Thickness effects on the electrical characteristics of Ba0.7Sr0.3TiO3 capacitors with nano-Cr interlayer

Abstract

A multilayer Ba0.7Sr0.3TiO3/Cr/Ba0.7Sr0.3TiO3 (BST/Cr/BST) structure was sputtered sequentially onto Pt/Ti/SiO2/Si substrate. With the insertion of a 2 nm Cr interlayer, the temperature coefficient of capacitance of the BST/Cr/BST dielectric is about 69% lower than that of BST monolayer dielectric. The dielectric constant and dissipation factor as the function of Cr thickness are studied. X-ray diffraction patterns, the analysis results of energy dispersive spectroscopy, and the survey scan profiles of Auger electron spectroscopy reveal the formation of a TiO2 secondary phase after the multilayer is annealed at 800 degrees C in O-2 atmosphere. The insertion of nano-Cr interlayer improves the electrical properties of BST capacitors. (c) 2007 American Institute of Physics.