Analysis of interface states and series resistance of MIS Schottky diodes using the current–voltage ( I– V) characteristics

Abstract

The purpose of this paper is to analyze interface states in Al/SiO 2/p-Si (MIS) Schottky diodes and determine the effect of SiO 2 surface preparation on the interface state energy distribution. The current–voltage ( I– V) characteristics of MIS Schottky diodes were measured at room temperature. From the I– V characteristics of the MIS Schottky diode, ideality factor ( n) and barrier height (Φ B) values of 1.537 and 0.763 eV, respectively, were obtained from a forward bias I– V plot. In addition, the density of interface states ( N ss) as a function of ( E ss– E v) was extracted from the forward bias I– V measurements by taking into account both the bias dependence of the effective barrier height (Φ e), n and R s for the MIS Schottky diode. The diode shows non-ideal I– V behaviour with ideality factor greater than unity. In addition, the values of series resistance ( R s) were determined using Cheung’s method. The I– V characteristics confirmed that the distribution of N ss, R s and interfacial insulator layer are important parameters that influence the electrical characteristics of MIS Schottky diodes.