Modeling of EUV emission and conversion efficiency from laser-produced tin plasmas for nanolithography

Extreme ultraviolet lithography (EUVL) is a leading candidate for use in next-generation high volume manufacturing of semiconductor chips that require feature sizes less than 32 nm. The essential requirement for enabling this technology is to have a reliable, clean and powerful EUV source which efficiently emits light at a wavelength of 13.5 nm. Laser-produced plasma EUV sources are strong candidates for use in EUVL light source systems. The development and optimization of high-efficiency EUV sources requires not only well-diagnosed experiments, but also a good understanding of the physical processes affecting the emitting plasma, which can be achieved with the help of accurate numerical simulation tools. Here, we investigate the radiative properties of tin and tin-doped foam plasmas heated by 1.06 μm laser beams with 10 ns pulse widths. Results from simulations are compared with experimental conversion efficiencies and emission spectra.