Metrology target design (MTD) solution for diagonally orientated DRAM layer
| Autor: | Hsueh-Jen Tsai, Chia-Hung Chen, Myungjun Lee, Kuo-Yao Chou, Mark D. Smith, Jo-Lan Chin, Jen-Chou Huang, Hao-Lun Huang, Chen Dror, Healthy Huang, Jui-Chin Yang, Yuan-Ku Lan, Michael E. Adel, Harvey Cheng, Jinyan Song, Tal Itzkovich, Ady Levy, Yaniv Abramovitz, Chin-Chang Huang, I-Lin Wang, Hsien-Yen Lung |
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| Rok vydání: | 2016 |
| Předmět: |
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Depth of focus Zernike polynomials Exit pupil business.industry Computer science 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Metrology 010309 optics symbols.namesake Optics 0103 physical sciences symbols Electronic engineering Process window Sensitivity (control systems) 0210 nano-technology business Lithography Dram |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| Popis: | We present a novel metrology target design framework using the scanner exit pupil wavefront analysis together with Zernike sensitivity analysis (ZSA) based on the Monte-Carlo technique. The proposed method enables the design of robust metrology targets that maximize target process window (PW) while minimizing placement error discrepancies with device features in the presence of spatial and temporal variation of the aberration characteristics of an exposure tool. Knowing the limitations of lithography systems, design constraints, and detailed lithography information including illumination, mask type, etc., we can successfully design an optimal metrology target. We have validated our new metrology target design (MTD) method for one of the challenging DRAM active layer consisting of diagonal line and space patterns illuminated by a rotated extreme dipole source. We find that an optimal MTD target gives the maximized PW and the strong device correlation, resulting in the dramatic improvement of overall overlay performance. The proposed target design framework is completely general and can be used to optimize targets for different lithography conditions. The results from our analysis are both physically sensible and in good agreement with experimental results. |
| Databáze: | OpenAIRE |
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