Device shrink is the key drive of the semiconductor industry for decades to enable cheaper and faster electronic devices with more functionality and lower energy consumption. In this paper we report on the performance enhancements on the
NXT immersion scanner platform to support this device shrink roadmap using our immersion lithography systems. We particularly discuss and share data on the overlay and focus performance improvements in our latest NXT immersion
system. Related to overlay we describe the improvements in grid calibrations and grid matching; thermal control of reticle and wafer; aberration tuning and FlexWave-lens heating control as well as aberration- and overlay-metrology on
wafer-2-wafer timescales. Finally, with respect to focus performance, we will address reduction of leveling process dependencies, stage servo dynamics and wafer table flatness to enhance on-product focus and leveling performance.
Keywords: Immersion lithography, exposure systems, ArF, overlay, imaging, focus.