RUTHERFORD BACKSCATTERING SPECTROSCOPY OF INSULATING MATERIALS

A method of analysing RBS spectra that show the effects of surface charging, and a software package (called BAS) incorporating the method are described. The experimental procedure for successful analysis of insulating materials is also explained. BAS is used to analyse three ion implants of copper, silver and gallium into soda-lime glass, silica and YAG, respectively. The results of the analyses compare favourably to simulations using RUMP and TRIM, with the advantage that the BAS calculations are performed more quickly and require less prior knowledge of the material being analysed. The copper implant has a dose retention of 98% and the profile is only a little lower and broader than predicted by TRIM. The silver implant has a low retention of 42% and accordingly the depth profile is very different from the TRIM prediction. The gallium implant has a dose retention of 99%. The depth profile is narrower than the TRIM prediction, indicating that the gallium is restricted in movement by the chemically similar aluminium in the YAG.