The ferroelectric properties of c-axis oriented Pb5Ge3O11 thin films prepared by metalorganic chemical vapor deposition

C-axis oriented ferroelectric Pb5Ge3O11 thin films were prepared on Pt/Ir-coated Si wafers by metalorganic chemical vapor deposition (MOCVD) and rapid thermal process annealing techniques. The films were specular and crack free and showed complete crystallization with c-axis orientation for growth temperatures between 500 and 550 °C. Good ferroelectric properties were obtained for a 150-nm-thick film with Pt/Ir electrodes: the remanent polarization (2Pr) and coercive field (2Ec) values were about 3.8 μC/cm2 and 93 kV/cm, respectively. The films also showed excellent fatigue characteristics: no fatigue was observed up to 1×109 switching cycles. The leakage current increased with increasing applied voltage, and is about 3.6×10−7 A/cm2 at 100 kV/cm. The dielectric constant showed behavior similar to most ferroelectric materials in that the dielectric constant changed with applied voltages. The maximum dielectric constant is about 45. High-quality MOCVD Pb5Ge3O11 films can be used for single transistor ferroelectric memory devices.