Kinetics, stoichiometry, morphology, and current drive capabilities of Ir-based silicides

A detailed study of the formation of iridium silicide obtained by ultrahigh vacuum annealing and atmospheric rapid thermal processing is proposed using x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and electrical characterizations. Using XPS analysis, the stoichiometry of each silicide phase (IrSi, Ir Si 1.6 ) is identified. A model based on the variation of the measured intensity of the Ir 4 f spectra is used to obtain the kinetic coefficients of reaction of Ir silicidation ( E A = 2.48 eV , D 0 = 9 cm 2 ∕ s ). TEM cross sections indicate that the roughness of the silicide∕silicon interface increases with temperature. Lastly, electrical characteristics are used to identify the optimum annealing temperature to obtain an iridium silicide contact with the lowest Schottky barrier height to holes.