26 March 2007 On the quality of measured optical aberration coefficients using phase wheel monitor
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In-situ aberration measurement often requires indirect methods that retrieve the pupil phase from the measured images and presents unique challenges to the engineers involved. Phase wheel monitor allows such in-situ measurement of aberrations in photolithography systems. The projection lens aberrations may be obtained with high accuracy from images of phase wheel targets printed in photoresist. As a result, the photolithography tool optics can be characterized under standard wafer printing conditions. Resulting features are mathematically analyzed to extract information about the aberrations in optics. We use a detection algorithm and multi-domain modeling to process resist images and determine the image deviation from the ideal shape, which in turn allow the amount of aberration introduced by the optical system to be quantified. Experimental results are shown and multiple measurements on the same tool before and after system corrections are compared.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lena V. Zavyalova, Lena V. Zavyalova, Aaron R. Robinson, Aaron R. Robinson, Anatoly Bourov, Anatoly Bourov, Neal V. Lafferty, Neal V. Lafferty, Bruce W. Smith, Bruce W. Smith, } "On the quality of measured optical aberration coefficients using phase wheel monitor", Proc. SPIE 6520, Optical Microlithography XX, 65203T (26 March 2007); doi: 10.1117/12.721311; https://doi.org/10.1117/12.721311

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