Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2005; 47(9(2)): 247

Published online September 30, 2005

Copyright © The Korean Physical Society.

Electrical Properties of ZrO2 and YSZ Films Deposited by Pulsed Laser Deposition

S.H. Kim, I.S. Byun, I.R. Hwang, J.-S. Kim, J.S. Choi, S.-H. Kim, S.H. Jeon, S.H. Hong, J.H. Lee, B.H. Park, S. Seo, M.J. Lee, D.H. Seo, Y.S. Jung, D.-S. Suh, J.E. Lee, I.K. Yoo


Polycrystalline ZrO$_{2}$ and yttria-stabilized ZrO$_{2}$ thin films have been deposited on Pt/Ti/SiO$_{2}$/Si %%@ substrates by pulsed-laser-deposition methods. Pt/ZrO$_{2}$/Pt and Pt/YSZ/Pt capacitor structures show giant conductivity switching %%@ behaviors which can be utilized for nonvolatile memory devices. Maximum on/off ratio of $10^{6}$ and good endurance even after %%@ $10^{5}$ times conductivity switching are observed in a typical Pt/ZrO$_{2}$/Pt whose ZrO$_{2}$ film has been deposited at $100~^{circ}mathrm{C}$ and at an oxygen pressure of 50 mTorr. The Pt/ZrO$_{2}$/Pt structure exhibits two ohmic behaviors in the low-voltage %%@ region (V $<$ 1.4 V), depending on the value of previously applied high voltage, and Schottky-type conduction in the high-voltage region (1.4 %%@ V $<$ V $<$ 8.9 V). It seems that conductivity switching behaviors in our Pt/ZrO$_{2}$/Pt structure result from changes in both the %%@ Schottky barrier and the bulk conductivity controlled by applied voltages. A Pt/YSZ/Pt capacitor structure has more stable %%@ reset voltage and current state than a Pt/ZrO$_{2}$/Pt capacitor structure. Moreover, a Pt/YSZ/Pt capacitor structure shows higher %%@ conductivity than a Pt/ZrO$_{2}$/Pt capacitor structure, which may result from substitution of Y$^{3+}$ ions for Zr$^{4+}$ ions.