Development of the next-generation ArF excimer laser with ultra-narrow stable spectral bandwidth for multiple patterning immersion lithography

The multiple patterning ArF immersion lithography has been expected as the promising technology to satisfy leading edge device requirements. Gigaphoton carries out developments to improve device yields and to reduce costs of operation in exposure. One of them is ultra-narrowing spectral bandwidth of light source without Helium gas usage. The ingenious configuration of Line Narrowing Module (LNM) allows E95 bandwidth to reach 200 fm from 300 fm in Helium free operation. Narrower bandwidth will improve exposure latitude. Helium free operation will reduce operational costs and will be independent of Helium gas shortage. Second is improving stability of bandwidth. 5 fm E95 bandwidth shot average can be realized by adopting a new fast actuator and a new control method. Stable bandwidth will improve CD uniformity. They are also able to broaden a bandwidth tuning range and to make a bandwidth tuning speed faster. New type LNM and new bandwidth control that Gigaphoton has developed realize ultra-narrow bandwidth, Helium free operation, stable bandwidth, broad bandwidth tuning range and fast bandwidth tuning speed. They will contribute to the improvement of device yield in cutting edge exposure condition and the reduction of operational costs. These functions can be upgradable for our ArF excimer laser.