Temperature dependence of electrical characteristics of Cr/p-Si(100) Schottky barrier diodes

Abstract

The electrical characteristics of Cr/p-Si(100) Schottky barrier diodes have been measured in the temperature range of 100-300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41 x 10(-3) Acm(-2)K(-2) is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm(-2)K(-2) for p-type Si. It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p-Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.