Liquid-target laser-plasma sources for EUV and x-ray lithography

We review the development of compact laser-plasma soft x-ray sources based on microscopic liquid drops or liquid jets as target. It is shown that such sources provide practically debris-free, high-flux operation at wavelengths suitable for EUV and x-ray lithography. This regenerative and liquid- density target system holds promise for high-average power x- ray and EUV generation using high-repetition-rate lasers. Application of the method to compact x-ray microscopy is also briefly discussed.