28 June 2005 Improved cycle time of mask repair by optimizing nanomachining with photolithographic imaging simulation
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Proceedings Volume 5853, Photomask and Next-Generation Lithography Mask Technology XII; (2005) https://doi.org/10.1117/12.617346
Event: Photomask and Next Generation Lithography Mask Technology XII, 2005, Yokohama, Japan
Current generation photomasks use optical enhancements such as phase shifting and aggressive OPC in an effort to maintain image contrast as CDs shrink. The result is non-intuitive complex shapes with jogs and multiple levels with different materials. The mask repair engineer is challenged to work with defects that occur in ever tightening spaces on these complex masks. Prior established nanomachining technology allows nanometer level control of material removal. To date, the challenge in developing repair strategies that will meet transmission specifications as well as maintaining aerial image contrast through focus has been mainly an empirical exercise where the mask repair is attempted and aerial image measurement among other tests are used to verify the result. This approach can be streamlined by the use of lithography simulation which rigorously models the effects of mask defects on the aerial image at the wafer. Once the topography of the defect is measured by the nanomachining mask repair tool, lithography simulation can be proactively used to develop a repair strategy for the nanomachining process. Following this repair, the simulation software can then provide immediate feedback to confirm the post repair 3-D topology from AFM surface measurements for either approval or immediate rework. This integration is initially validated using a significant set of repairs with subsequent aerial image measurements compared to some of the more common evaluative analyses.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Peter Brooker, Peter Brooker, Tod Robinson, Tod Robinson, John Lewellen, John Lewellen, Bob Naber, Bob Naber, Ron Bozak, Ron Bozak, David A. Lee, David A. Lee, } "Improved cycle time of mask repair by optimizing nanomachining with photolithographic imaging simulation", Proc. SPIE 5853, Photomask and Next-Generation Lithography Mask Technology XII, (28 June 2005); doi: 10.1117/12.617346; https://doi.org/10.1117/12.617346

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