FAST ATOM BEAM BOMBARDMENT SECONDARY-ION MASS-SPECTROMETRY - FAB-SIMS

FAB-SIMS is a surface analysis method that uses bombardment by a fast atom beam as the probe instead of a conventional ion beam. Because FAB carries no electric charge, this method is particularly effective for insulator analysis. An apparatus for FAB-SIMS consists of a FAB source, a secondary ion detector with an energy filter, and a quadrupole mass filter. The FAB source is operated under a DC diode discharge. This source has useful characteristics for controlling the energy and density of the FAB. The ion energy filter is composed of four wire electrodes and has been investigated through experiments and numerical simulations. Because the filter can separate positive and negative ions, attaching the filter on the stage next to the quadrupole mass filter enables simultaneous detection of positive and negative secondary ions in the FAB-SIMS apparatus.