Liquid-jet target laser-plasma sources for EUV and X-ray lithography

We describe a new high-brightness laser-plasma source for X-rays and extreme ultraviolet (EUV) radiation. By utilizing a liquid target the harmful emission of debris is significantly reduced or completely eliminated. The spectrum can be spectrally tailored by choosing a suitable liquid. We also show the possibilities to extend the debris-free source to liquid solutions of solids and to liquefied gases. This results in new emission wavelengths and offers the possibility to increase conversion efficiency. We believe that this new source is a suitable choice for EUV lithography as well as for proximity X-ray lithography.