Deposition method for lead germanate ferroelectric structure with multi-layered electrode

摘要

The ferroelectric structure including a Pt/Ir layered electrode used in conjunction with a lead germanate (Pb₅Ge₃O₁₁) thin film is provided. The electrode exhibits good adhesion to the substrate, and barrier properties resistant to oxygen and lead. Ferroelectric properties are improved, without detriment to the leakage current, by using a thin IrO₂ layer formed in situ, during the MOCVD lead germanate (Pb₅Ge₃O₁₁) thin film process. By using a Pt/Ir electrode, a relatively low MOCVD processing temperature is required to achieve c-axis oriented lead germanate (Pb₅Ge₃O₁₁) thin film. The temperature range of MOCVD c-axis oriented lead germanate (Pb₅Ge₃O₁₁) thin film on top of Pt/Ir is 400-500° C. Further, a relatively large nucleation density is obtained, as compared to using single-layer iridium electrode. Therefore, the lead germanate (Pb₅Ge₃O₁₁) thin film has a smooth surface, a homogeneous microstructure, and homogeneous ferroelectric properties. A method of forming the above-mentioned multi-layered electrode ferroelectric structure is also provided.