Resolution enhancement for lensless mask metrology with RESCAN

Iacopo Mochi; Uldis Locans; Atoosa Dejkameh; Ricarda Nebling; Dimitrios Kazazis; Li-Ting Tseng; Yasin Ekinci

doi:10.1117/12.2537068

Translator Disclaimer

29 September 2019 Resolution enhancement for lensless mask metrology with RESCAN

Iacopo Mochi, Uldis Locans, Atoosa Dejkameh, Ricarda Nebling, Dimitrios Kazazis, Li-Ting Tseng, Yasin Ekinci

Author Affiliations +

Proceedings Volume 11147, International Conference on Extreme Ultraviolet Lithography 2019; 111471D (2019) https://doi.org/10.1117/12.2537068
Event: SPIE Photomask Technology + EUV Lithography, 2019, Monterey, California, United States

Abstract

The EUV photomask is a key component of the lithography process for semiconductor manufacturing. A critical defect on the mask could be replicated on several wafers, causing a significant production yield reduction. For this reason, actinic patterned mask inspection is an important metrology component for EUV lithography. The RESCAN microscope is a lensless imaging platform dedicated to EUV mask defect inspection and metrology. The resolution of the tool is about 35 nm, which is similar to that of state-of-the-art EUV microscopes. To improve the resolution of RESCAN, we designed an upgraded optical layout for the illumination system and we developed a coherent diffraction imaging-compatible method to synthesize a custom pupil structure. This new scheme will enable a lensless EUV microscope with a resolution down to 20 nm and thereby allow mask review capabilities for future technology nodes with EUV lithography.

Citation Download Citation

Iacopo Mochi, Uldis Locans, Atoosa Dejkameh, Ricarda Nebling, Dimitrios Kazazis, Li-Ting Tseng, and Yasin Ekinci "Resolution enhancement for lensless mask metrology with RESCAN", Proc. SPIE 11147, International Conference on Extreme Ultraviolet Lithography 2019, 111471D (29 September 2019); https://doi.org/10.1117/12.2537068

ACCESS THE FULL ARTICLE