Stagnation layer development from two colliding Sn plasmas for an efficient EUV source

Abstract

The collision of two laser-produced plasmas (LPP), individually generated from the opposing faces of a tin wedge, was studied experimentally and through the HEIGHTS computer simulation package to explore onset and development of the stagnation layer and extreme ultraviolet (EUV) photoemission. The colliding Sn plasma offers promise for a powerful source of 13.5 nm light, the industry-identified wavelength being targeted for commercial EUV lithography light sources. A second laser pulse could efficiently couple with the material accumulated along the collision midplane to produce EUV with high power. Imaging of the LPP configuration is accomplished using an ICCD camera while electron temperature and density of the stagnation layer were determined using spectroscopic methods—both were verified using HEIGHTS which was also used to show the potential of an EUV source with 700 W power at the intermediate focus for efficient high-volume manufacturing.