Determination of the mass resolution and the depth resolution of time of flight elastic recoil detection analysis using heavy ion beams

The mass resolution and the depth resolution of the time of flight elastic recoil detection analysis (TOF-ERDA) system for a Si wafer sample have been determined using 20Ne, 40Ar and 136Xe ions as probes. The incident energies were 20.0 MeV for Ne, 41.5 MeV and 22.6 MeV for Ar and 138.1 MeV for Xe, respectively. The mass resolutions of Si were found to be from 1.90 au for 41.5 MeV Ar to 3.32 for 22.6 MeV Ar. Also, the depth resolutions were determined from 1.67x1017 atoms/cm2 for 20.0 MeV Ne to 2.67x1017 atoms/cm2 for 138.1 MeV Xe near to the sample surface. The advantages of each probe ion were compared. A superconductor sample, YBa2Cu3O7-x, was measured using Ar accelerated to 41.5 MeV; Y, Ba, Cu and O were clearly separated. (author)