Compounds and microstructures of silicon-implanted nickel

Abstract

During ion implantation the phase stability and implanted ion composition are strongly affected by the radiation damage inherent in the process. A study was made of the role of radiation damage processes in the implantation of silicon into nickel at temperatures from 25 to 650 °C. Radiation-induced segregation occurred, resulting in a greatly enriched silicon content on substrate surfaces. The crystalline nickel silicide phases, Ni 5Si 2, Ni 2Si and NiSi 2, were observed over a wide temperature range, including T < 200 °C. The Ni 3Si phase, however, was destabilized by radiation damage and formed only at T > 500 °C. At T > 250 °C and fluences near or exceeding 1 × 10 18 Si + cm −2, the implanted layer recrystallized. Penetration of implanted silicon several thousand ångströms beyond the ballistic range of the implanted ions was also observed at these fluences for T > 350 °C. A microcrystalline phase formed in this fluence range at T < 200 °C.