Antimony dopant redistribution during copper silicide formation

In the present work, copper silicide formation and the redistribution of implanted Sb+ ions were studied by means of Rutherford backscattering spectrometry (RBS) and X-ray diffraction (XRD). Copper thin films, of 500 Å thickness, were evaporated, at room temperature, onto Sb implanted Si(111) wafers. Two doses, 5×1014 and 5×1015 Sb+ cm−2, were used at 130 keV. The samples were heat treated in vacuum by conventional thermal annealing in the temperatures range 500–700°C for various times. It was observed that, independent of Sb implant dose, two silicides (Cu3Si and Cu4Si) were formed in the considered temperature range. Antimony ions implanted initially in the Si substrates were found to redistribute towards the sample free surface.