23 March 2006 Resolution improvement of EPL stencil mask using thin membrane
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Electron Projection Lithography (EPL) provides a fundamental advantage in resolution. In this paper, resolution improvement of EPL masks and minimum resolution in EPL exposure are addressed. In order to improve the mask resolution, we applied membranes thinner than typical thickness of 2 um to e-beam scattering layers of the EPL stencil masks. Although strength of the membrane generally deteriorates with decrease in the membrane thickness, the EPL masks having 1-um-thick scattering layers were feasibly fabricated. Reduction of the membrane thickness down to 1 um considerably improved the mask minimum feature size to resolve 120-nm holes and 80-nm lines which corresponded to 30 nm and 20 nm on wafer dimension, respectively, in the 4x demagnification EPL exposure system. The application of the 1-um-thick membrane simultaneously brought the high resolution and good pattern qualities: CD uniformity less than 10 nm in 3σ with pattern sidewall angle range of 90° ± 0.2°. We performed wafer exposure experiments in combination of the EPL exposure tool NSR-EB1A (Nikon) and the 1-um-thick membrane mask, and obtained the resolution performance of 40-nm holes on the wafer. We conclude that the application of the 1-um-thick membrane to the e-beam CD qualities. The exposure resolution of 40-nm holes on the wafer reveals the EPL exposure system to be a potential solution for contact layers in the future technology node.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hiroshi Sugimura, Hiroshi Sugimura, Hideyuki Eguchi, Hideyuki Eguchi, Masashi Norimoto, Masashi Norimoto, Yoshiyuki Negishi, Yoshiyuki Negishi, Isao Yonekura, Isao Yonekura, Kojiro Ito, Kojiro Ito, Akira Tamura, Akira Tamura, Fumihiro Koba, Fumihiro Koba, Hiroshi Arimoto, Hiroshi Arimoto, } "Resolution improvement of EPL stencil mask using thin membrane", Proc. SPIE 6151, Emerging Lithographic Technologies X, 61511F (23 March 2006); doi: 10.1117/12.655425; https://doi.org/10.1117/12.655425


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