Characterization of various Sn targets with respect to debris and fast ion generation

Abstract

We evaluated Sn debris generated from a CO₂ laser (10.um) and a Nd:YAG laser (1064nm) plasma. Experiments were performed with bulk Sn-plates (t=1mm) and freestanding Sn-foils (t=15um). Quartz Crystal Microbalances (QCM) were used for debris analysis. We observed a drastically lower deposition for the CO₂ laser driven plasma compared with the Nd:YAG laser plasma. In addition, several Sn coated targets with different Sn thickness were investigated for the CO₂ drive laser with respect to the generated plasma debris. In general, a 100nm Sn coated glass target generated more debris than the solid Sn target. Especially, we observed for the Sn-plate target that the deposition rate is smaller than the erosion (sputter) rate caused by the plasma ions.