Parametric study of extreme ultraviolet light source from 1- <i>μ</i> m-wavelength lasers via a simulation approach

Abstract

Extreme ultraviolet (EUV) lithography, the patterning of fine semiconductor features with EUV light, is based on efficiently generating radiation within a narrow bandwidth around 13.5 nm by laser-produced plasma. In this work, we conducted a comprehensive computational study, following validation of our simulations with benchmark experiments, to assess how different parameters of a 1-μm-wavelength laser impact plasma dynamics and radiation emissions, including spectra, anisotropy, and evaluation of conversion efficiency. The results indicate that while total EUV power increases with both laser intensity and pulse duration, a distinct threshold exists beyond which the conversion efficiency of in-band EUV begins to diminish: The optimal laser intensity for conversion efficiency and isotropy of EUV emission in both spherical and disk targets lies around 1011W/cm2. Furthermore, the 1-μm-wavelength lasers exhibit a lesser dependence of EUV yield upon the interaction area and pulse duration of laser, compared to the 10 μm wavelength case.