A contact model for Poisson-based spreading resistance correction schemes incorporating Schottky barrier and pressure effects

Abstract

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.