Optimization and stabilization of a compact laser-plasma EUV source based on pulsed Xe/He double-stream gas jets

We present our progress of a compact laser-plasma extreme ultraviolet (EUV) source based on Xe/He double-stream gas jets irradiated by a 700-mJ Nd:YAG laser. The source was characterized using a flat-field spectrometer, an absolutely calibrated EUV energy meter, and a pinhole camera imaging system. A Maximum single-pulse EUV intensity of 2.36 mJ was achieved at 13.5 nm (2% bandwidth, 2π sr), corresponding to a conversion efficiency of 0.34%. Meanwhile, the plasma size was reduced to a length of 560 μm and a diameter of 160 μm when observed at a 90° angle relative to the laser. An intensity stability of 0.52% (1σ, 100-pulse window) was achieved over 3000 pulses when stabilizing the back pressure of the Xe gas with a pressure controller. This EUV source is applicable to various EUV metrology applications.