Effects of Substrate and Annealing Temperatures on the Characteristics of SrBi₄Ti₄O₁₅ Thin Films

Abstract

In this study, radio frequency (RF) sputtering was used as the method and the layerstructured bismuth compound o f SrBi4 Ti4 Ols + 4 wt% Bi2C >3 ferroelectric ceramic was used as the target to deposit the SrBi4 Ti4 Oi5 (SBT) thin films. The addition o f excess Bi20 3 content in the target ceramic was used to compensate the vaporization o fB i20 , during the sintering and deposition processes. SBT ferroelectric thin films were deposited on Pt/Ti/Si02/Si under optimal RF magnetron sputtering parameters with different substrate temperatures fo r 2 h. After that the SBT thin films were postheated using rapid temperature annealing (RTA) method. The dielectric and electrical characteristics o f the SBT thin films were measured using metal-ferroelectric-metal (MFM) structure. From the physical and electrical measurements o f X-ray diffraction pattern, scanning electronic microscope (SEM), I-V curve, and C-V curve, we had found that the substrate temperature and RTA-treated temperature had large influences on the morphology, the crystalline structure, the leakage current density, and the dielectric constant o f the SBT thin films.