Enhancement of extreme ultraviolet emission from a CO2 laser-produced Sn plasma using a cavity target

We demonstrated enhancement of in-band conversion efficiency (CE) at 13.5 nm of the extreme ultraviolet (EUV) emission from a tin (Sn) cavity target irradiated by a CO(2) laser pulse. Whereas a planar Sn target produced an in-band CE of around 2%, the use of cavity targets significantly enhanced the EUV emission energy and the EUV CE. An EUV CE of 4% was observed for a Sn cavity target with a depth of 200 mu m which is one of the highest values ever reported.