Mixing in Au/Ge system induced by Ar+ ion irradiation

Rutherford Backscattering Spectrometry (RBS) and Electrical Resistivity Measurements (ERM) were used to investigate the mixing of Au/Ge bilayer deposited onto glass substrate induced by Ar ions. Mixing was initiated by bombarding the sample with 400 keV 40Ar+ beam with a fluence up to 1.2 · 1017 ions/cm2 at a constant flux of 0.25 lA/cm2. To assist the evaluation of the experimental results, all spectra were simulated using ‘‘RUMP’’ computer code. RBS results indicated that ion beam mixing led to a formation of AuGe2 compound. The mixed region was noticed to increase with the gradual increase of Ar+ fluence. Results were also compared with current theoretical models used to describe the mixing process. The B/rgesen thermal spike model was found to accurately predict the diffusion in Au/Ge interface. An increase in the electrical resistivity of the film was detected during Ar+ irradiation.