19 May 2011 RegC: a new registration control process for photomasks after pattern generation
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Proceedings Volume 8081, Photomask and Next-Generation Lithography Mask Technology XVIII; 80810V (2011) https://doi.org/10.1117/12.899904
Event: Photomask and NGL Mask Technology XVIII, 2011, Yokohama, Japan
As the lithography roadmap unfolds on its path towards ever smaller geometries, the pattern placement (Registration) requirements are increasing dramatically. This trend is further enhanced by anticipating the impact of innovative process solutions as double patterning where mask to mask overlay on the wafer is heavily influenced by mask registration error. In previous work1 a laser based registration control (RegC) process in the mask periphery (outside the exposure field) was presented. While providing a fast and effective improvement of registration, the limitation of writing with the laser outside of the active area limits the registration improvement to ~25%. The periphery process can be applied after the pattern generation or after pellicle mounting and allows fine tuning of the mask registration. In this work we will show registration correction results where the full mask area is being processed. While processing inside the exposure field it is required to maintain the CD Uniformity (CDU) neutral .In order to maintain the CDU neutral several different laser writing steps are utilized. A special algorithm and software were developed in order to compute the process steps required for maintaining the CDU neutral from one side while correcting for mask placement errors on the other side. By applying the correction process inside the active area improvements of up to 50% of the 3S registration and values as low as 3 nm 3S after scale and ortho correction have been achieved. These registration improvements have been achieved while maintaining the CDU signature of the mask as measured by areal imaging with WLCDTM (Wafer Level CD Metrology tool from Carl Zeiss SMS).
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Erez Graitzer, Erez Graitzer, Guy Ben-Zvi, Guy Ben-Zvi, Avi Cohen, Avi Cohen, Dmitriev Vladimir, Dmitriev Vladimir, Dan Avizemer, Dan Avizemer, } "RegC: a new registration control process for photomasks after pattern generation", Proc. SPIE 8081, Photomask and Next-Generation Lithography Mask Technology XVIII, 80810V (19 May 2011); doi: 10.1117/12.899904; https://doi.org/10.1117/12.899904

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