Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
849934 | Optik - International Journal for Light and Electron Optics | 2013 | 5 Pages |
Abstract
Partial coherence (generally represented by σ) is one of the important parameters of lithographic tool to assess the performance of pupil fill. In this paper, a novel method of partial coherence measurement for the illumination system is proposed. Statistical results of measured σ by the proposed method are analyzed. The dependence of partial coherence on the defocus, which is the distance from the measuring position to the best image plane, is also investigated. The simulation results prove the effectiveness of this method, and with the defocus increasing, the measured partial coherence decreases. Generally, if three times of the standard deviation is required to be 1 × 10−3, the amount of defocus should be less than 96 μm.
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Physical Sciences and Engineering
Engineering
Engineering (General)
Authors
Ai-Ping Zhai, Yi-Ping Cao, Bin Chen, Dongmei Cai, Hongye Wei,