Thin films of SrTiO3 were homo-epitaxially grown onto Nb-doped SrTiO3 substrates under varying O pressures, and the effect of the O vacancy concentration upon the dielectric properties of the thin films was studied. Although thin films with a low O vacancy concentration exhibited a low zero-bias permittivity, low dielectric tunability and high dielectric dissipation, they could withstand a high electric field. While thin films with a high O vacancy concentration exhibited reduced dielectric loss and high dielectric tunability, they exhibited a low breakdown electric field. In order to make use of these complementary advantages of thin films having different O vacancy concentrations, a trilayered structure was obtained by varying the O pressure during deposition and by combining one thin SrTiO3 layer, having a high O-vacancy concentration, sandwiched between 2 thin films having a low O-vacancy concentration. X-ray diffraction analysis indicated that the trilayer was a relaxed SrTiO3 multilayer made up of 2 thin layers having different lattice parameters.

Dielectric Properties of Multilayered SrTiO3 Thin Films with Graded Oxygen Vacancy Concentration. X.Z.Liu, Y.R.Li: Applied Physics A, 2006, 83[1], 67-72