PNNL

Abstract

A ferroelectric Pb5Ge3O11 thin film with a low dielectric constant is proposed for application in one transistor ferroelectric memories. A strong depolarization voltage on the ferroelectric capacitor wit MFSFET structures diminishes the remanent polarization significantly and therefore, the low dielectric constant becomes very important to widen the memory window. A memory window of 3V was estimated for the MFMOS memory structure with 2000A ferroelectric on Ir/Ti/SiO2/Si substrates, by using MOCVD system, was demonstrated. Germanium ethoxide, Ge(OC2H5)4, and lead bis-tetramethylheptadione, Pb(thd)2, were used as the MOVCD precursors. The film composition, phase formation, microstructure and ferroelectric properties are reported. The c-axis oreinted Pb5Ge3O11 thin films prepared by MOCVD and RTP post-annealing showed a square ferroelectric hysteresis loop with Pr of 2.83 uC/cm2 and Ec of 49 kV/cm. A low leakage current of 7.5 x 10 to the -7 A/cm2 at 100 kV/cm and low dielectric constant of 41 were also demonstrated.