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 FWHM of 3.14 degrees was obtained for the Ru (002) diffraction peak in an 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. 15 refs.