Fabrication of multilayer ferroelectric films

• Published in: Integrated ferroelectrics Vol. 25; no. 1-4; pp. 275 - 286
• Main Authors: Neumayer, Deborah A., Duncombe, Peter R., Laibowitz, Robert B., Shaw, Thomas, Berndt, Lisa, Black, C. T., Grill, Alfred
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.09.1999
• Subjects: bismuth titanate; chemical solution deposition; ferroelectric; strontium bismuth tantalate
• ISSN: 1058-4587; 1607-8489
• DOI: 10.1080/10584589908210178

Multilayers of strontium bismuth tantalate (Sr 0.9 Bi 2.2 Ta 2 O 9 , SBT) with bismuth titanate (Bi 4 Ti 3 O 12 , BT), and SBT and strontium bismuth niobate (Sr 0.9 Bi 2.2 Nb 2 O 9 , SBN) with BT were prepared by chemical solution deposition (CSD). The CSD solutions were a mixture of strontium, tantalum, niobium and titanium butoxyethoxides and bismuth ethylhexanoate dissolved in butoxyethanol. SBT films were fabricated and annealed at 800°C for 60 min. Generally, all capacitors of the SBT films tested had low resistance with as-deposited Pt top electrodes and no ferroelectricity could be measured. After a post electrode anneal at 800°C for 30 min, a percentage of capacitors could be tested for ferroelectricity, and a 2Pr of 15 μC/cm 2 at 3V was typically measured. Multilayer SBT, and SBT and SBN with BT were rapidly thermally annealed for a total (including post electrode anneal) of 20-40 min at 750°C. The multilayer SBT and SBN with BT, and SBT with BT films exhibited a wide range of 2Pr values ranging from 2-14 μC/cm 2 at 3V but had a larger percentage of measurable capacitors after post electrode anneal than the SBT only films. In addition, no fatigue was observed after 10 11 cycles in a SBT with BT multilayer structure.