Scientific journal
Scientific Review. Technical science
ISSN 2500-0799
ПИ №ФС77-57440

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INVESTIGATION OF LEAKAGE CURRENT MECHANISMS IN COMPOSITE NANOMATERIALS BASED ON TA2O5/TIO2 MULTILAYER FILM STRUCTURES

Plotnikov V.V. 1 Drozdovskii A.V. 1 Shishmakova G.A. 2
1 Saint Petersburg Electrotechnical University “LETI”
2 Ferrite Domen Co.
DC reactive magnetron sputtered Ta2O5 (tantalum oxide), TiO2 (titanium oxide) thin films and Ta2O5/TiO2 heterostructures were systematically studied on leakage current mechanisms. Shottky emission, field emission and Fowler-Nordheim tunneling were identified as dominant mechanisms for Ta2O5/TiO2 capacitors. Temperature-dependent current-voltage characteristics suggest thermionic activation of charge carries from Ta2O5/TiO2 hope levels that’s why was observed increasing of leakage current densities with heat treatment. By spectroscopic measurements were found Ta2O5/TiO2 optical properties: refractive index, n ~ 2.2; transmission coefficient, T ~ 70%; optical bandgap, Ebg ~ 4.2 eV. By capacitance-voltage and current-voltage measurements were found Ta2O5/TiO2 dielectric properties: dielectric constant, k ~ 32 for TiO2, 25 for Ta2O5 and 30 for Ta2O5/TiO2; dielectric strength (also known as breakdown voltage), Ebd ~ 2 MV/cm; leakage current density at zero bias, J ~ 10-9 A/cm2.