Charaterization of (Bi,La)Ti3O12 Ferroelectric Thin Films on Pt/Ti/SiO2/Si Substrates by sol-gel Method

Metal-Ferroelectric-Metal(MFM) capacitors were prepared using $Bi_{3.3}$ $La_{0.7}$ $Ti_3$$O_{12}$ (BLT) ferroelectric thin films which were spin coated on $Pt/Ti/SiO_2$/Si substrates by the Sol-Gel method. BLT thin films annealed at above $650^{\circ}C$ showed polycrystalline structures with typical c-axis preferred orientation. The grain size and surface roughness were increased as the annealing temperature increased from $650^{\circ}C$ to $700^{\circ}C$. In addition, the full width at half maximum (FWHM) values were decreased with increasing annealing temperatures, indicating the improvement of crystallinity. The remanent polarization (2Pr= $Pr^{+}$ $+Pr^{-) }$ and leakage current of the BLT film annealed at $650^{\circ}C$ were about 29.3 $\mu$C/cm$^2$ and $2.3$\times$10^{-8}$$ A/cm^2$ at 3V. There were no distinct changes in the retention charges after $10^{10}$ polarization switching cycles, showing good fatigue property of the annealed BLT films.

졸-겔법으로 Pt/Ti/SiO2/Si 기판위에 제작된 (Bi,La)Ti3O12 강유전체 박막의 특성 연구