Reduction of the C54-TiSi₂ phase transformation temperature using refractory metal ion implantation

We report that the ion implantation of a small dose of Mo into a silicon substrate before the deposition of a thin film of Ti lowers the temperature required to form the commercially important low resistivity C54-TiSi2 phase by 100-150°C. A lesser improvement is obtained with W implantation. In addition, a sharp reduction in the dependence of C54 formation on the geometrical size of the silicided structure is observed. The enhancement in C54 formation observed with the ion implantation of Mo is not explained by ion mixing of the Ti/Si interface or implant-induced damage. Rather, it is attributed to an enhanced nucleation of C54-TiSi2 out of the precursor high resistance C49-TiSi2 phase.© 1995 American Institute of Physics.