Abstract: A new technology for the fabrication of self-aligned silicided MOS transistors was investigated. Self-aligned highly conductive CoSi₂ films were formed on the areas of the source/drain and gate electrode by solid state reaction of Co/Si.Dopants were implanted through CoSi₂/Si. The dopant and damage depth profiles were calculated by the eomputer program TRIM. The ion energy was properly selected to make the peak of dopant concentration locate at the interface of CoSi₂/Si. By a rapid thermal annealing after implantation, high-performance enhanced and depletion MOS transistors were fabricated with high carrier concentrations at the interface of CoSi₂/Si. The redistribution of the implanted dopants in the structure of CoSi₂/Si during different thermal processes was also studied. The results show that phosphorous has the tendency of diffusing into Si substrate, but boron prefers to stay in CoSi₂.

Key words: interface, rapid thermalannealing, MOS transistor, ion implantation