Preparation and basic properties of SrBi2Ta2O9 films

Ferroelectric SrBi2Ta2O9 thin films have been prepared on Pt and SiO2/n-Si(100) by laser ablation using an ArF excimer laser below 560 degrees C. Crystallographic properties of the films are characterized as a function of substrate temperature and ambient pressure. Preferentially (105)-oriented SrBi2Ta2O9 thin films are obtained on SiO2/Si and Pt sheets. D-E hysteresis loops are observed in SrBi2Ta2O9 thin films deposited on Pt sheets. The remnant polarization is 2.5 mu C/cm(2) and the coercive force is 34kV/cm. The films deposited on SiO2/Si consist of grains about 100 nm in diameter. Depth profiles from X-ray photoelectron spectra reveal homogeneous compositions, and the elements of the film diffuse little at the interface between the SrBi2Ta2O9 thin film and SiO2. The energy distributions of the density of interface states are below 10(12) cm(-2)eV(-1) in SiO2/Si at 550 degrees C and below 3 x 10(11) cm(-2)eV(-1) at 400 degrees C. A good capacitance-voltage hysteresis curve is obtained in the metal-ferroelectric-oxide-semiconductor structure using the SrBi2Ta2O9 film on SiO2/Si at T-s of 550 degrees C.