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 5.41×10-3 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.