Temperature dependence of current-voltage characteristics of Sn/p-Si Schottky contacts

The current-voltage (I-V) characteristics of Sn/p-Si Schottky barrier diode have been measured over a wide range of temperature (80-300 K) and interpreted on the basis of thermionic emission mechanism by merging the concept of barrier inhomogeneities through a Gaussian distribution function. The analysis has revealed an anomalous decrease of apparent barrier height Phi(b0), increase of ideality factor n, and nonlinearity of the activation energy plot at lower temperatures. A Phi(b0) versus 1/T plot has been drawn to obtain evidence of a Gaussian distribution of barrier heights, and values of 0.97 eV and 0.084 V for the mean barrier height Phi(b0) and standard deviation sigma(0) have been obtained, respectively, from this plot. A modified ln(I-0/T-2)-(q(2)sigma(2)/2k(2)T(2)) versus 1/T plot gives Phi(b0) and Richardson constant A** as 0.95 eV and 15.6 A cm(-2) K-2, respectively. It can be concluded that the temperature dependent I-V characteristics of the Sn/p-Si Schottky barrier diode can be successfully explained on the basis of a thermionic emission mechanism with Gaussian distribution of the barrier heights. We have also discussed whether or not the junction current has been connected with thermionic field-emission mechanism. (C) 2007 Elsevier B.V. All rights reserved.