Performance of gas jet type Z-pinch plasma light source for EUV lithography

A new gas jet Z-pinch extreme ultraviolet (EUV) light source having double gas jet electrodes has been developed. It has two nozzles and two diffusers. The EUV emission is collected from the side of Xe pinch plasma, which is generated in a gap between the inner nozzle and corresponding diffuser. A cylindrical shell of He gas curtain produced by the outer nozzle is specially designed for shielding the debris and suppressing the inner gas expansion. We have estimated EUV energy of 1.22 mJ/sr/pulse for a 2% bandwidth at 13.5 nm in the presence of the gas curtain. The estimated diameter and length of EUV source in FWHM are 0.07 mm and 0.34 mm, respectively, whereas the same in FW 1/e2 are 0.15 mm and 1.2 mm, respectively.