Ring-field extreme ultraviolet exposure system using aspherical mirrors

We have designed and started the fabrication of 3-mirror ring-field project ion optics for extreme ultraviolet lithography (EUVL) and an experimental e xposure system using the projection optics, which enable a large-field (30 mm x 20 mm), high-resolution (<100 nm) exposure. EUV exposure experiments w ill be performed using the EUVL beam line to be constructed at the new sync hrotron ring called New Subaru, which is now under construction in Hyogo Pr efecture. In this paper the details of the EUV exposure system will be desc ribed.