Improvements in electrical properties of hydrogen-treated SrBi2Ta2O9 capacitors with chemical vapor deposited Pt top electrode

The ferroelectric property and leakage current of metalorganic chemical vap or deposition (MOCVD)-Pt/SrBi2Ta2O9 (SBT)/Pt and dc-sputtered Pt/SBT/Pt cap acitors are evaluated with the microstructures of Pt top electrodes before and after hydrogen forming gas anneal. The SBT films with MOCVD-Pt top elec trodes of large grain size and dense structure show a surprising decrease o f leakage current density and still exhibit ferroelectric properties after hydrogen forming. On the other hand, SBT films with dc-sputtered Pt top ele ctrodes of small grain size show an increase of leakage current density and then polarization switching properties cannot be measured due to fairly hi gh leakage current. The microstructures of Pt top electrodes play an import ant role in improving the ferroelectric and leakage current characteristics after forming gas anneal. MOCVD-Pt top electrodes can prevent the complete loss of ferroelectricity and improve the leakage current properties during forming gas treatment. (C) 2001 American Institute of Physics.