Nikon EUVL development progress summary

Extreme Ultra Violet Lithography (EUVL) is considered as the most promising technology below hp45nm node(1)), following ArF immersion lithography. In this paper we would like to present significant progress on the development of EUV exposure tool with recent encouraging data of mirror polishing accuracy and evaluation results of Nikon reticle protection concept. EUV exposure tool consists of major important modules such as EUV light source, projection optics, and so on. As far as EUVL optics development is concerned, through the development of high-NA small-field EUV exposure system (HiNA)(2),3)), our mirror polishing and metrology technologies of aspheric mirror surface and multi-layer coating technology have been remarkably improved and enable us to fabricate high-precision aspheric mirrors which meet the specification for EUV pre-production tools called EUV1. In the EUVA (Extreme Ultraviolet Lithography System Development Association) project, we have developed new polishing technologies such as ion-beam figuring and new high-precision interferometers for aspheric surface metrology. Wave front sensor systems have been also developed partly in EUVA project. Installation of a new wave front sensor system which can be used for evaluating the full-field projection optics with EUV light has already been started in New SUBARU synchrotron facility in University of Hyogo. EUV1 tool system design and its detailed design of all modules such as full-field projection optics module, illumination optics module, vacuum body module, vacuum compatible reticle/wafer stage modules, reticle/wafer loader modules have been completed. The results of development and prototyping of major modules such as vacuum stage modules and vacuum body module have been reflected in the actual tool design. Nikon has been also heavily involved in the infrastructure development such as mask handling development. In order to meet industry demands, Nikon has been already getting into EUV1 module fabrication phase. Nikon announces that EUV1 tool is scheduled to be delivered in 1(st) half of 2007.