| Autor: |
Wim de Boeij, Bart van Bussel, Young Ha Kim, Wim Bouman, Young Seog Kang, Roelof de Graaf, Jong Hoon Jang, AJ Arij Rijke, Chansam Chang, Richard Droste, Patrick Neefs, Jeong-Heung Kong, ByeongSoo Lee, Stefan Weichselbaum |
| Rok vydání: |
2016 |
| Předmět: |
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| Zdroj: |
SPIE Proceedings. |
| ISSN: |
0277-786X |
| DOI: |
10.1117/12.2220588 |
| Popis: |
Adjustment and control of the illumination pupil asymmetry is relevant for wafer alignment and overlay of lithography tools. Pupil asymmetries can cause a tilt in aerial image (Aerial Image Tilt, or AIT). This AIT, combined with a focus offset, leads to a horizontal image shift. Pupil asymmetries can be related to a shift of the entire illumination pupil (geometrical telecentricity) caused by illuminator misalign. Another type of pupil asymmetry is energetic imbalance (quantified by pupil Center of Gravity, COG). The scanner can show pupil variation across the exposure slit. In general the COG at the edge of the slit is often worse than in the center part of the slit. Recently, ASML has released the NXT:1980Di that is equipped with an enhanced illuminator to improve pupil COG variation across the slit. In this paper we explore the performance of this scanner system and show that the AIT variation across the slit is also reduced significantly. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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