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Enhanced Ferroelectric Properties of Multilayer SBT-BTN Thin Films for NVRAM Applications

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DOI: 10.4236/jcpt.2015.54007    3,480 Downloads   3,864 Views   Citations

ABSTRACT

Ferroelectric SrBi2Ta2O9-(Bi4Ti3)1-xNbxO12 (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 800oC 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 700oC, 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.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

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.

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