Comparison of Dielectric Characteristics of Ta[sub 2]O[sub 5] Thin Films on RuO[sub 2] and Ru Bottom Electrodes

Dielectric properties of thin films with and Ru as the bottom electrodes were investigated. The thin films were reactively sputtered on the bottom electrodes and then annealed in oxygen ambient at for 30 min. Using X-ray diffraction and Auger electron spectrometry, it has been found that the Ru bottom electrode was partially oxidized during annealing, while the electrode remained its structure. However, the annealed exhibited a higher dielectric constant, as well as a smaller leakage current, on the Ru electrode than on the electrode. Accordingly, the Ru bottom electrode is satisfactory for storage capacitors, even in a high temperature, oxidizing environment. The divergent electrical performances of two electrodes are attributed to the different crystallinity of annealed on Ru and © 2001 The Electrochemical Society. All rights reserved.