The Repeller Field debris mitigation approach for EUV sources

We describe studies of the debris produced from a high–repetition-rate laser plasma EUVL source based on the mass-limited target concept. In particular, we are developing mass-limited target designs based on complex targets containing tin. Comprehensive analysis of witness-plate detection techniques can reveal many interesting details of the interaction regime, and the impact of the debris. These techniques include Optical Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy, X-ray Photoelectron Spectroscopy, Auger Electron Spectroscopy, and Auger Electron Microscopy. We also describe developments of the repeller field concept of debris inhibition. This technique uses electrostatic fields to reduce the flux of plasma ions impinging on the EUV collimating optics. Here, the first measurements of debris mitigation of a tin-doped target are described, and comparisons with earlier measurements of the impact of repeller fields on ion emission from a mass-limited water-droplet target are made.