High-Power EUV Source for Lithography Using Tin Target

Xenon capillary discharge sources are being developed for extreme ultraviolet (EUV) light for next generation lithography. However, the current sources generate in-band (2%), 2pi EUV emission with conversion efficiency (CE) of <1%. Here we report progress in the development of a Z-pinch EUV source using a tin target, which was found to have significant potential for high conversion efficiency with wavelength of 13.5 nm. Xenon was used as the background gas, the experiments shew that the magnitude of the EUV emission depended on not only the distance between the plasma and the rod surface, but also the pulse repetition rate of the discharge. Pinhole imaging, an EUV spectrograph and an in-band EUV energy monitor were used to characterize the EUV emission from the Z-pinch discharge.