Make The Impossible Possible: Use Variable-Shaped Beam Mask Writers And Curvilinear Full-Chip Inverse Lithography Technology For 193i Contacts/Vias With Mask-Wafer Co-Optimization

A review of the benefits and mask time and quality for a full-chip, curvilinear, stitchless ILT with MWCO for VSB mask writers on 193i process wafer prints.



“Full-chip curvilinear inverse lithography technology (ILT) requires mask writers to write full reticle curvilinear mask patterns in a reasonable write time. We jointly study and present the benefits of a full-chip, curvilinear, stitchless ILT with mask-wafer co-optimization (MWCO) for variable-shaped beam (VSB) mask writers and validate its benefits on mask and wafer at Micron Technology. The full-chip ILT technology employed, first demonstrated in a paper presented at the 2019 SPIE Photomask Technology Conference, produces curvilinear ILT mask patterns without stitching errors, and with process windows enlarged by over 100% compared to the OPC process of record, while the mask was written by multibeam mask writer. At the 2020 SPIE Advanced Lithography Conference, a method was introduced in which MWCO is performed during ILT optimization. This approach enables curvilinear ILT for 193i masks to be written on VSB mask writers within a practical, 12-h time frame, while also producing the largest process windows. We first review MWCO technology, then curvilinear ILT mask patterns written by VSB mask writer, and then show the corresponding 193i process wafer prints. Evaluations of mask write times and mask quality in terms of critical dimension uniformity and process windows are also presented.”

Find the technical paper here. Published February 2024.

Pang, Linyong, Sha Lu, Ezequiel Vidal Russell, Yang Lu, Michael Lee, Jennefir Digaum, Ming-Chuan Yang et al. “Make the impossible possible: use variable-shaped beam mask writers and curvilinear full-chip inverse lithography technology for 193i contacts/vias with mask-wafer co-optimization.” Journal of Micro/Nanopatterning, Materials, and Metrology 23, no. 1 (2024): 011207-011207.

Author Affiliations: D2S Inc. and Micron Technology Inc.

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