Dielectric properties and ac electrical conductivity studies of MIS type Schottky diodes at high temperatures

Dielectric properties and ac electrical conductivity of the Al/SiO2/p-Si (MIS) Schottky diodes were studied in the frequency and temperature range of 10 kHz–1 MHz and 300–400 K, respectively. Experimental results show that the dielectric constant (ε′), dielectric loss (ε″), loss tangent (tan δ), ac electrical conductivity (σac) and the electric modulus were found a strong function of frequency and temperature. The values of the ε′, ε″ and tan δ decrease with increasing frequencies due to the interface states capacitance and a decrease in conductance with increasing frequency. Also, these values increase with increasing temperature. The σac is found to increase with increasing frequency and increasing temperature. The variation of conductivity as a function of temperature and frequency reveals non-adiabatic hopping of charge carriers between impurities localized states. In addition, the experimental dielectric data have been analyzed by considering electric modulus formalism.