Regensburg 2010 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 10: Dielectric surfaces and interfaces

DF 10.8: Vortrag

Mittwoch, 24. März 2010, 16:50–17:10, H11

Energy band alignment between Pb(Zr,Ti)O₃ and high and low work function conducting oxides - from hole to electron injection — •Robert Schafranek¹, Feng Chen¹, Shunyi Li¹, Wenbi Wu², and Andreas Klein¹ — ¹Darmstadt University of Technology, Institute of Materials Science, Surface Science Division, Petersenstrasse 23, D-64287 Darmstadt, Germany — ²Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People’s Republic of China

Metal/oxide interfaces are important for a variety of applications. For example in ferroelectric random access memories based on Pb(Zr,Ti)O₃ (PZT) the fatigue (reduction of the of the polarization with switching cycles) depends substantially on the used electrode material. While for Pt electrodes a fast degradation of the polarization is reported, this effect is not observed for RuO₂ electrodes up to 1012 cycles. The contact properties between Pb(Zr,Ti)O₃ and the high work function conducting oxide RuO₂ respectively the low work function conducting oxide In₂O₃:Sn (ITO) were studied using in situ photoelectron spectroscopy (PES). In an ultra high vacuum system stepwise deposition of RuO₂ and ITO on PZT thin films by magnetron sputtering and interface characterization via PES were carried out without breaking vacuum. From the PES experiments a smaller barrier for the hole injection into PZT is found for RuO₂ while for ITO the injection of electrons is favored.