Mesotaxy Layers of IrSi₃ in (111)Si Formed by MeV ION Implantation

Iridium has been implanted at 1MeV and 500keV in the dose range 1 to 3×1017/cm2 at 525°C to form a buried Ir-rich region ∼ 2500Å below the surface in (111)Si. Samples were annealed at temperatures in the range 600°C to 1200°C to form buried IrSi3 layers. Rutherford backscattering and channeling analysis in conjunction with transmission electron microscopy were used to study the formation and the alignment of the IrSi3 layer to the silicon host as a function of annealing. For a dose of 2×1017 Ir/cm2, stoichiometric IrSi3 formed beneath ∼ 2000Å of Si after annealing to 1100°C. The IrSi3 layer was aligned with the Si substrate with Xmin ∼12%, but a band of precipitates remained either side of the main layer.