Lithography Process Transfer from ArF to High-NA KrF Tool

Abstract

In this paper, we present the capabilities of lithographic process transfer by use of high NA KrF tool (TWINSCAN XT:1000H, Maximal NA 0.93). The Metal 1 (100 nm half-pitch)and Via (110 nm half-pitch) layers of 65 nm technology have been chosen for this research. The layers belong to customer product that is currently manufactured on ArF tool (TWINSCAN XT:1400). By optimizing illumination setting and applying advanced OPC solution, we have obtained the overlapping process window of critical features for the KrF process that is comparable with parameters of the initial ArF process. A good performance of Metal layer with respect to MEEF (Mask Error Enhancement Factor) also allows for stable process characteristics within wide line through pitch range. However, to ensure CD uniformity for Via layer an aggressive illumination solution such as soft-QUASAR or customized illumination may be required.