Abstract
Formation of TiSi 2 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-TiSi 2 by about 100°C. A ternary (Ti, Mo) Si 2 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-TiSi 2 . 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 BF 2 + or As + + 20 keV, 1 × 10 15 /cm 2 N 2 + implanted samples, a continuous C54-TiSi 2 layer was found to form in all samples annealed at 650-950°C. The presence of nitrogen atoms in TiSi 2 is thought to lower the silicide/silicon interface energy and/or the silicide surface energy to maintain the integrity of the C54-TiSi 2 layer at high temperatures.