Seeding effect of SrBi_(2)Ta_(2x)O_(9) thin buffer layer on crystallization and electric properties of SrBi_(2)Ta_(2)O_(9) thin films

摘要

The seeding effects of the pre-crystallized (RTP 750 deg C 30s) thin buffer layer, SrBi_(2)Ta_(2x)O_(9) (SBT, x(velence)0.9, 1.0, and 1.1), regarding the structure, the morphology and the ferroelectric properties of the SrBi_(2)Ta_(2)O_(9) ferroelectric thin films on top of buffer layer, have been investigated. X-ray diffraction patterns revealed that the crystallinity of SrBi_(2)Ta_(2)O_(9) thin films were significant influenced by the buffer layers with various Ta contents. By adding a Ta deficient buffer layer, the preferred polar a-axis orientation and the uniformity of grain size within the SBT thin films were promoted. Meanwhile, the optimized ferroelectric properties were achieved from the SrBi_(2)Ta_(1.8)O_(9) buffered SrBi_(2)Ta_(2)O_(9) thin film, with maximum 2Pr values about 19.7 (mu)C/cm~(2), which was almost 93percent greater than that of specimen with the stoichiometric buffered one.