Extending KrF lithography beyond 80nm with the TWINSCAN XT:1000H 0.93NA scanner

KrF lithography is nowadays widely used for volume production spanning many device layers ranging from front-end 90nm to mid- & back-end layers in 45nm and 32nm ITRS imaging nodes. In this paper we discuss the addition of the new high-NA XT:1000H TWINSCAN(TM)scanning exposure tool to the KrF portfolio. We discuss advances in the system design and elaborate on its imaging and overlay performance. It is shown that stable tool performance supports 80nm resolution volume manufacturing. Extendibility with polarization towards sub-80nm is also addressed.