Abstract

Contamination of critical components within expensive high-vacuum process technologies poses a serious obstacle to their implementation. Of particular interest in this talk is the Next-Generation semiconductor fabrication technique of Extreme Ultra-Violet Lithography (EUVL). Highly expensive multilayer mirrors, used to reflect radiation, are critically damaged by extremely low partial pressures of certain hydrocarbons and therefore there is an urgent need for selective, sensitive, robust, high-vacuum compatible sensors to be placed at key locations. We have taken two different approaches to develop hydrocarbon sensors, based on the solid state electrolyte YSZ . I will introduce each design and demonstrate operation under real working conditions. (Amy Stevens)

Low Energy Electron Diffraction (LEED) is one of the principal experimental techniques for the accurate determination of structure of periodically ordered surfaces. However, conventional LEED optics operate with a beam current in the order of µAmps and this can result in electron beam damage to the surface . Consequently, it has not hithero been possible to make a structural determination by LEED of molecular adsorbate surface systems. Our Fibre Optic LEED instrument has been designed to operate at nAmp beam currents, allowing us to push the boundaries of which adsorbate-surface systems we can investigate. I will present a study of water on Cu{110}, a system for which there is a lack of experimental work due to its sensitivity to electron beam damage. This study not only demonstrates the Fibre Optic LEED ’s ability to examine an electron beam sensitive system but also seeks to address a key question: does the water bilayer exist as intact or partially dissociated on copper surfaces? (Chloe Stockford)