Experimental Results Obtained using Extreme Ultraviolet Laboratory Tool at New SUBARU

We have designed three-aspherical-mirror optics that meets the specifications for 0.1 µm generation lithography, and are developing an extreme ultraviolet lithography (EUVL) laboratory tool suitable for device fabrication experiments. It operates at a wavelength of 13.5 nm and employs a three-mirror imaging system with a numerical aperture of 0.1. It is capable of replicating 65 nm patterns in an exposure field of 30 mm×1 mm size. First, single-layer chemically amplified resists are investigated using the synchrotron radiation (SR) source of New SUBARU. From the sensitivity curve, it was found that the positive-tone resist DP603 and the negative-tone resist SAL601 have high gamma values and high sensitivities to the extreme ultraviolet exposure wavelength. Furthermore, exposure experiments using the three-aspherical mirror imaging system were performed. A minimum line width of 56 nm was demonstrated in an exposure area of 10 mm×1 mm. We confirmed that the three-aspherical mirror imaging system is useful for developing EUVL technology.