Effects of the Interfacial Layers on the Time-Dependent Leakage Current Characteristics of(Ba,Sr)TiO3 Thin Films

Abstract

Current-voltage characteristics and time-dependent leakage current behavior of(Ba,Sr)TiO3 (BST) thin films deposited by rf magnetron sputtering have been studied in order to identify the effects of interfacial lavers between bottom electrodes and BST thin films on the leakage properties of BST capacitors. Two different methods were used to modify the interfacial layers. One is the 2-step deposition of BST thin films and the other is the preparation of BST films on various bottom electrodes of RuO2, Pt and Pt/RuO2 hybrid layers. From a comparison of time-dependent electrical properties of the BSTcapacitors prepared by the 2-step deposition method with the various bottom electrodes, it was concluded that the oxygen vacancies in the interfacial layer between BST films and the bottom electrodes are responsible for the observed time-dependent leakage properties.