Influence of Pt heterostructure bottom electrodes on SrBi2Ta2O9 thin film properties

Abstract

The properties of ${\mathrm{SrBi}}_{\mathrm{2}}{\mathrm{Ta}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{9}}$ (SBT) films, such as remanent polarization and leakage current density, are closely related to the film/electrode interface and surface roughness of the underlying electrode. SBT films grown on stable ${\mathrm{Pt/TiO}}_{\mathrm{2}}{\mathrm{/SiO}}_{\mathrm{2}}\mathrm{/Si}$ and ${\mathrm{Pt/ZrO}}_{\mathrm{2}}{\mathrm{/SiO}}_{\mathrm{2}}\mathrm{/Si}$ substrates exhibit high remanent polarization, low leakage current density, and low voltage saturation as compared to SBT films synthesized on ${\mathrm{Pt/Ti/SiO}}_{\mathrm{2}}\mathrm{/Si}.$ It is shown that severe diffusion of Ti from the Ti interlayer onto the surface of the Pt bottom electrode and the increased surface roughness of this electrode stack play key roles in degradation of SBT properties.