Characteristics of (Ba, Sr)TiO3 Capacitors with Textured Ru Bottom Electrode

Ru films were fabricated by dc magnetron sputtering in an Ar/O2 mixture ambient in order to examine the Ru films as electrodes of Ba0.5Sr0.5TiO3 (BST) thin-film capacitors. The 100-nm-thick Ru film deposited on Si at 450?C at an O2/(Ar+O2) flow ratio of 40% at 0.5 kW was textured along c-axis. The full-width at half maximum (FWHM) of 3.14? was obtained for the Ru (002) diffraction peak in an X-ray diffraction (XRD) pattern. BST films deposited on the Ru bottom electrode were also textured along (110). The relative dielectric constant of BST films increased with a decrease in the FWHM of BST (110). The relationship between electrical properties of Ru/BST/Ru capacitors and the orientation of the Ru bottom electrode and BST films was also investigated.