Barrier layer formation on CoSi2surface by NH3plasma treatment

Al-CoSi 2 reaction at 430 °C is suppressed by NH 3 plasma exposure to the CoSi 2 surface before Al deposition. An amorphous 5nm-thick Co-Si-N-O layer formed with the plasma treatment prevents Co 2 Al 9 or Co 4 Al 13 formation during annealing. N is combined with Si at the surface, but presumably with Co inside of the Co-Si-N-O layer. This technology is useful to form barrier layers on the silicide layer at low temperatures.