Recent advancements in 193 nm step and scan lithography.

Abstract

With the introduction of full field step&scan systems, 193nm technology development is currently being accelerated and resists are used closer to their final area of application, i.e. under realistic conditions of lens aberrations, stray-light and wafer coverage. In this paper, the lithographic performance of advanced 193nm resist materials has been evaluated on a full field step&scan system. Single layer and hi-layer resist processes are compared in terms of performance and complexity. Very similar lithographic performance is observed for both the single layer and the bi-layer approaches at 130nm. Optimization of illumination conditions (NA, sigma) is investigated as a way to enlarge processing windows and to reduce iso-dense bias. The application of a PSM illustrates the extendibility of 193nm lithography for the 100nm technology node. In general, significant progress in resist performance has been made but further improvements are needed before 193nm resists will reach the maturity level of today's state-of-the-art 248nm resists.