Characterization of NH3 plasma-treated Ba0.7Sr0.3TiO3 thin films
Abstract The effects of plasma surface treatment, using NH 3 gas, of Ba 0.7 Sr 0.3 TiO 3 (BST) films on the leakage and dielectric characteristics of a Pt/BST/Pt capacitor were investigated. As a result of the exposure of BST to the plasma, the leakage current density of the BST capacitor can be improved by three orders of magnitude as compared to that of the non-plasma-treated sample at an applied voltage of 1.5 V. Nevertheless, the surface morphology of BST was also changed by the NH 3 plasma, as explored by atomic force microscopy. From the X-ray photoelectron spectroscopy examination, the existence of the N 1 s peak was observed in the plasma-treated sample. It induces the additional space charge and results in the reduction of the dielectric constant.