Improved electrical properties after post annealing of Ba0.7Sr0.3TiO3 thin films for MIM capacitor applications

Dielectric measurements have been performed on ion beam sputtering (IBS) barium strontium titanate Ba 0.7 Sr 0.3 TiO 3 thin films at annealing temperatures 470 and 700 °C using impedance spectroscopy. The effect of the annealing temperature upon the electrical properties of the films is also investigated using capacitance–voltage techniques. Increasing annealing temperature suggested the increases of density and grain size, whereas the density of the trapped oxygen vacancy may be decreasing with increasing annealing temperature. The barrier height ( E a ) of the oxygen vacancy decreases with increasing annealing temperature. The C – V characteristics were investigated in relation to the annealing temperature to identify the anomalous capacitance in the MIM configuration films. Among all measurement temperatures, it was observed that the data fit well by the “LGD” model. The interfacial effect and its dependence of morphology structure have been studied, and the results are discussed.