New neutral cesium evaporation chamber and UHV suitcase

It is well known that the use of Cs+ primary ions results in an important increase of the negative ionization probability during SIMS analyses. Moreover, Cs+ bombardment allows working in the MCsx+ mode, which is a widely used technique to reduce the matrix effect. A major drawback of Cs+ primary ion bombardment is that the Cs+ beam serves both for the incorporation of Cs and for the sputtering of the surface. Therefore, the sputtering yield, and consequently the cesium surface concentration, are constricted by the primary bombardment conditions. To overcome this problem, the Cation Mass Spectrometer (CMS), equipped with an evaporator delivering a collimated and adjustable stream of neutral Cs onto the sample, has been developed at the SAM department. By continuous Cs-0 deposition during the SIMS analysis, optimal Cs surface concentrations, and thus optimal ionization probabilities are obtained.([1]) In order to make the Cs-0 deposition technique available for other analysis instruments, a standalone UHV instrument for Cs evaporation prior to SIMS analyses has been developed. Furthermore, a suitcase for the transfer under UHV conditions of the samples in-between the Cs-0 evaporation chamber and the analysis instruments has been designed, to avoid any contaminations. In this work, we present this new Cs-0 evaporation chamber, as well as our new UHV suitcase in terms of their characteristics and handling. Copyright (C) 2010 John Wiley & Sons, Ltd.