Liquid-tin-jet laser-plasma extreme ultraviolet generation

Abstract

We demonstrate the applicability of liquid-metal jets in vacuum as regenerative targets for laser-plasma generation of extreme ultraviolet (EUV) and soft x-ray radiation. This extends the operation of liquid-jet laser-plasma sources to high-temperature, high-Z, high-density, low-vapor-pressure materials with new spectral signatures. The system is demonstrated using tin (Sn) as the target due to its strong emission around λ≈13 nm, which makes the material suitable for EUV lithography. We show a conversion efficiency of 2.5% into (2%BW×2π×sr) and report quantitative measurements of the ionic/atomic as well as particulate debris emission.