Current‐voltage characteristics and composition profiles of Ni‐Pt silicide Schottky diodes

摘要

The forward current‐voltage (If‐Vf) characteristics of (50 wt Ni– 50 wt Pt) silicide Schottky diodes, formed in vacuum at 425 °C from rf sputter‐deposited Ni and Pt thin films, were found to be dependent on the metal‐deposition sequence. From the thermionic emission equation an empirical barrier height of 0.70 eV was calculated for diodes formed from 125 A˚ Pt/325  A˚ Ni/(111) Si, while diodes formed from 325 A˚ Ni/125A˚ Pt/(111) Si had an empirical barrier height of 0.65 eV. The deposition of a thin W‐Ti diffusion marker film on the Si surface before sputter deposition of Ni and Pt layers modifiedIf‐Vfcharacteristics. Silicide diodes formed from 125 A˚ Pt/325 A˚ Ni/(W‐Ti)/(111) Si had an empirical barrier height of 0.66 eV. Diodes formed from 325 A˚ Ni/125 A˚ Pt/(W‐Ti)/(111) Si had an empirical barrier height of 0.70 eV. MeV4He+backscattering spectra revealed that diodes with similarIf‐Vfcharacteristics had similar Ni and Pt concentration profiles in the silicide film.