Spectroscopic investigations of YAG-laser-driven microdroplet-tin plasma sources of extreme ultraviolet radiation for nanolithography

Abstract

Synopsis Highly charged tin ions are the sources of extreme ultraviolet (EUV) light at 13.5-nm wavelength in laser-produced transient plasmas for next-generation nanolithography. Generating this EUV light at the required power, reliability, and stability however presents a formidable task that combines industrial innovations with challenging scientific questions. We will present work on the spectroscopy of tin ions in and out of YAG-laserdriven plasma and present a surprising answer to the key question: what makes that light?