CO2 laser-produced Sn-plasma source for high-volume manufacturing EUV lithography

We are developing a laser produced plasma light source for high volume manufacturing (HVM) EUV lithography. The light source is based on a high power, high repetition rate CO 2 laser system, a tin target and a magnetic ion guiding for tin treatment. The laser system is a master oscillator power amplifier (MOPA) configuration. We have achieved an average laser output power of 10 kW at 100 kHz by a single laser beam with good beam quality. EUV in-band power equivalent to 60 W at intermediate focus was produced by irradiating a tin rotating plate with 6 kW laser power. This light source is scalable to more than 200 W EUV in-band power based on a 20-kW CO 2 laser. Collector mirror life can be extended by using droplet target and magnetic ion guiding. Effectiveness of the magnetic ion guiding is examined by monitoring the motion of fast Sn ion in a large vacuum chamber with a maximum magnetic flux density of 2 T.