Laser-Assisted Counter-Facing Plasma Focus Device as a Light Source for EUV Lithography

A pair of plasma focus devices was operated with a counter-facing configuration. The focus electrode consisted of six cathodes and a center anode, drove a multichannel discharge. The $2 \times 6$ multichannel discharges were triggered by a YAG laser, which also supplied lithium plasma as the radiation source. A high energy density lithium plasma was formed in the center of focus electrodes, which emitted radiation in an extreme ultraviolet region through the Lyman- $\alpha $ (2p-1s) transition of hydrogenlike lithium ions for pulse duration of more than microsecond. A proof of principle experiment and the latest advances toward realization of a high-average power system are shown.