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Fatigue Characteristics of PZT Thin Films Deposited by ECR-PECVD

  • Chung, Su-Ock (Department of Materials Science and Engineering, KAIST) ;
  • Lee, Won-Jong (Department of Materials Science and Engineering, KAIST)
  • 발행 : 2005.08.01

초록

Fatigue characteristics of lead zirconate titanate (PZT) films deposited by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) were investigated. The fatigue characteristics were investigated with respect to PZT film thickness, domain structure, fatigue pulse height, temperature, electrode materials and electrode configurations. The used top and bottom electrode materials were Pt and $RuO_2$. In the fatigue characteristics with fatigue pulse height and PZT film thickness, the fatigue rates are independent of the applied fatigue pulse height at the electric field regions to saturate the P-E hysteresis and polarization $(P^*,\;P^A)$ characteristics. The unipolar and bipolar fatigue characteristics of PZT capacitors with four different electrode configurations $(Pt//Pt,\;Pt//RuO_2,\;RuO_2//Pt,\;and\;RuO_2//RuO_2)$ were also investigated. The polarization-shifts during the unipolar fatigue and the temperature dependence of fatigue rate suggest that the migration of charged defects should not be expected in our CVD-PZT films. It seems that the polarization degradations are attributed to the formation of charged defects only at the Pt/PZT interface during the domain switching. The charged defects pin the domain wall at the vicinity of Pt/PZT interface. When the top and bottom electrode configurations are of asymmetric $(Pt//RuO_2,\;RuO_2//Pt)$, the internal fields can be generated by the difference of charged defect densities between top and bottom interfaces.

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참고문헌

  1. H. M. Duiker, P. D. Beale, J. F. Scott, C. A. paz de Araujo, B. M. Melnick, J. D. Cuchioaro, and L. D. McMillan, 'Fatigue and switching in ferroelectric memories: Theory and experiment', J. Appl. Phys, Vol. 68, No. 11, p. 5783, 1990
  2. W. L. Warren, D. Dimos, B. A. Tuttle, R. D. Nasby, and G. E. Pike, 'Electronic domain pinning in Pb(Zr,Ti)$O_3$ thin films and its role in fatigue', Appl. Phys. lett., Vol. 65, No.8, p. 1018, 1994 https://doi.org/10.1063/1.112211
  3. X. Du and I. W. Chen, 'Fatigue of $Pb(Zr_{0.53}Ti_{0.47})0_3$ ferroelectric thin films', J. Appl. Phys., Vol. 83, No. 12, p. 7789, 1998
  4. T. Hase, T. Noguchi, K. Takenura, and Y. Miyasaka, 'Imprint characteristics of $SrBi_2Ta_2O_9$ thin films with modified Sr composition', Jpn. J. Appl. Phys., Vol. 37, No. 9B, p. 5198, 1998
  5. D. Ricinschi and M. Okuyama, 'Relationships between macroscopic polarization hysteresis and local piezoresponse of fatigued Pb(Zr,Ti)$O_3$ films within a Landau theory-based lattice model', Appl. Phys. Lett., Vol. 81, No. 21, p. 4040, 2002
  6. A. Jiang, M. Dawber, J. F. Scott, C. Wang, P. Migliorato, and M. Gregg, 'Studies of switching kinetics in ferroelectric thin films', Jpn. J. Appl. Phys., Vol. 42, No. 11, p. 6973, 2003
  7. B. S. Kawk, E. P. Boyd, and A. Erbil, 'Metalorganic chemical vapor deposition of $PbTiO_3$ thin films', Appl. Phys. Lett., Vol. 53, No. 18, p. 1702, 1988 https://doi.org/10.1063/1.100341
  8. S. O. Chung, J. W. Kim, S. T. Kim, G. H. Kim, and W. J. Lee, 'Microstructure and electric properties of the PZT thin films fabricated by ECR PECVD: the effects of an interfacial layer and rapid thermal annealing', Mat. Chem. & Phys., Vol. 53, No.1, p. 60, 1998
  9. S. O. Chung, H. C. Lee, and W. J. Lee, 'Effects of electrodes on the electric properties of Pb(Zr,Ti)$O_3$ films deposited by electron cyclotron resonance plasma enhanced chemical vapor deposition', Jpn. J. Appl. Phys., Vol. 39, No. 3A, p. 1203, 2000 https://doi.org/10.1143/JJAP.39.1203
  10. K. M. Byun, J. W. Kim, and W. J. Lee, 'Theoretical composition calibration and thickness measurement in the analysis of multielement thin films using wavelength dispersive spectroscopy: applications to lead zirconate titanate thin films', Jpn. J. Appl. Phys., Vol. 36, No. 9AB, p. L1242, 1997
  11. S. O. Chung, J. W. Kim, G. H. Kim, C. O. Park, and W. J. Lee, 'Formation of a lead zirconate titanate (PZT)/Pt interfacial layer and structural changes in the Pt/Ti/$SiO_2$/Si substrate during the deposition of PZT thin film by electron cyclotron resonance plasma-enhanced chemical vapor deposition', Jpn. J. Appl. Phys., Vol. 36, No. 7A, p. 4386, 1997
  12. H, Funakubo, T. Hioki, M. Otsu, K. Shinizaki, and N. Mizutani, 'Film thickness dependence of dielectric property and crystal structure of $PbTiO_3$ film prepared on Pt/$SiO_2$/Si substrate by metal organic chemical vapor deposition', Jpn. J. Appl. Phys., Vol. 32, No. 9B, p. 4175, 1993
  13. T. Tsurumi, Y. Kumano, N. Ohashi, T. Takenaka, and O. Fukunaga, '90$^{\circ}$ domain reorientation and electric-field-induced strain of tetragonal lead zirconate titanate ceramics', Jpn. J. Appl. Phys., Vol. 36, No. 9B, p. 5970, 1997