Understanding EUV-induced plasma and application to particle contamination control in EUV scanners

Abstract

With the introduction of the NXE:3400B scanner, ASML has brought EUV to High-Volume Manufacturing (HVM). In this context, ASML is pursuing a dual-path approach towards zero reticle defectivity: EUVcompatible pellicle or zero particles towards reticle by advanced particle contamination control. This paper will focus primarily on the approach of advanced particle contamination control and on the understanding of EUV-induced plasma to control both release and transport of particles within the scanner. This paper will present our advancements in understanding and control of particle forces related to the EUV-induced plasma, for EUV sources up to 250W and beyond. This will combine models and simulations with off-line experiments as well as in-situ scanner tests. It will be shown that our understanding of the underlying mechanisms of plasma-induced release and transport of <1um particles enables us to manage defectivity levels down to be compatible with HVM requirements for sub-10nm node lithography.