Physical properties of spin-on solution deposited Bi₄Ti₃O₁₂ thin films on Si substrates

Abstract

Using spin-on solution and metalorganic decomposition, thin Bi₄Ti₃O1₂ films were deposited directly onto silicon substrates. Crystallization was performed by thermal annealing at temperatures in the 550[ddot]G-700°C range. The film structure and morphology were investigated by X-ray diffraction, scanning electron mycroscopy and atomic force microscopy. The dispersion of the refractive index for Bi4Ti3O12 thin films was measured using spectroscopic ellipsometry. The MFS structures were electrically characterized by C-V and I-V measurements. From C-V measurements, which confirm hysteretic behavior, the memory window has a maximum value of 3.35 V for an annealing at 600°C, and the relative permittivity has a maximum value of 90 after annealing at 575°C. The I-V characteristic is asymmetric, with a hysteresis and a non-zero current at zero applied bias. Several possible explanations are proposed to explain this transient current.