Thickness dependence of microstructure, dielectric and leakage properties of BaSn0.15Ti0.85O3 thin films

The BaSn0.15Ti0.85O3 (BTS) thin films are prepared on Pt-Si substrates with thickness ranging from ~ 60 nm to ~ 380 nm by radio frequency magnetron sputtering. The effects of thickness on microstructure, surface morphologies and dielectric properties of thin films are investigated. The thickness dependence of dielectric constant is explained based on the series capacitor model that the BTS thin film is consisted by a BTS bulk layer and an interfacial layer (dead layer) between the BTS and bottom electrode. The thin films with thickness of 260 nm give the largest figure of merit of 76.9@100 kHz, while the tunability and leakage current density are 64.6% and 7.46 × 10−7 A/cm2 at 400 kV/cm, respectively.