Electrical Properties of Sol–Gel Deposited BaTiO3 Thin Films on Si(100) Substrates

Abstract

The electrical properties of sol–gel deposited BaTiO3 thin films on Si(100) and SiO2-buffered Si(100) substrates were investigated. The dielectric constant measured as a function of frequency was fitted using the space charge relaxation model. The effective dielectric constant (ε') and dissipation factor (tan δ) were determined in the accumulation region from the results of capacitance–voltage ( C–V ) measurements at room temperature, at 1 MHz. Values of 23–185 and 0.02–0.08 were determined, respectively. The density of the interfacial surface states (N ss), calculated from the width of the memory window of the C–V curve, was of the order of 1011–1012 eV-1 cm-2. The leakage current densities for BaTiO3 films deposited on Si and SiO2-buffered Si substrates were 22–57 nA/ cm2 and 0.85–4 nA/ cm2, respectively, at an applied field of 100 kV/cm. The dielectric breakdown strength exceeded 1 MV/cm for all films.