Emission Stability of Au–Si–Be LM Ion Source in Various Gas Environments

Abstract

Emission stability of a Au–Si–Be liquid metal (LM) ion source under various gas environments has been investigated. It was found that the ion emission stability was influenced by oxygen or water vapor which seemed to result in oxidation of the alloy surface. Water vapor is particularly active with Be atoms in the alloy. We have confirmed that stationary, stable ion beams (Si, Be) with a constant ion current and a beam diameter can be obtained by operating the ion source under a high vacuum enclosure of 2×10-7 Torr in a 100 kV focused ion beam implanter (FIBI).