11 May 2009 Reticle inspection-based critical dimension uniformity
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Proceedings Volume 7379, Photomask and Next-Generation Lithography Mask Technology XVI; 73791D (2009) https://doi.org/10.1117/12.824319
Event: Photomask and NGL Mask Technology XVI, 2009, Yokohama, Japan
Non-uniformity in reticle CDs can cause yield loss and/or performance degradation during chip manufacturing. As a result, CD Uniformity (CDU) across a reticle is a very important specification for photomask manufacturing. In addition the photomask CDU data can be used in a feedback loop to improve and optimize the mask manufacturing process. A typical application is utilizing CDU data to adjust the mask writer dose and compensate for non-uniformity in the CDs, resulting in improved quality of subsequent masks. Mask makers are currently using the CD-SEM for data collection. While the resolution of SEM data ensures its position as the industry standard, an output map of CDU using the reticle inspection tool has the advantage of denser sampling over larger areas on the mask. High NA reticle inspection systems scan the entire reticle at high throughput, and are ideally suited for collecting CDU data on a dense grid. In this paper, we describe the basic theory of a prototype reticle inspection-based CDU tool, and results on advanced memory masks. We discuss possible applications of CDU maps for optimizing the mask manufacturing process or in adjusting scanner dose to improve wafer CD uniformity.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Venu Vellanki, Venu Vellanki, Carl Hess, Carl Hess, Gang Pan, Gang Pan, Chunlin Chen, Chunlin Chen, Gregg Inderhees, Gregg Inderhees, Daniel Lopez, Daniel Lopez, "Reticle inspection-based critical dimension uniformity", Proc. SPIE 7379, Photomask and Next-Generation Lithography Mask Technology XVI, 73791D (11 May 2009); doi: 10.1117/12.824319; https://doi.org/10.1117/12.824319

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