Thermal stability of NiSi controlled by post silicidation metal doping method

Silicidation process and effects of various kinds of additive metals for the improvement of thermal stability of Ni silicide were examined carefully for the 45 nm node. In order to obtain heat resistant NiSi, introduction of various metal layers introduced to top or bottom (interface of Ni/Si) of Ni on Si were investigated. However, we couldn't have any improvement in the thermal stability by any additive metals introduced. Base on that result, we proposed "post silicidation metal doping" (PSMD) method. As the result of the comprehensive experiments for 7 kinds of the additive metal, it was suggested that the combination of preformed NiSi and Pt or Hf addition is the solution to improve the NiSi thermal stability