PREPARATION AND CHARACTERIZATION OF HIGHLY C-AXIS-ORIENTED BI4TI3O12 THIN-FILMS

Highly c-axis-oriented bismuth titanate (Bi4Ti3O12) thin films were pr epared on (100)-oriented silicon wafers by rf planar magnetron sputter ing using a target of Bi2TiO5 ceramic at a low substrate temperature o f 600 degrees C. The films with a c-axis orientation up to 99% were ob tained under high deposition rate approximately 1.1 mu m h(-1). Dielec tric constant of these films were dependence of film thickness. This b ehavior was explained assuming a low-dielectric-constant interface lay er. Using this assumption, the dielectric constant of Bi4Ti3O12 film w as estimated to be approximately 140. This value is similar to that al ong the c-axis in a bulk form. A D-E hysteresis characteristic has bee n observed at room temperature. The remanent polarization and the coer cive field are 0.8 mu C cm(-2) and 20 kV cm(-1), respectively. From an alysis of refractive index, interface layer was confirmed an oxidized silicon, which was formed before and/or during film deposition.