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

Abstract

Dielectric properties and ac electrical conductivity of the Al/SiO 2/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 ( σ ac) 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 σ ac 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.