Improvement of Ni Silicide Thermal Stability By Using Vanadium Elements

Ni silicide thermal stability is improved by the use of a Ni-V (nickel vanadium) alloy target. The relationship between the formation temperature and the thermal stability of Ni silicide is investigated. The sheet resistance after the formation of Ni silicide with the Ni-V shows stable characteristics up to a rapid-thermal-process temperature of 700°C, while degradation of sheet resistance starts at that temperature in the case of pure-Ni. Moreover, the thermal stability improvement is demonstrated by the post-silicidation annealing. It is considered that the thermal robustness of Ni-V silicide is highly dependent on the formation temperature. With the increasing silicidation temperature (around 700°C), more thermally stable Ni silicide is formed in comparison to the low-temperature case using the Ni-V. A Ni-V alloy target is utilized to form Ni silicide. The V and the V-trap complexes are explained to block the transformation from NiSi to NiSi₂ so as to improve the Ni silicide thermal stability.