Frequency-Dependent Dielectric Parameters of Au/TiO2/n-Si (MIS) Structure

In this study, thin film of titanium dioxide (TiO 2 ) was deposited onto n-type silicon substrate by radio frequency (RF) magnetron sputtering system. The admittance (capacitance and conductance) measurements were performed in the frequency range of 500 Hz - 500 kHz and at room temperature. The dielectric parameters such as dielectric constant ( ε ′ ), loss ( ε ″ ), loss tangent (tan δ ), ac conductivity ( σ a c ) and complex modulus ( M ∗ ) of the MIS structure were obtained from these measurements. While the C value decreases with an increase of the frequency, the G increases. The change in C and G with frequency is attributed to the presence interface states. The value of ε ′ and ε ″ decreases with increasing frequency. On the other hand, the value of ac conductivity increases with increasing frequency.