Multi-wavelength approach towards on-product overlay accuracy and robustness
| Autor: | Guo-Tsai Huang, John Lin, Christophe Fouquet, Kevin Cheng, Eason Su, Arie Jeffrey Den Boef, Benny Gosali, Ken Chang, Marc Noot, Kai-Hsiung Chen, Kaustuve Bhattacharyya, Hammer Chang, Cathy Wang, Sax Liao |
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| Rok vydání: | 2018 |
| Předmět: |
Diffraction
Accuracy and precision Boosting (machine learning) 02 engineering and technology Overlay 021001 nanoscience & nanotechnology 01 natural sciences 010309 optics Wavelength Stack (abstract data type) Robustness (computer science) 0103 physical sciences Electronic engineering Performance indicator 0210 nano-technology |
| Zdroj: | Metrology, Inspection, and Process Control for Microlithography XXXII. |
| Popis: | Success of diffraction-based overlay (DBO) technique1,4,5 in the industry is not just for its good precision and low toolinduced shift, but also for the measurement accuracy2 and robustness that DBO can provide. Significant efforts are put in to capitalize on the potential that DBO has to address measurement accuracy and robustness. Introduction of many measurement wavelength choices (continuous wavelength) in DBO is one of the key new capabilities in this area. Along with the continuous choice of wavelengths, the algorithms (fueled by swing-curve physics) on how to use these wavelengths are of high importance for a robust recipe setup that can avoid the impact from process stack variations (symmetric as well as asymmetric). All these are discussed. Moreover, another aspect of boosting measurement accuracy and robustness is discussed that deploys the capability to combine overlay measurement data from multiple wavelength measurements. The goal is to provide a method to make overlay measurements immune from process stack variations and also to report health KPIs for every measurement. By combining measurements from multiple wavelengths, a final overlay measurement is generated. The results show a significant benefit in accuracy and robustness against process stack variation. These results are supported by both measurement data as well as simulation from many product stacks. |
| Databáze: | OpenAIRE |
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