Microstructure and ferroelectric properties of bi-excess Bi₄Ti₃O₁₂ thin films grown on Si and Pt/Ti/SiO₂/Si substrates

Abstract

Bismuth layer-structured ferroelectric Bi₄Ti₃O₁₂ thin films have been deposited on n-type Si(111) and Pt(111)/Ti/SiO₂/Si substrates using rf-magnetron sputtering process. The effects of substrates and annealing treatments on microstructure and ferroelectric properties were investigated. Scanning electron microscopy and X-ray diffraction patterns exhibited that the as-deposited thin films were noncystalline and transformed to crystalline Bi₄Ti₃O₁₂ phase with a second phase of Bi₁₂TiO₂₀ after annealed at 700 °C. Ferroelectric properties showed that as-deposited thin film in metal-ferroelectric-semiconductor capacitor form and annealed thin film in metal-ferroelectric-metal form exhibited typical ferroelectric behaviors, wherein the values of remnant polarization were around 0.8 µC/cm² and 4.8 µC/cm², respectively.

Keywords:

• Bismuth titanate
• thin films
• sputtering
• ferroelectric properties

Disclosure statement

The authors declare no financial/commercial conflicts of interest.