Abstract.
Since 2002, we have been developing a -Sn-laser plasma produced (LPP) extreme-ultraviolet (EUV) light source, the most promising solution as the 13.5-nm high-power () light source for high-volume manufacturing (HVM) EUV lithography. Because of its high efficiency, power scalability, and spatial freedom around plasma, we believe that the -Sn-LPP scheme is the most feasible candidate as the light source for EUVL. By now, our group has proposed several unique original technologies, such as laser-driven Sn plasma generation, double-laser pulse shooting for higher Sn ionization rate and higher CE, Sn debris mitigation with a magnetic field, and a hybrid laser system that is a combination of a short-pulse oscillator and commercial cw- amplifiers. The theoretical and experimental data have clearly demonstrated the advantage of combining a laser beam at a wavelength of the laser system with Sn plasma to achieve high CE from driver laser pulse energy to EUV in-band energy. We have the engineering data from our test tools, which include 20-W average clean power, , and 7 h of operating time; the maximum of 3.8% CE with a 20-μm droplet, 93% Sn ionization rate, and 98% Sn debris mitigation by a magnetic field. Based on these data, we are developing our first light source for HVM: “GL200E.” The latest data and the overview of EUV light source for the HVM EUVL are reviewed in this paper.
