Temperature dependent current-voltage and capacitance-voltage characteristics of chromium Schottky contacts formed by electrodeposition technique on n-type Si

Abstract

The variations in the electrical properties of Cr Schottky contacts formed by electrodeposition technique on n-type Si substrate have been investigated as a function of temperature using current-voltage (I-V) and capacitance-voltage (C-V) measurements in the temperature range of 80-320 K by steps of 20 K. The basic diode parameters such as ideality factor (n) and barrier height (Φb) were consequently extracted from the electrical measurements. It has been seen that the ideality factor increased and the barrier height decreased with decreasing temperature, when the I-V characteristics were analyzed on the basis of the thermionic emission (TE) theory. The abnormal temperature dependence of the Φb and n and is explained by invoking two sets of Gaussian distribution of barrier heights at 320-200 K, and 180-80 K. The double Gaussian distribution analysis of the temperature-dependent I-V characteristics of the Cr/n-type Si Schottky contacts gave the mean barrier heights of 0.910 and 0.693 eV and standard deviations (σs) of 109 mV and 72 mV, respectively. Then, these values of the mean barrier height have been confirmed with the modified ln(I 0/T2) - q2/2k2T2 versus 1/T plot which belongs the two temperature regions. © 2011 Elsevier B.V. All rights reserved.