Growth of oxide-mediated ternary silicide controlled by a Si cap layer by rapid thermal annealing

We reported a simple method to grow good-quality CoSi2 film by using Si cap technology and introducing moderate Ni. First, a cobalt layer of ∼15 nm with a Si cap layer with a different thickness deposited onto the Si surface with a thin silicon oxide buffer is applied to investigate the formation of CoSi2 by ex situ rapid thermal annealing. It was found that a 13 nm thick Si cap layer could significantly improve the crystal quality of oxide-mediated CoSi2 film. Setting the Si cap thickness at 13 nm, we revealed that introduction of Ni can further improve the crystal quality of the silicide film in comparison to the pure Co silicide, and a ratio of Ni to Co at round 1:8 causes the lowest sheet resistance, ∼5 Ω/sq.