INFLUENCE OF BUFFER LAYERS AND BARRIER METALS ON PROPERTIES OF (BA, SR)TIO3 FILMS PREPARED BY LIQUID SOURCE CHEMICAL-VAPOR-DEPOSITION

The characteristics, especially the electrical properties, of (Ba, Sr) TiO3 [BST] films obtained by a two-step process of liquid source chemi cal vapor deposition (CVD) on two types of substrates or Ru/Si and Ru/ TiN/Ti/Si structures have been investigated. First, the studies on the best deposition conditions for BST buffer layers on Ru/Si substrates indicated that more crystallized buffer layers improved the electrical properties of the two-step-deposited BST films. The reproducibility o f the measured thicknesses was 1.5% (1 sigma) and that for t(eq)-value s of equivalent SiO2 thicknesses was 5.4% (1 sigma) for seven consecut ive two-step runs on Ru/Si substrates. Moreover, the insertion of the barrier metals TiN/Ti between Ru and Si, which was stable enough for b ack-end processing at high temperatures, increased the degree of some crystal orientations of BST and Ru films; however, it hardly changed t he electrical properties of the BST films deposited in two-steps.