High-power gas-discharge EUV source

Abstract

The results from studies aimed at creating a high-power high-repetition-rate gas-discharge EUV source based on xenon Z-pinch are presented. In a liquid-cooled EUV source prototype, an average output power of 10 W for the burst mode (∼1 s) and 5 W for continuous operation, emitted into a solid angle of 0.25 sr and 2% bandwidth around 13.5 nm is attained at a repetition rate of ∼1 kHz. Operating wavelength of the source corresponds to XeXI 13.5-nm ion emission band. It is experimentally shown that the size of the emitting hot plasma can be decreased to ∼2 mm without loss in the average output power. The radiation characteristics were determined by using standard techniques and calibrated metrology tools, which allowed a comparison of the absolute values of the measured parameters with the available data on other EUV sources developed for the next-generation lithography with a resolution of ∼50 nm. The attained level of an average EUV power of 10 W at λ=13.5 nm into the 0.25-sr solid angle and 2% bandwidth is one of the highest at the moment.