An X-ray exposure system for 100-nm-order SR lithography

An x-ray exposure system for 100-nm-order synchrotron radiation lithography is now being developed. We focused on improving the resolution, alignment accuracy, and beam-intensity uniformity. The key technologies are a flat wafer chuck to enable the use of narrower gaps, high repeatability in positioning and alignment, and the use of vignetting plates to obtain a uniform intensity. Currently, the resolution is less than 120 nm, the alignment repeatability is less than 14 nm, the positioning repeatability is less then 7 nm, and the intensity variation is less than ±6%. This system has been installed in the SR facility at the NTT Atsugi Research Center and is being used to conduct feasibility testing.