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 almost-equal-to 130 keV. Doses of the Ir ions ranging from 2 x 10(16) to 1.5 x 10(17)/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-degrees-C. A continuous IrSi3 layer of almost-equal-to 200 angstrom thick buried under almost-equal-to 400 angstrom of Si was achieved with samples implanted with doses not less than 3.5 x 10(16)/cm2. Implanted doses above 8 x 10(16)/cm2 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.