Bi 2 Ti 2 O 7 thin films were grown by radio-frequency magnetron sputtering on bare and Pt-coated sapphire substrates at low substrate temperatures (∼200 °C). Postdeposition anneals were carried out at different temperatures to crystallize the films. Nearly phase-pure Bi2Ti2O7 thin films with the cubic pyrochlore structure were obtained at annealing temperatures up to 800 °C. Impurity phases, in particular Bi4Ti3O12, formed at higher temperatures. At 1 MHz, the dielectric constants were about 140–150 with a very small tunability and the dielectric loss was about 4×10−3. The dielectric loss increased with frequency. The dielectric properties of Bi2Ti2O7 films are compared to those of pyrochlore bismuth zinc niobate films.

The letter reports on the dielectric losses of differently textured SrTiO 3 films on Pt bottom electrodes at frequencies between 1 MHz and 1 GHz. Device parasitic contributions to the measured device losses were partially removed by measuring shorted devices. Different dielectric loss mechanisms were identified. These included strongly frequency dependent loss peaks and a low temperature loss increase that showed a power-law dependence on the bulk permittivity of the films. Possible origins of the different loss mechanisms are discussed.

Dielectric measurements as a function of temperature were used to characterize the properties of the dielectric dead layers in parallel-plate capacitors with differently textured SrTiO3 thin films and Pt electrodes. The apparent thickness dependence of the permittivity was described with low-permittivity passive (dead) layers at the interfaces connected in series with the bulk of the SrTiO3 film. Interfacial capacitance densities changed with the film microstructure and were weakly temperature dependent. Estimates of the dielectric dead layer thickness and permittivity were limited by the film surface roughness (∼5nm). The consequences for the possible origins of dielectric dead layers that have been proposed in the literature are discussed.

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We report on some of the key properties of ferroelectric and high-permittivity thin films relevant for their application in metal/insulator/metal structures, such as voltage tunable capacitors and novel memories. We use a model system, Pt/SrTiO 3 /Pt thin film structures, with microstructures, stress states and point defects characterized by advanced transmission electron microscopy techniques, high-resolution x-ray diffraction and wafer curvature measurements. We investigate the relation between defects and dielectric properties, measured at frequencies up to 1 GHz. We discuss the origins of dielectric losses in these films and the role of point defects, such as oxygen vacancies. We report on dielectric deadlayers, which cause a significant reduction in the dielectric tunabilities. We discuss the influence of dielectric relaxation on the thermal leakage characteristics of textured and epitaxial Pt/SrTiO 3 /Pt thin film structures. We also discuss the properties of Pt/SrTiO 3 /Pt structures with ultrathin (5 -10 nm) SrTiO 3 films.