The changes of structure and chemical composition of SrBi2Ta2O9 (SBT) thin films, which were annealed at 500 degrees C in N-2 and forming gas (5%H-2 + 95%N-2), were investigated. Cross sectional morphology of SBT film was observed by scanning electron microscopy. The chemical composition and state were determined by using X-ray photoelectron microscopy and Auger electron spectrometer, respectively. N-2 played a different role in annealing processes from forming gas. In the case of forming gas annealing, Bi element was reduced and appeared on the surface of SBT film or inside Si substrate. In the case of N-2 annealing, only slight inter-diffusion occurs at SBT/Pt interface and small amounts of Bi are seen at Pt electrode layer. It could be attributed to the high annealing temperature. Compared with films annealed in forming gas, SBT films annealed in N-2 exhibit better microstructure quality.

Keywords: SBT thin films; Interface; XPS; Annealing atmosphere; Structural