Growth of titanium silicide on ion-implanted silicon

• Published in: Journal of applied physics 1983-01, Vol.54 (4), p.1860-1864
• Main Authors: Révész, P., Gyimesi, J., Zsoldos, É.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.332237

Silicon samples implanted with high doses of 121Sb, 75As, 31P, 16O, and 40Ar prior to Ti evaporation were studied to measure the growth of Ti-silicide layers. The annealing behavior of these samples was investigated by four-point probe measurement, Rutherford backscattering, and by x-ray diffraction. The samples implanted with Sb, As, and P atoms enabled the growth of TiSi2 to be observed, though its final thickness was less than half when compared to that of the nonimplanted samples. Simultaneously with the diffusing-out atoms of Sb, during annealing, segregation of Sb atoms takes place at the TiSi2/Ti interface and at the Ti surface. Using a simple model for the out-diffusion of Sb atoms, the activation energy of the diffusion coefficient of Sb in the Ti silicide was determined, giving a value of Ea=1.9 eV. During out-diffusion, As atoms tend to be distributed homogeneously in the silicide layer. With Ar- and O-implanted samples, precipitation of Ti atoms can be observed at the implantation depth, and at higher annealing temperatures, the metal layer flakes off the sample. A simple model is given to explain this behavior. X-ray diffraction measurements of these samples showed the presence of the unstable TiSi phase, but no trace of the TiSi2 phase was found after annealing at 700 °C.