Temperature-dependent current-voltage characteristics of Er-silicide Schottky contacts to strained Si-on-insulator

We fabricated Er-silicide (ErSi_1.7) Schottky contacts to strained Si-on-insulator (sSOI) with a strain level of 0.77% and investigated their electrical properties in the temperature range of 225-400 K. The Schottky parameters such as the barrier height, ideality factor, and series resistance were found to strongly depend on temperature. Barrier height and ideality factor were found to decrease and increase, respectively, with decreasing temperature. The series resistance gradually increased with decreasing temperature. A discrepancy between the Schottky barrier heights calculated from the forward current-voltage (I-V) characteristics and Norde's method indicated a deviation from the ideal thermionic emission of ErSi_1.7/sSOI Schottky diode. The lateral inhomogeneity of the Schottky barrier and potential fluctuations at the interface between ErSi_1.7 and sSOI could be a main cause of the difference between the calculated and theoretical values of the Richardson constant. On the basis of a thermionic emission mechanism with a Gaussian distribution of the barrier heights, temperature dependency of ErSi _1.7 Schottky contact to sSOI was explained in terms of the barrier height inhomogeneities at the interface.