On the dielectric characteristics of Au/SnO2/n-Si capacitors

Dielectric responses of Au/SnO2/n-Si capacitors have been investigated. C-V and G-V measurements were performed in the voltage range −6-+8 V and the frequency range from 500 to 10 MHz. The SnO2 oxide layer thickness of 400 Å between metal and semiconductor was calculated from the measurement of the oxide capacitance in the strong accumulation region. The dielectric constant ε′, imaginary part of dielectric constant ε″, dielectric loss tangent tan δ and AC conductivity σAC were calculated from the C-V and G-V measurements and plotted as a function of frequency and voltage. Experimental results show that the ε′, ε″, and tan δ are found to decrease with increasing frequency while σAC is increased. The interfacial polarization can be more easily occurred at low frequencies, and the number of interface state density between SnO2/Si interfaces. Consequently, it contributes to the improvement of dielectric properties of Au/SnO2/n-Si (1 1 1) Schottky structure.