A CONTACT MODEL FOR POISSON-BASED SPREADING RESISTANCE CORRECTION SCHEMES INCORPORATING SCHOTTKY-BARRIER AND PRESSURE EFFECTS

Accurate determination of the electrically active dopant profile from spreading resistance measurements requires the application of a carrier spilling correction scheme based on the iterative solution of the one-dimensional Poisson-Boltzmann equation. It will be shown that the results are strongly influenced by the boundary conditions applied describing the probe-silicon contact. An exploratory and somewhat speculative new theoretical probe contact model will be presented which takes into account Schottky barrier effects, surface states on the bevel surface, band-gap narrowing and variations of the dielectric constant due to the large probe pressures applied at the metal-silicon interface. It will be shown that this model can predict adequately the detailed behavior of an experimentally measured spreading resistance low dose implant.