Abstract :
The current–voltage (I–V) measurements on Ag/p-Si Schottky barrier diodes in the temperature range 125–300 K were
carried out. The I–V analysis based on the thermionic emission (TE) theory has revealed an abnormal decrease of apparent
barrier height and increase of ideality factor at low temperature. It is demonstrated that these anomalies result due to the barrier
height inhomogeneities prevailing at the metal–semiconductor interface. A Fb0 versus q=2kT plot was drawn to obtain evidence
of a Gaussian distribution of the barrier heights, and values of Fb0 ¼ 0:780 eV and ss0 ¼ 0:0906 V for the mean barrier height
and standard deviation at zero bias have been obtained from this plot, respectively. Furthermore, the mean barrier height and the
Richardson constant values were obtained as 0.773 eV and 15.53 A K 2 cm 2, respectively, by means of the modified
Richardson plot, lnðI0=T2Þ ðq2s2
s0=2k2T2Þ versus 1000/T. Thus, it has been concluded that the temperature dependence
of the I–V characteristics of the Schottky barrier on p-type Si can be successfully explained on the basis of thermionic emission
mechanism with Gaussian distribution of the barrier heights. Moreover, the value of the Richardson constant was found to be
15.53 A K 2 cm 2, which is close to the theoretical value of 32 A K 2 cm 2 used for the determination of the zero-bias barrier
height.
# 2004 Elsevier B.V. All rights reserved
