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

The electrical characteristics of Co/p-type Si Schottky barrier diodes (SBDs), which were formed at various annealing temperatures from 200 to 600 °C, were investigated using current–voltage (I–V) techniques. The Schottky barrier height at 200 °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 °C for 5 min in N2 atmosphere. It is noted that the Schottky barrier height increased to 0.765 eV at 400 °C, 0.830 eV at 500 °C and 0.836 eV at 600 °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 °C, 0.714 eV at 300 °C, 0.80447 eV at 400 °C, 0.874 eV at 500 °C and 0.874 eV at 600 °C which are in good agreement with those obtained by the I–V method.