THE STABILITY INVESTIGATION OF FERROELECTRIC SrBi2Ta2O9 THIN FILMS ANNEALED IN FORMING GAS

The hysteresis loop changes of ferroelecric SrBi2 Ta2 O9 (SBT) thin films (330nm) vsthe temperature of forming gas (5%o hydrogen+95%o nitrogen) annealing were measuredwhen the annealing time was 1min and 10min. The selected annealing temperaturewas at 100℃, 200℃, 250℃, 300℃, 350℃, 400℃ and 4S0℃, respectively. Our resultsshowed that the ferroelectric properties were easily destroyed and the leakage currentchanged abruptly when the SBT thin films were in their ferroelectric phase (＜270℃).The space charges at the grain boundary may take an important role in absorptionpolarity molecular hydrogen when the SBT thin films were in the ferroelectric phase.The oxygen recovery experiments were also performed and investigated in this work.