Liquid-target laser-plasma source for X-ray lithography

We describe a compact and practically debris-free laser-plasma x-ray source suitable for proximity lithography. The source is based on a microscopic fluorocarbon continuous liquid jet droplet target, generating high-brightness lambda=1.2-1.7 nm x-ray emission with similar to 5% conversion efficiency. This target type has the advantages of producing only negligible amounts of debris, and being regenerative, thereby allowing high-repetition-rate uninterrupted operation. The source is combined with an Au/SiNx x-ray mask to demonstrate lithography of sub-100 nm structures in SAL-601 chemically enhanced resist