Refractory metal silcides are under intensive investigation to be used as contact and interconnect materials in VLSI circuits. Ion beam mixing has been proposed as a technique for simultaneous doping and metal silicide formution. This work presents a theoretical model for calculating the different parameters required for ion beam mixing through ion implantation. The minimum ion beam energy and dose for complete mixing is calculated. A plot of the obtained energy-dose relation shows that the dose increases linearly with energy. The dose-silicide thickness relation is also plotted. It is found that the thickness of the formed metal silicide increases linearly with the square root of the applied dose. A good agreement is found between the values and relations of the proposed model and experimental results.