FERROELECTRIC Sr2(Nb, Ta)2O7 THIN FILMS PREPARED BY CHEMICAL SOLUTION DEPOSITION

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 39, no. 9B, pp. 5521-5524. 2000 Vol. 39; no. 9B; pp. 5521 - 5524
• Main Authors: Kim, C Y, Koo, C Y, Woo, D C, Lee, H Y
• Format: Journal Article
• Language: English
• Published: 2000
• ISSN: 0021-4922
• DOI: 10.1143/jjap.39.5521

Ferroelectric Sr2(Nb, Ta)2O7 (SNTO) thin films were prepared by chemical solution deposition process, i.e. the modified sol-gel method. The stock solutions were spin-coated onto either Pt/Ti/SiO2/Si(100) or Pt/TiO2/SiO2/Si(100) substrate. After multiple coating/baking steps, dried thin film stacks were annealed for crystallization at 850-1000 C in O. XRD and SEM analyses revealed that the crystallization temperature by modified sol-gel process can be lowered to 850 C if Pt/TiO2/SiO2/Si(100) substrate was used, while temperature > 950 C is required for Pt/Ti/SiO2/Si(100) substrate. Leakage current and relative permittivity (er) values were measured in the range of about 10-9-10-7 A/cm2, and 30-45, resp., depending on the composition, heat-treatment and substrate type. Polarization hysteresis loops were not saturated regardless of composition and annealing temperature. Remanent polarization and coercive field values for typical SNTO(30/70) film were approx 1.9 mu C/cm2 and 17 kV/cm, resp., when plus/minus 5 V pulse was applied. 14 refs.