X-ray laser near 13.5 and 11.3 nm in Xe26+ driven by an intense pump laser interacting with xenon cluster jet as a promising radiation source for nanolithography

Abstract

The model of highly efficient (yield ~0.1–1% of pumping energy) monochromatic radiation sources near λ = 13.5 and 11.3 nm, intended for commercial nanolithography is presented. The sources are based on x-ray lasers on four transitions: 3p53d104l–3p53d104l′ (λ near 13.5 nm) and self photo-pumped 3d 94f (J = 1)–3d 94d (J = 1) (λ ~ 11.3 nm) transition of Ni-like xenon (Xe26+). New inversion mechanisms are discussed. A sufficiently intensive pumping pulse interacting with xenon cluster jet forms plasma. Optimal plasma parameters and quantum yields are predicted for each x-ray laser line. At pump intensities ⩾1018 W cm−2, immediately after the interaction, plasma is formed in the state with dominating Xe26+ ions. This condition is absolutely necessary for the short-lived lasing at 11.3 nm and for the wavelengths of laser transition measurements.