Novel NiSi technology utilizing Ti/Ni/TiN structure and fluorine implantation for thermal stability improvement by suppression of abnormal oxidation

A novel NiSi technology is proposed to improve the thermal stability and to suppress the abnormal oxidation of NiSi, which occurs especially on the As-doped substrate. The dependence of Nickel-Silicide property on the source/drain dopants has also been characterized. Although there is minimal dependence of NiSi on the dopants right after the silicide formation, NiSi is strongly dependent on the source/drain dopants when high temperature post silicidation furnace annealing is applied. BF₂-doped source/drain shows much superior thermally robust characteristics than As-doped source/drain mainly due to the abnormal oxidation of As-doped substrate after the furnace annealing. A novel Ti/Ni/TiN structure with fluorine ion implantation (F I/I in short) showed the great improvement of the thermal stability as well as the suppression of the abnormal oxidation especially on the As-doped source/drain.