Abstract
Backscattering spectrometry and X-ray diffraction were used to investigate the mixing in Si/Co and Co/Si bilayers, deposited onto SiO
2 substrates, induced by irradiation with 300 keV Xe
+ ions. The ion range was near the CoSi interface in each case. The irradiation was performed at temperatures and doses ranging from -194 to +245 °C and from 2 × 10
15 to 5 × 10
16 Xe
+ ions cm
-2 respectively. The irradiation produces intermixing at all temperatures. The X-ray results show that at room temperature Co
2Si is formed, while above room temperature both Co
2Si and CoSi are formed simultaneously. At room temperature, 100 and 200 °C the total amount of silicide formed increases with the square root of the xenon dose. The temperature dependence of mixing (“
Q curve”) at the doses of 10
16 and 5 × 10
16 Xe ions cm
-2 for both bilayer types rises rapidly above 24 °C and changes little below that temperature. The apparent activation energy extracted from the high temperature part of the
Q curve is 0.33 ± 0.05 eV. These results confirm that in the temperature-activated regime, the phases observed after ion mixing are the same as those found on thermally annealing the sample.