Error analysis of overlay compensation methodologies and proposed functional tolerances for EUV photomask flatness
| Autor: | Christopher Lee, Thomas J. Dunn, Katherine Ballman, Alexander Timothy Bean |
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| Rok vydání: | 2016 |
| Předmět: |
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Engineering drawing Engineering business.industry Flatness (systems theory) Extreme ultraviolet lithography 02 engineering and technology Overlay 021001 nanoscience & nanotechnology 01 natural sciences Metrology 010309 optics 0103 physical sciences Reticle Electronic engineering Photomask 0210 nano-technology business Lithography |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2242282 |
| Popis: | Due to the impact on image placement and overlay errors inherent in all reflective lithography systems, EUV reticles will need to adhere to flatness specifications below 10nm for 2018 production. These single value metrics are near impossible to meet using current tooling infrastructure (current state of the art reticles report P-V flatness ~60nm). In order to focus innovation on areas which lack capability for flatness compensation or correction, this paper redefines flatness metrics as being “correctable” vs. “non-correctable” based on the surface topography’s contributions to the final IP budget at wafer, as well as whether data driven corrections (write compensation or at scanner) are available for the reticle’s specific shape. To better understand and define the limitations of write compensation and scanner corrections, an error budget for processes contributing to these two methods is presented. Photomask flatness measurement tools are now targeting 6σ reproducibility |
| Databáze: | OpenAIRE |
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