The investigation of frequency dependent electrical characteristics at Al/p-Si Schottky diodes with a native insulator layer

The current-voltage (I-V) characteristics of Al/p-Si Schottky diodes with the native interfacial insulator layer (SiO2) were measured at room temperature. The density of interface states (Nss) distribution profile as a function of (Ess- Ev) was extracted from the forward bias I-V measurements by taking into account the bias dependence of the effective barrier height (e). In addition the capacitance-voltage (C-V) and conductance-voltage (G-V) measurements are studied at frequency range of 10 kHz to 1 MHz. The excess capacitance was observed to decrease with increasing frequency. Such behavior of excess capacitance has been attributed to the fact that the apparent density of Nss decreases with increasing frequency. Experimental results show that the I-V, C-V and G-V characteristics of Schottky Diodes are affected not only in Nss but in also series resistance (Rs), and the location of Nss and Rs have a significant role on electrical characteristics of Schottky diodes.