NEW CHARACTERIZATION METHOD OF ION CURRENT-DENSITY PROFILE BASED ON DAMAGE DISTRIBUTION OF GA-ION BEAM IMPLANTATION IN GAAS( FOCUSED)

A new method is reported for characterizing focused ion probe current distributions based on the comparison between damage simulations and t ransmission electron microscopy observations. Several focused-ion beam operation conditions were modeled, such as low-to-high source emissio n currents and variable beam acceptances. At low current and small acc eptance, the ion spot exhibits a nearly Gaussian profile, otherwise la rger tails are evidenced which can be modeled either by Pearson or ''b i-Gaussian'' distributions. The sensitivity of the procedure to the ta il extension is highlighted.