Applications of accelerator mass spectrometry to electronic materials

Applications of accelerator mass spectrometry (AMS) to stable-element detection in electronic materials are being explored. Conventional AMS hardware at the University of Arizona has been used to profile shallow semiconductor structures (ion-implanted samples) and to establish minimum values of system efficiency for several ions in Si and/or GaAs. A custom instrument under development at the University of North Texas has been used to generate molecule free mass spectra which can be directly compared with secondary-ion mass spectrometry (SIMS) data. Elemental fragments associated with molecular dissociation after passage through the accelerator are shown to constitute a source of system “background” which can be removed through clever selection of charge states.