Measurement precision improvement for excimer laser pulse energy sensor based on a special finite impulse response filter

Xie, Chengke, Chen, Ming, Zhu, Jing, Yang, Baoxi, Huang, Huijie

Publication in Journal of Optical Technology

For Russian citation (Opticheskii Zhurnal):

Chengke Xie, Ming Chen, Jing Zhu, Baoxi Yang, Huijie Huang Measurement precision improvement for excimer laser pulse energy sensor based on a special finite impulse response filter (Улучшение точности измерений датчика энергии импульсов излучения эксимерного лазера на основе специального фильтра импульсного отклика с конечной длительностью) [на англ. яз.] // Оптический журнал. 2017. Т. 84. № 5. С. 75–79.

Chengke Xie, Ming Chen, Jing Zhu, Baoxi Yang, Huijie Huang Measurement precision improvement for excimer laser pulse energy sensor based on a special finite impulse response filter (Улучшение точности измерений датчика энергии импульсов излучения эксимерного лазера на основе специального фильтра импульсного отклика с конечной длительностью) [in English] // Opticheskii Zhurnal. 2017. V. 84. № 5. P. 75–79.

For citation (Journal of Optical Technology):

Chengke Xie, Ming Chen, Jing Zhu, Baoxi Yang, and Huijie Huang, "Measurement precision improvement for excimer laser pulse energy sensor based on a special finite impulse response filter," Journal of Optical Technology. 84(5), 346-349 (2017). https://doi.org/10.1364/JOT.84.000346

Abstract:

In deep ultraviolet lithographic tools, precise measurement of excimer laser pulse energy is essential. However, system noises of the energy sensor, which is used to monitor 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 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).

Keywords:

photolithography, excimer lasers, detectors, optical standards and testing, metrology, transmission

OCIS codes: 110.5220; 140.2180; 250.0040; 120.4800; 120.3940; 120.7000

References:

1. Postnikov S., Hector S., Garza C., Peters R, Ivin V. Critical dimension control in optical lithography // Microelectronic Eng. 2003. V. 69. P. 452–458.
2. Kivenzor G. and Zimmerman R. Dose metrology for DUV lithographic tools // Proc. SPIE. 2001. V. 4404. P. 368–371.
3. Tracy D.H., Wu F.Y. Exposure dose control techniques for excimer laser lithography // Proc. SPIE. 1988. V. 922. P. 437–443.
4. Guo L., Huang H., Wang X., and Zhang D. Exposure dose control for step-and-scan lithography // Proc. SPIE. 2005. V. 5645. P. 217–222.
5. Liu S., Wu X. Real-time exposure dose control algorithm for DUV excimer lasers // Acta Optica Sinica (in Chinese). 2011. V. 26. P. 878–884.
6. Hu C. Design and verification of FIR filter based on Matlab and DSP // Proc. Intern. Conf. Image Analysis and Signal Processing (IASP). 2012.
7. Chen X. and Koenders L. A novel pitch evaluation of one-dimensional gratings based on a cross-correlation filter // Meas. Sci. Technol. 2014. V. 25. P. 044007.
8. Diaz-Ramirez V.H., Picos K., and Kober V. Target tracking in nonuniform illumination conditions using locally adaptive correlation filters // Opt. Commun. 2014. V. 323. P. 32–43.
9. Xu P., Miao Q., Tang X., and Zhang J. A denoising algorithm via wiener filtering in the shearlet domain // Multimed Tools Appl. 2014. V. 71. P. 1529–1558.
10. Zhao S., Shmaliy Y.S., Liu F. Fast computation of discrete optimal FIR estimates in white Gaussian noise // IEEE Signal Process. Lett. 2015. V. 22. P. 718–722.