Abstract
We investigated microstructures, compositional distributions, and electrical properties of dielectric CaCu3Ti4O12 (CCTO) thin films deposited on Pt/TiO2/SiO2/Si substrates from 700 to 800 °C by pulsed laser deposition. With increasing the deposition temperature from 700 to 750 °C, the dielectric constants (εr) of CCTO films were greatly enhanced from ∼300 to ∼2000 at 10 kHz, respectively. However, the εr values of CCTO films were gradually decreased above 750 °C, which was surely attributable to the formation of a TiO2-rich dead layer at the interface between CCTO and Pt electrode. Compositional analyses by Auger electron spectroscopy, energy dispersive spectroscopy, and electron energy loss spectroscopy revealed that the TiO2-rich dead layer became thicker because of severe Cu diffusion from CCTO films to Pt electrode. The leakage current behaviors of CCTO films are in good agreement with Poole–Frenkel conduction mechanism, where both the TiO2-rich dead layer and rutile TiO2 nanocrystalline particles are considered to play a role of charge trapping centers.
Similar content being viewed by others
References
M.A. Subramanian, D. Li, N. Duan, B.A. Reisner, and A.W. Sleight: High dielectric constant in ACu3Ti4O12 and ACu3Ti3FeO12 phases. J. Solid State Chem. 151, 323 (2000).
S.Y. Chung, I.D. Kim, and S.J.L Kang: Strong nonlinear current–voltage behaviour in perovskite-derivative calcium copper titanate. Nat. Mater. 3, 774 (2004).
D.C. Sinclair, T.B. Adams, F.D. Morrison, and A.R. West: CaCu3Ti4O12: One-step internal barrier layer capacitor. Appl. Phys. Lett. 80, 2153 (2002).
T.B. Adams, D.C. Sinclair, and A.R. West: Giant barrier layer capacitance effects in CaCu3Ti4O12 ceramics. Adv. Mater. 14, 1321 (2002).
Y.H. Lin, J. Cai, M. Li, C.W. Nan, and J. He: Grain boundary behavior in varistor-capacitor TiO2-rich CaCu3Ti4O12 ceramics. J. Appl. Phys. 103, 074111 (2008).
T.B. Adams, D.C. Sinclair, and A.R. West: Influence of processing conditions on the electrical properties of CaCu3Ti4O12 ceramics. J. Am. Ceram. Soc. 89, 3129 (2006).
L. Fang, M. Shen, and D. Yao: Microstructure and dielectric properties of pulsed-laser-deposited CaCu3Ti4O12 thin films on LaNiO3 buffered Pt /Ti /SiO2/Si substrates. Appl. Phys. A 80, 1763 (2005).
Y.W. Li, Z.G. Hu, J.L. Sun, X.J. Meng, and J.H. Chu: Effects of LaNiO3 bottom electrode on structural and dielectric properties of CaCu3Ti4O12 films fabricated by sol-gel method. Appl. Phys. Lett. 92, 042901 (2008).
C.C. Homes, T. Vogt, S.M. Shapiro, S. Wakimoto, and A.P. Ramirez: Perovskite-related oxide optical response of high-dielectric-constant. Science 293, 673 (2001).
J. Li, A.W. Sleight, and M.A. Subramanian: Evidence for internal resistive barriers in a crystal of the giant dielectric-constant material: CaCu3Ti4O12. Solid State Commun. 135, 260 (2005).
T.T. Fang and C.P. Liu: Evidence of the internal domains for inducing the anomalously high dielectric constant of CaCu3Ti4O12. Chem. Mater. 17, 5167 (2005).
M.A. Ramirez, P.R. Bueno, R. Tararam, A.A. Cavlheiro, E. Longo, and J.A. Varela: Evaluation of the effect of the stoichiometric ratio of Ca/Cu on the electrical and microstructural properties of the CaCu3Ti4O12 polycrystalline system. J. Phys. D Appl. Phys. 42, 185503 (2009).
S. Krohns, P. Lunkenheimer, S.G. Ebbinghaus, and A. Loidl: Broadband dielectric spectroscopy on single-crystalline and ceramic CaCu3Ti4O12. Appl. Phys. Lett. 91, 022910 (2007).
M.H. Whangbo and M.A. Subramanian: Structural model of planar defects in CaCu3Ti4O12 exhibiting a giant dielectric constant. Chem. Mater. 18, 3257 (2009).
M.C. Ferrarelli, D.C. Sinclair, A.R. West, H.A. Dabkowska, A. Dabkowski, and G.M. Luke: Comment on the origin(s) of the giant permittivity effect in CaCu3Ti4O12 single crystals and ceramics. J. Mater. Chem. 19, 5916 (2009).
W. Si, E.M. Cruz, P.D. Johnson, P.W. Barnes, P. Woodward, and A.P. Ramirez: Epitaxial thin films of the giant-dielectric-constant material CaCu3Ti4O12 grown by pulsed laser deposition. Appl. Phys. Lett. 81, 2056 (2002).
