Annealing temperature effect on electrical characteristics of Co/p-type Si Schottky barrier diodes

Abstract

The electrical characteristics of Co/p-type Si Schottky barrier diodes (SBDs), which were formed at various annealing temperatures from 200 to 600 degrees C, were investigated using current-voltage (I-V) techniques. The Schottky barrier height at 200 degrees C annealing temperature was found to be 0.708 eV (I-V). However, the Schottky barrier height of the Co/p-type Si diode slightly decreases to 0.696 eV (I-V) when the diode was annealed at 300 degrees C for 5 min in N-2 atmosphere. It is noted that the Schottky barrier height increased to 0.765 eV at 400 degrees C, 0.830 eV at 500 degrees C and 0.836 eV at 600 degrees C for 5 min in N2 atmosphere. This increase was attributed to that the annealing removes the passivation effect of the native oxide layer and reactivates the surface defects which are responsible for the Fermi level pinning. Norde method was also used to extract the barrier height of Co/p-type Si Schottky barrier diodes and the values are 0.704 eV for the 200 degrees C, 0.714 eV at 300 degrees C, 0.80447 eV at 400 degrees C, 0.874 eV at 500 degrees C and 0.874eV at 600 degrees C which are in good agreement with those obtained by the I-V method. (C) 2009 Elsevier B.V. All rights reserved.