7 May 2013 High-order aberration measurement technique based on a quadratic Zernike model with optimized source
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Abstract
In this paper, we propose an aberration metrology (AM) of a lithographic projection lens based on aerial images (AI) by using a quadratic relationship model (Quad) between the aerial-image intensity distribution and the Zernike coefficients. The proposed method (AMAI-Quad) uses principal component analysis and multiple linear regression analyses for model generation. The quadratic model is, then, used to extract Zernike coefficients by a nonlinear least-squares minimizing technique. The best linear constrain condition is estimated by optimizing the illumination settings. Compared with earlier techniques, based on a linear relationship between Zernike coefficients and AIs, the new method can extend the orders of Zernike coefficients measured. The application of AMAI-Quad to AIs, computed by lithography simulators PROLITH and Dr.LiTHO, demonstrated an extension of measurement range to 90mλ and an enhancement of measurement accuracy by more than 30 percent.
© 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)
Jishuo Yang, Jishuo Yang, Xiangzhao Wang, Xiangzhao Wang, Sikun Li, Sikun Li, Lifeng Duan, Lifeng Duan, Guanyong Yan, Guanyong Yan, Dongbo Xu, Dongbo Xu, Anatoly Y. Bourov, Anatoly Y. Bourov, Andreas Erdmann, Andreas Erdmann, } "High-order aberration measurement technique based on a quadratic Zernike model with optimized source," Optical Engineering 52(5), 053603 (7 May 2013). https://doi.org/10.1117/1.OE.52.5.053603 . Submission:
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