Impacts of postannealing ambient atmospheres on Pt-SrBi_2.2Ta_2O_9/Pt capacitors

摘要

SrBi_2.2Ta_2O_9(SBT)films were prepared on Pt/TiO_2/SiO_2/Si substrates at 750 deg. C in oxygen by the mebalorganic decomposition method. SBT film capacitors were postannealed in Ar(N_2)at 350-750 deg. C and then rennealed in O_2 at 750 deg. C. Effects of annealing atmosphere on the structure, morphology, and ferroelectric properties have been investigated systematically. The composition analyses indicate Ar-or N_2-annealing at 750 deg. C leads to Bi evaporation and oxygen loss. Above 550 deg. C 100/100 Ar or N_2 postannealing, the remnant polarization decreases and the coercive field Increases significantly.