard P. Kenan
Appl. Opt. 29(24) 3497-3502 (1990)

Finite impulse response filter with large dynamic range and high sampling rate

D. M. Gooki and M. H. Berry
Appl. Opt. 29(8) 1061-1062 (1990)

Particle swarm optimization-based approach for optical finite impulse response filter design

Ying Zhou, Guangjie Zeng, and Feihong Yu
Appl. Opt. 42(8) 1503-1507 (2003)