Liquid metal ion source working with an Er70Fe22Cr5Ni3 alloy

A liquid metal ion source operating with an Er-stainless steel alloy was de veloped and investigated for focused ion beam applications of erbium as wel l as of several metal ions which are of interest for optical and semiconduc tor investigations. This alloy consists of a mixture of Er70Fe22Cr5Ni3 and has a melting point of about 860 degrees C. The wetted-needle-type tungsten emitter showed a stable emission behaviour down to 1 mu A emission current . The I-V characteristics, the temperature dependence of the extraction vol tage, the mass spectrum and the energy spread of the main beam components d epending on the emission current were investigated. While in the case of si ngly charged metal ions the beam is not defined due to isotope interference , in the case of doubly charged ions the species that are well separated fo r focused ion beam applications are available.