Thermally induced voltage offsets in Pb(Zr,Ti)O-3 thin films

Voltage offset in the polarization-voltage characteristics of Pb(Zr,Ti)O-3 (PZT) capacitors was evaluated by a thermal stress process. A thermally ind uced voltage shift occurs when heating the sample under either remanence or a saturating bias. It was found that the voltage shifts can, to a large ex tent, be attributed to the role of charged defects and the defect-dipole al ignment throughout the films. PZT film with a high Zr/Ti ratio, i.e., rhomb ohedral compositions exhibited the best imprint resistance. When these film s were doped wit up to 6% La, the imprint resistance was further improved. It was also found that B-site donors were more effective in minimizing the voltage shift than A-site donors. However, dopants with the same charge val ue as Pb, for example, Ca and Sr, did not affect the thermally induced volt age shifts of the films since they could not reduce the charged defects in the films. (C) 2000 American Institute of Physics. [S0003-6951(00)04145-0].