1 August 2002 Pellicle-induced distortions in advanced photomasks
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Proceedings Volume 4754, Photomask and Next-Generation Lithography Mask Technology IX; (2002) https://doi.org/10.1117/12.476974
Event: Photomask and Next Generation Lithography Mask Technology IX, 2002, Yokohama, Japan
A comprehensive design of experiment was elaborated to evaluate the effects of frame flatness, mask adhesive compliance, and mounting load on pellicle-induced distortions for soft pellicle systems. A dynamic mechanical analyzer was used to determine the elastic modulus of the adhesives materials, and a capacitive sensor-based tool was employed to measure the pellicle frame bow prior to mounting. Registration measurements were conducted on test reticles on a 21 X 21 array of grid points, before and after pellicle attachment. Statistical analysis (Anova test) was conducted to determine if the means for each sample group were statistically discernable. Overall, the magnitude of the distortions was very low for the pellicle mounting mechanism selected. Nevertheless the results indicated that the sample group with the flexible (softer) mask adhesive material exhibited lower distortions than that with conventional (stiffer) mask adhesive. Either larger sample size and/or wider variations in initial frame bow and mounting pressure will be required to assess the impact of these parameters on pellicle-induced distortions. Flexible (softer) mask adhesives are believed to minimize photomask deformation during the mounting process, resulting in lower pellicle-induced distortions.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Minoru Fujita, Minoru Fujita, Masaya Akiyama, Masaya Akiyama, Masahiro Kondo, Masahiro Kondo, Hiroaki Nakagawa, Hiroaki Nakagawa, Daniel Tanzil, Daniel Tanzil, Florence O. Eschbach, Florence O. Eschbach, Eric P. Cotte, Eric P. Cotte, Roxann L. Engelstad, Roxann L. Engelstad, Edward G. Lovell, Edward G. Lovell, "Pellicle-induced distortions in advanced photomasks", Proc. SPIE 4754, Photomask and Next-Generation Lithography Mask Technology IX, (1 August 2002); doi: 10.1117/12.476974; https://doi.org/10.1117/12.476974

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