Characteristics of Ba0.8Sr0.2TiO3 ferroelectric thin films by RF magnetron sputtering

Ferroelectric Ba0.8Sr0.2TiO3 (BST) thin films were deposited on Pt/Ti/SiO2/Si substrates via a modified RF magnetron sputtering by introducing the revolution of workholders. X-ray diffraction, Auger electron spectroscopy, atomic force microscope and electrical measurements were used to characterize BST thin films annealed at different temperatures. Smooth and dense surface with homogeneous grains (about 80 nm) was observed. The electrical measurement results showed BST films annealed at 650 °C have higher dielectric constant, lower loss tangent, lower leakage current and higher breakdown voltage. The curves of the temperature dependence of dielectric constant in different frequencies exhibit Curie transition at temperature around 19 °C. The remnant polarization and the coercive field are 4.1 μC/cm2 and 60.9 kV/cm, respectively. This work clearly reveals the highly promising potential of BST thin films for application in uncooled infrared focal plane arrays.