Property of cobalt nickel silicide by thermal annealing of Co/Ni bilayer on a silicon substrate

15 nm-Co/15 nm-Ni/p-Si (100) was thermally annealed using rapid thermal annealing for 40 s at 700-1100°C. The annealed bilayer structure developed into the composite CoNiSi_x and the resulting changes in sheet resistance, microstructure, and composition were investigated using a four-point probe, transmission electron microscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. The final thickness of the composite CoNiSi _x was approximately 100 run and it maintained its sheet resistance below 5 Ω/sq after silicidation annealing at 1100°C. The proposed CoNiSi_x suicides may be superior to conventional single phased suicides due to their improved thermal stability and thickness adjustment.