Interface effects in titanium and hafnium Schottky barriers on silicon

Abstract

The effect of Si surface contaminants present prior to metal deposition, and that of post-metalization anneals has been investigated for Ti and Hf Schottky barriers on Si. These diodes have been prepared in ultrahigh vacuum, characterized with Auger spectroscopy and measured in situ using internal photoemission, and ex situ using current-voltage measurements. Although barriers to p-type Si as high as 0.9 eV have been reported in the literature for these metals, barriers of 0.72 eV were the highest observed in this investigation, for surfaces contaminated with significant amounts of oxygen.