%0 Journal Article %K thin films %K defects %K Polarization %K Ferroelectric materials %K Doping (additives) %K Ferroelectric devices %K Lead compounds %K Ferroelectric capacitors %K Capacitors %K Composition effects %K Compositional dependent oxygen vacancy density %K Ferroelectric memory devices %K Imprint %K Oxygen vacancy related defect dipole %K Polarization voltage characteristics %K Stress induced voltage shift %K Thermal induced voltage shift %K Voltage offset %A W.L Warren %A B.A Tuttle %A D Dimos %A G.E Pike %A H.N Al-Shareef %A Ramamoorthy Ramesh %A J .T Jr %B Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers %D 1996 %G eng %P 1521-1524 %T Imprint in ferroelectric capacitors %V 35 %X We show that voltage offsets in the polarization-voltage characteristics of Pb(Zr, Ti)O3 capacitors can lead to imprint in ferroelectric memory devices. The thermal-induced voltage shifts (internal bias field) are in part attributed to the role of oxygen vacancy-related defect dipoles throughout the film. In support of this, it is found that donor doping at the Ti(Zr) sites reduces the thermally-induced voltage shifts. The stress-induced voltage shifts are found to be dependent on the Zr/Ti cation ratio. This compositional dependence is explained by considering the role of deep bulk Ti3+ centers and/or a compositional dependent oxygen vacancy density.