Study on overlay AEI-ADI shift on contact layer of advanced technology node
| Autor: | Qiang Wu, Weiming He, He Kaiting, Yi-Shih Lin, Yuntao Jiang, Guogui Deng, Lihong Xiao, Bin Xing, Jingan Hao, Qiang Zhang, Xuelong Shi, Chang Liu |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
business.industry Subtraction 02 engineering and technology Overlay 021001 nanoscience & nanotechnology 01 natural sciences 010309 optics Tilt (optics) Optics 0103 physical sciences Wafer Node (circuits) 0210 nano-technology business Telecommunications Focus (optics) Layer (electronics) Hard mask |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2220013 |
| Popis: | In this paper, we present a study on the overlay (OVL) shift issue in contact (CT) layer aligned to poly-silicon (short as poly) layer (prior layer) in an advanced technology node [1, 2]. We have showed the wafer level OVL AEI-ADI shift (AEI: After Etch Inspection; ADI: After Developing Inspection; AEI-ADI: AEI minus ADI). Within the shot level map, there exists a center-edge difference. The OVL focus subtraction map can well match the OVL AEI-ADI shift map. Investigation into this interesting correlation finally leads to the conclusion of PR tilt. The film stress of the thick hard mask is responsible for the PR tilt. The method of OVL focus subtraction can therefore be a powerful and convenient tool to represent the OVL mark profile. It is also important to take into account the film deposition when investigating OVL AEI-ADI shift. |
| Databáze: | OpenAIRE |
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