Formation of iridium silicide layer by high dose iridium ion implantation into silicon

We have investigated the formation of IrSi₃ layers buried in (111) silicon. The layers are formed by iridium ion implantation at room temperature using a metal vapor vacuum arc (MEVVA) high current metal ion source with an average beam energy ≈ 130 keV. Doses of the Ir ions ranging from 2 × 10¹⁶ to 1.5×10¹⁷/cm² Were implanted into (111) Si. We have successfully formed a buried silicide layer in silicon by room temperature implantation and annealing. The formation of IrSi₃ phase is realized after annealing at temperatures as low as 500°C. A continuous IrSi₃ layer of ≈ 200 Å thick buried under ≈ 400 Å of Si was achieved with samples implanted with doses not less than 3.5 × 10¹⁶/cm². Implanted doses above 8 × 10¹⁶cm² resulted in the formation of an IrSi₃ layer on the surface due to excessive sputtering of Si by the Ir ions. The effects of implant dose on the phase formation mechanism, the interface morphology and the implanted atom redistribution are discussed. Radiation damage and regrowth of the Si due to the implantation process was also studied. © 1991.