6.7-nm Emission from Gd and Tb Plasmas over a Broad Range of Irradiation Parameters Using a Single Laser

As we follow Moore's Law and pack more and more components onto each computer chip, we must extend the limits of manufacturing. Looking ahead, efficient sources of light at a wavelength around 6.7 nm are needed for beyond-extreme-ultraviolet (BEUV) lithography, to create integrated circuits beyond the 7-nm logic node. This study measures and models plasmas of Gd and Tb, prepared using a single laser tuned over a broad range of parameters. These plasmas do emit at the desired wavelength, and calculations indicate that a conversion efficiency of 6% could ultimately be realized.