Y. Lin, Y.B. Chen, T. Garret, S.W. Liu, L. Chen, R.P. Bontchev, A. Jacobson, J.C. Jiang, E.I. Meletis, J. Horwitz, and H.D. Wu: Epitaxial growth of dielectric CaCu3Ti4O12 thin films on (001) LaAlO3 by pulsed laser deposition. Appl. Phys. Lett. 81, 631 (2002).
L. Fang and M. Shen: Deposition and dielectric properties of CaCu3Ti4O12 thin films on Pt/Ti/SiO2/Si substrates using pulsed laser deposition. Thin Solid Films 440, 60 (2003).
L. Fang, M. Shen, and W. Cao: Effects of postanneal conditions on the dielectric properties of CaCu3Ti4O12 thin films prepared on Pt/Ti/SiO2/Si substrates. J. Appl. Phys. 95, 6483 (2004).
G. Deng, T. Yamada, and P. Muralt: Evidence for the existence of a metal-insulator-semiconductor junction at the electrode interfaces of CaCu3Ti4O12 thin film capacitors. Appl. Phys. Lett. 91, 202903 (2007).
Y.L. Zhao, G.W. Pan, Q.B. Ren, Y.G. Cao, L.X. Feng, and Z.K. Jiao: High-dielectric constant in CaCu3Ti4O12 thin film prepared by pulsed laser deposition. Thin Solid Films 445, 7 (2003).
G. Deng, N. Xanthopoulos, and P. Muralt: Chemical nature of colossal dielectric constant of CaCu3Ti4O12 thin film by pulsed laser deposition. Appl. Phys. Lett. 92, 172909 (2008).
M. Mitsugi, S. Asanuma, Y. Uesu, M. Fukunaga, W. Kobayashi, and I. Terasaki: Origin of colossal dielectric response of CaCu3Ti4O12 studied by using CaTiO3 /CaCu3Ti4O12/CaTiO3 multilayer thin films. Appl. Phys. Lett. 90, 242904 (2007).
L. Fang, M. Shen, J. Yang, and Z. Li: Reduced dielectric loss and leakage current in CaCu3Ti4O12/SiO2/CaCu3Ti4O12 multilayered films. Solid State Commun. 137, 381 (2006).
S.Y. Lee, Y.H. Kim, K.J. Choi, S.M. Jung, and S.I. Yoo: Effect of copper-oxide segregation on the dielectric properties of CaCu3Ti4O12 thin films fabricated by pulsed laser deposition. Thin Solid Films 518, 5711 (2010).
G. Deng, Z. He, and P. Muralt: Physical aspects of colossal dielectric-constant material CaCu3Ti4O12 thin films. J. Appl. Phys. 105, 084106 (2009).
L. Fang, M. Shen, and Z. Li: Effect of double-sided CaTiO3 buffer layers on the electrical properties of CaCu3Ti4O12 films on Pt/Ti/SiO2 /Si substrates. J. Appl. Phys. 100, 104101 (2006).
L. Fang and M. Shen: Effect of laser fluence on the microstructure and dielectric properties of pulsed laser-deposited CaCu3Ti4O12 thin films. J. Cryst. Growth 310, 3470 (2008).
D. Maurya, D.P. Singh, D.C. Agrawal, and Y.N. Mohapatra: Preparation of high-dielectric constant thin films of CaCu3Ti4O12 by sol–gel. Bull. Mater. Sci. 31, 55 (2008).
R. Jimenez, M.L. Calzada, I. Bretos, J.C. Goes, and A.S.B Sombra: Dielectric properties of sol–gel derived CaCu3Ti4O12 thin films onto Pt/TiO2/Si(1 0 0) substrates. J. Eur. Ceram. Soc. 27, 3829 (2007).
Y.W. Li, Z.G. Hu, J.L. Sun, X.J. Meng, and J.H. Chu: Preparation and properties of CaCu3Ti4O12 thin film grown on LaNiO3-coated silicon by sol–gel process. J. Cryst. Growth 310, 378 (2008).
L.C. Chang, D.Y. Lee, C.C. Ho, and B.S. Chiou: Thickness-dependent microstructures and electrical properties of CaCu3Ti4O12 films derived from sol–gel process. Thin Solid Films 516, 454 (2007).
D.P. Singh, Y.N. Mohapatra, and D.C. Agrawal: Dielectric and leakage current properties of sol–gel derived calcium copper titanate (CCTO) thin films and CCTO/ZrO2 multilayers. Mater. Sci. Eng., B 157, 58 (2009).
E. Joanni, R. Savu, P.R. Bruno, E. Longo, and J.A. Varela: P-type semiconducting gas sensing behavior of nanoporous rf sputtered CaCu3Ti4O12 thin films. Appl. Phys. Lett. 92, 132110 (2008).
S.Y. Lin, Y.C. Chen, C.M. Wang, K.S. Kao, and C.Y. Chan: Effect of rapid thermal annealing on sputtered CaCu3Ti4O12 thin films. J. Electron. Mater. 38, 453 (2009).
