Paper
24 July 2018 Tolerance analysis of hyper numerical aperture lithography objective with freeform surfaces
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Proceedings Volume 10827, Sixth International Conference on Optical and Photonic Engineering (icOPEN 2018); 108272C (2018) https://doi.org/10.1117/12.2501037
Event: Sixth International Conference on Optical and Photonic Engineering (icOPEN 2018), 2018, Shanghai, China
Abstract
To ensure the good performance of hyper-numerical-aperture (NA) freeform surfaces lithography objective, not only the aberration should be decreased as much as possible in theory design stage, but also all the tolerances should be allocated reasonably and controlled rigorously in the manufacturing process. Therefore, reasonable tolerance analysis for projection objective is needed to maximally make up for the image quality deterioration caused by manufacture and assembly errors. According to the variation sensitivity between Zernike aberration and the single tolerance, effective compensators for individual aberrations can be chosen during tolerance analysis. As an example the method is applied to the tolerance analysis for an NA1.2 catadioptric projection objective with freeform surfaces designed by us. The results show that, after tolerance analysis using the compensators selected by this method, the root mean square (RMS) wavefront error of the projection objective is less than 0.015λ (λ=193 nm) at 90% probability, which meets the image quality requirement of lithographic projection objective for 10 nm technology node.
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Shanshan Mao, Yanqiu Li, Meng Zheng, Ke Liu, and Lihui Liu "Tolerance analysis of hyper numerical aperture lithography objective with freeform surfaces", Proc. SPIE 10827, Sixth International Conference on Optical and Photonic Engineering (icOPEN 2018), 108272C (24 July 2018); https://doi.org/10.1117/12.2501037
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KEYWORDS
Tolerancing

Lithography

Wavefronts

Monochromatic aberrations

Image quality

Distortion

Objectives

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