Fabrication and Characterization of Bismuth Lanthanum Titanate (Bi_3.25La_0.75Ti₃O₁₂) Thin Films for FeRAM Devices

Abstract

Thin films of Lanthanum doped Bismuth Titanate (Bi_3.25La_0.75Ti₃O₁₂) (BLT) have been prepared and characterized for their applications in ferroelectric random access memory (FeRAM) devices. The films have been characterized via X-ray diffraction (XRD), atomic force microscopy (AFM), capacitance-voltage (C-V), ferroelectric (P-E) and current-voltage (J-V) characteristics. The effect of thickness on these characteristics has also been investigated. Thickness variation shows significant effect on the morphology and ferroelectric properties of the films. The nature of the J-V characteristics was observed to be independent of the thickness of the films. Three distinct regions, i.e., ohmic, trap filled limited and Child's law were explicitly observed in J-V characteristics. The J-V behavior of BLT thin films was found to follow the Lampert's theory of space charge limited conduction in an insulator with traps.

Keywords:

• Ferroelectric thin films
• chemical solution deposition
• Bismuth layered structure
• Leakage current mechanism

Acknowledgments

One of the authors (Prikshit Gautam) is thankful to the Inter-University Accelerator Centre (IUAC), New Delhi, India for providing financial support through Project No.UFUP-37310/ 3797, Dr. Amitabh Basu (NPL, Delhi, India) for ellipsometry measurements.