Effect of series resistance on the performance of silicon Schottky diode in the presence of tin oxide layer

The current–voltage (I–V) characteristics of Al/SnO2/p-Si (MIS) Schottky diodes prepared by means of spray deposition method have been measured at 80, 295 and 350 K. In order to interpret the experimentally observed non-ideal Al/SnO2/p-Si Schottky diode parameters such as, the series resistance Rs, barrier height FB and ideality factor n, a novel calculation method has been reported by taking into account the applied voltage drop across interfacial oxide layer Vi and ideality factor n in the current transport mechanism. The values obtained for Vi were subtracted from the applied voltage values Vand then the values of Rs were recalculated. The parameters obtained by accounting for the voltage drop Vi have been compared with those obtained without considering the above voltage drop. It is shown that the values of Rs estimated from Cheung’s method were strongly temperature-dependent and decreased with increasing temperature. It is shown that the voltage drop across the interfacial layer will increase the ideality factor and the voltage dependence of the I–V characteristics. The interface state density Nss of the diodes has an exponential growth with bias towards the top of the valance band for each temperature; for example, from 2.37 1013 eV 1 cm 2 in 0.70 Ev eV to 7.47 1013 eV 1 cm 2 in 0.62 Ev eV for 295 K. The mean Nss estimated from the I–V measurements decreased with increasing the temperature from 8.29 1013 to 2.20 1013 eV 1 cm 2.