Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013 · 30 citations · 2 references
Natural SciencesMaterials ScienceDiagnostic ImagingOpticsRadiation DetectionBackground ReductionRadiographic ImagingImage Acquisition QualityImage Quality TradeoffImaging ResolutionRadiographic Image QualityReduction RatioReticle Design
With higher NA (≫ 0.33) and increased chief-ray-angles, mask effects will significantly impact the overall scanner performance. We discuss these effects in detail, paying particular attention to the multilayer-absorber interaction, and show that there is a trade-off between image quality and reticle efficiency. We show that these mask effects for high NA can be solved by employing a reduction ratio <4X, and show several options for a high-NA optics. Carefully discussing the feasibility of these options is an important part of defining a high-NA EUV tool.
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