Structural and ferroelectric properties of the c-axis oriented SrBi2Ta2O9 thin films deposited by the radio-frequency magnetron sputtering

Abstract

Radio-frequency magnetron sputtering was used to deposit SrBi2Ta2O9 ferroelectric thin films on Pt(111)/Ti/SiO2/Si(001) substrates. Thin films were deposited at room temperature with argon pressures of 0.5-100 mTorr and with sputtering power of 2.5 W/cm(2). The crystal orientations of thin films were strongly affected by the argon pressures, the c axis oriented SrBi2Ta2O9 thin film was obtained with argon pressure of 30 mTorr. The crystal structures of the c-axis oriented SrBi2Ta2O9 thin film were investigated by x-ray diffraction methods: theta-2 theta scan, rocking curve, and phi scans. The well aligned microstructure was observed with the average grain size of about 2000 Angstrom in an atomic force microscopic image. Ferroelectric properties were observed for the c-axis oriented thin film: P-r*-P-r(boolean AND) and E(c) were 9.7 mu C/cm(2) and 50 kV/cm, respectively, with excitation voltage of 3 V. (C) 1996 American Institute of Physics.