Low density targets for laser-produced-plasma (LPP) extreme ultraviolet light source with high-CE and toward high-repletion supply

Abstract

In the present paper, we overview fabrication methods to produce density-controlled tin and xenon targets for generating extreme ultraviolet (EUV) light. The target can be classified as a mass-limited target. In the case of tin, EUV was relatively monochromatic, and its conversion efficiency was higher than bulk tin. Using the nano-template method, the cellular foam size was controlled by the template size. The density was 0.5 ~1.5 g/cm³. In the case of the 0.5 g/cm³ foam, its morphology was controlled by changing the ethanol content of the precursor tin solution. The morphology difference was useful to control the angular distribution of EUV radiation. SnO₂ nanofiber, which is oriented low-density material, was fabricated continuously using a electrospinning method. The width and the shape of the fiber were controlled by optimizing precursor solution. A transparent film with tin and SnO₂ elliptic spheres were prepared using liquid crystalline cellulose derivative. Low density xenon was prepared from liquid xenon using a swirl atomizer to produce a density of 0.2 g/cm³.