Author(s)

Oleksandr Khorkhordin, Chia-Pin Yeh, Bodo Kalkofen, Edmund Burte

Institute of Micro and Sensor Systems, Otto von Guericke University, Magdeburg, Germany.

Ferroelectric SrBi₂Ta₂O₉-(Bi₄Ti₃)_1-xNb_xO₁₂ (x = 0.02) (SBT-BTN) multilayer thin films with various stacking periodicity have been synthesized on Ir/Ti/SiO₂/Si substrate by metal organic chemical vapor deposition technique (MOCVD). Tributylbismuth [Bi(C₄H₉)₃], Strontium-bis[Tantal(pentanethoxy)(2-methoxyethoxid)] [Sr[Ta(OEt)₅(OC₂H₄OMe)]₂], Titanium Bis(isopropoxy)bis(1-methoxy-2-methyl-2-propoxide) [Ti(OiPr)₂(mmp)₂] and Niob-ethoxide [Nb(OC₂H₅)₅] were selected as precursors. X-ray diffraction patterns show that the multilayer films annealed at 800^oC consist of fully formed perovskite phase with polycrystalline structure and plate-like grains with no crack. The remanent polarization () and coercive field (Ec) are 16.2 μC/cm² and 230 kV/cm, respectively, which is much higher, compared to pure SBT film ( = 6.4 μC/cm², Ec = 154 kV/cm). In the films prepared above 700^oC, postannealing increased the capacitor shorting rate; this was attributed to oxidizing of the top iridium layer. In this paper, the dependence of composition variation around stoichiometric on ferroelectric properties in SBT-BTN multilayer films is studied.

Ferroelectric, SBT, BTN, MOCVD, Multilayer

Khorkhordin, O. , Yeh, C. , Kalkofen, B. and Burte, E. (2015) Enhanced Ferroelectric Properties of Multilayer SBT-BTN Thin Films for NVRAM Applications. Journal of Crystallization Process and Technology, 5, 49-57. doi: 10.4236/jcpt.2015.54007.