Improved dielectric properties of CaCu3Ti4O12 films with a CaTiO3 interlayer on Pt/TiO2/SiO2/Si substrates prepared by pulsed laser deposition

• Published in: Electronic materials letters Vol. 11; no. 6; pp. 1003 - 1011
• Main Authors: Lee, Sung-Yun, Kim, Hui Eun, Jo, William, Kim, Young-Hwan, Yoo, Sang-Im
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.11.2015; 대한금속·재료학회
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed Matter Physics; Materials Science; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; 전자/정보통신공학; films; dielectric property; Ti; pulsed laser deposition; leakage current; Poole-Frenkel conduction model; CaCu; O
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-015-5211-x

We report the greatly improved dielectric properties of CaCu 3 Ti 4 O 12 (CCTO) films with a 60 nm-thick CaTiO 3 (CTO) interlayer on Pt/TiO 2 /SiO 2 /Si substrates. Both CCTO films and CTO interlayers were prepared by pulsed laser deposition (PLD). With increasing the thickness of CCTO from 200 nm to 1.3 μ m, the dielectric constants ( ε r ) at 10 kHz in both CCTO single-layered and CCTO/CTO double-layered films increased from ∼260 to ∼6000 and from ∼630 to ∼3700, respectively. Compared with CCTO single-layered films, CCTO/CTO double-layered films irrespective of CCTO film thickness exhibited a remarkable decrease in their dielectric losses ( tanδ ) (<0.1 at the frequency region of 1 - 100 kHz) and highly reduced leakage current density at room temperature. The reduced leakage currents in CCTO/CTO double-layered films are attributable to relatively higher trap ionization energies in the Poole-Frenkel conduction model.