Formation of C54–TiSi2 in titanium on nitrogen-ion-implanted (001)Si with a thin interposing Mo layer

Formation of TiSi2 in titanium on nitrogen-implanted (001)Si with a thin interposing Mo layer has been investigated. The presence of a Mo thin interposing layer was found to decrease the formation temperature of C54–TiSi2 by about 100 °C. A ternary (Ti, Mo)Si2 phase was found to distribute in the silicide layer. The ternary compound is conjectured to provide more heterogeneous nucleation sites to enhance the formation of C54–TiSi2. On the other hand, the effect of grain boundary for decreasing transformation temperature was found to be less crucial. For Ti/Mo bilayer on 30 keV BF2+ or As+ + 20 keV, 1 × 1015/cm2 N2+ implanted samples, a continuous C54–TiSi2 layer was found to form in all samples annealed at 650–950 °C. The presence of nitrogen atoms in TiSi2 is thought to lower the silicide/silicon interface energy and/or the silicide surface energy to maintain the integrity of the C54–TiSi2 layer at high temperatures.