Study on the frequency dependence of electrical and dielectric characteristics of Au/SnO2/n-Si (MIS) structures

In this paper, we present a detailed investigation of the electrical and dielectric properties of the Au/SnO2/n-Si (MIS) structures. The capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics have been measured in the frequency range of 1 kHz–1 MHz at room temperature. Calculation of the dielectric constant (ϵ′), dielectric loss (ϵ″), loss tangent (tan δ), ac electrical conductivity (σac), ac resistivity (ρac) and the electric modulus are given in the studied frequency ranges. Experimental results show that the values of dielectric parameters are a strong function of frequency. The decrease of ϵ′ and ϵ″ with increasing frequency were observed. In addition the increase of σac with increasing frequency is founded. Also, electric modulus formalism has been analyzed to obtain the experimental dielectric data. The interfacial polarization can be more easily occurred at the lower frequency and/or with the number of interface state density between SnO2/Si interface, consequently, contribute to the improvement of dielectric properties of MIS structure.