20 April 2011 Characterization of EUV resists for defectivity at 32nm
Author Affiliations +
Extreme ultraviolet (EUV) lithography is considered as the leading patterning technology beyond the ArF-based optical lithography, addressing the need for transistor densification to meet Moore's Law. Theoretically, EUV lithography at 13.5nm wavelength meets the resolution requirements for 1xnm technology nodes. However, there are several major challenges in the development of EUV lithography for mass production of advanced CMOS devices. These include the development of high power EUV light sources, EUV optics, EUV masks, EUV resists, overlay accuracy, and metrology and inspection capabilities. In particular, it is necessary to ensure that effective defect control schemes will be made available to reduce the EUV lithography defectivity to acceptable levels. This paper presents a study on the wafer defectivity and characterization of patterned EUV resists, with the objective of providing a quantitative comparison between the defectivity of different resist materials and different stacks. Patterned wafers were printed using the ASML® EUV full-field Alpha-Demo Tool (ADT 0.25 NA) at imec. The EUV resist patterns were 32nm line/spaces. Several advanced resist types were screened experimentally. The different resist types and stacks were inspected using a DUV laser based brightfield inspection tool, followed by a SEM defect review and CD metrology measurements. The patterns were characterized in terms of defect types and defect density. We identified the major defect types and discuss factors that affect the defectivity level and pattern quality, such as resist type, exposure dose and focus. Defect scattering analysis of DUV polarized light at different polarizations was performed, to indicate on the inspection performance trends for a variety of defect types and sizes of the different resists and stacks. The scattering analysis shows that higher defect scattering is induced using polarized light.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ofir Montal, Ofir Montal, Ido Dolev, Ido Dolev, Moshe Rosenzweig, Moshe Rosenzweig, Kfir Dotan, Kfir Dotan, Doron Meshulach, Doron Meshulach, Ofer Adan, Ofer Adan, Shimon Levi, Shimon Levi, Man-Ping Cai, Man-Ping Cai, Chris Bencher, Chris Bencher, Chris S. Ngai, Chris S. Ngai, Christiane Jehoul, Christiane Jehoul, Dieter Van Den Heuvel, Dieter Van Den Heuvel, Eric Hendrickx, Eric Hendrickx, } "Characterization of EUV resists for defectivity at 32nm", Proc. SPIE 7971, Metrology, Inspection, and Process Control for Microlithography XXV, 79710G (20 April 2011); doi: 10.1117/12.881323; https://doi.org/10.1117/12.881323

Back to Top