B.S. Prakash, K.B.R Varma, D. Michau, and M. Maglione: Deposition and dielectric properties of CaCu3Ti4O12 thin films deposited on Pt/Ti/SiO2/Si substrates using radio frequency magnetron sputtering. Thin Solid Films 516, 2874 (2008).
R.L. Nigro, R.G. Toro, G. Malandrino, I.L. Fragala, P. Fiorenza, and V. Raineri: Chemical stability of CaCu3Ti4O12 thin films grown by MOCVD on different substrates. Thin Solid Films 515, 6470 (2007).
R.L. Nigro, R.G. Toro, G. Malandrino, I.L. Fragala, P. Fiorenza, and V. Raineri: Effects of high temperature annealing on MOCVD grown CaCu3Ti4O12 films on LaAlO3 substrates. Surf. Coat. Technol. 201, 9243 (2007).
S.Y. Lee, D.K. Yoo, and S.I. Yoo: Microstructures and dielectric properties of Cu deficient and excess CaCu3Ti4O12 polycrystalline ceramics. Electron. Mater. Lett. 3, 23 (2007).
W.W. Jung, S.K. Choi, S.Y. Kweon, and S.J. Yeom: Platinum (100) hillock growth in Pt/Ti electrode stack for SrBi2Ta2O9 ferroelectric random access memory. J. Electroceram. 13, 55 (2004).
H. Chen, C. Yang, C. Fu, J. Zhang, J. Liao, and L. Hu: Effects of interface on the dielectric properties of Ba0.6Sr0.4TiO3 thin film capacitors. Appl. Surf. Sci. 254, 3175 (2008).
J. Wang, T. Zhang, B. Zhang, J. Jiang, R. Pan, and Z. Ma: Interfacial characteristic of (Ba, Sr)TiO3 thin films deposited on different bottom electrodes. J. Mater. Sci.- Mater. Electron. 20, 1208 (2009).
J.X. Liao, C.R. Yang, J.H. Zhang, C.L. Fu, H.W. Chen, and W.J. Leng: The interfacial structures of (Ba, Sr)TiO3 films deposited by radio frequency magnetron sputtering. Appl. Surf. Sci. 252, 7407 (2006).
C. Zhao, Q. Zhu, D. Wu, and A. Li: Composition-dependent electrical characteristics and interface microstructures of solution-derived Nd-substituted Bi4Ti3O12 thin films on Pt electrodes. J. Phys. D: Appl. Phys. 42, 185412 (2009).
M. Abazari, E.K. Akdogan, and A. Safari: Dielectric and ferroelectric properties of strain-relieved epitaxial lead-free KNN-LT-LS ferroelectric thin films on SrTiO3 substrates. J. Appl. Phys. 103, 104106 (2008).
P. Gonon and F.E.I Kamel: Dielectric response of Cu/amorphous BaTiO3 /Cu capacitors. J. Appl. Phys. 101, 073901 (2007).
T.B. Massalski, H. Okamoto, P.R. Subramanian, and L. Kacprzak: Binary Alloy Phase Diagrams, 2nd, ed. (Orlando, FL: Alloy phase diagram international commission, 1986), Vol. 2 p.1461.
A. Vorobiev, P. Rundqvist, and K. Khamchane: Microwave loss mechanisms in Ba0.25Sr0.75TiO3 thin film varactors. J. Appl. Phys. 96, 4642 (2004).
R.L. Nigro, G. Malandrino, R.G. Toro, M. Losurdo, G. Bruno, and I.L. Fragala: Recent advances in characterization of CaCu3Ti4O12 thin films by spectroscopic ellipsometric metrology. J. Am. Chem. Soc. 127, 13772 (2005).
L. Fang, M. Shen, J. Yang, and Z. Li: The effect of SiO2 barrier layer on the dielectric properties of CaCu3Ti4O12 films. J. Phys. D: Appl. Phys. 38, 4236 (2005).
Y.W. Li, Y.D. Shen, Z.G. Hu, F.Y. Yue, and J.H. Chu: Effect of thickness on the dielectric property and nonlinear current-voltage behavior of CaCu3Ti4O12 thin films. Phys. Lett. A 373, 2389 (2009).
B. Vodungbo, Y. Zheng, M. Marangolo, D. Demaille, and J. Varalda: Planar assembly of monodisperse metallic cobalt nanoparticles embedded in TiO2− δ matrix. J. Phys. Condens. Matter 19, 116205 (2007).
C. Mitterbauer, G. Kothleitner, and F. Hofer: Comparative electron energy-loss near-edge fine structure investigations of titanium oxides. Microsc. Microanal. 9, 834 (2003).
Acknowledgments
This work was supported by the Korea Science and Engineering Foundation grant funded by the Korea government (MEST: Ministry of Education, Science and Technology) (No. 2010-0027688).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lee, SY., Choi, SM., Kim, MY. et al. Microstructures and electrical properties of CaCu3Ti4O12 thin films on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition. Journal of Materials Research 26, 2543–2551 (2011). https://doi.org/10.1557/jmr.2011.226
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/jmr.2011.226