C-axis oriented lead germanate film

Year	Description
2001	Invention patented by Tingkai Li, Fengyan Zhang, Yoshi Ono, and Sheng Teng Hsu on August 28th, 2001. Abstract: A ferroelectric Pb.sub.5 Ge.sub.3 O.sub.11 (PGO) thin film is provided with a metal organic vapor deposition (MOCVD) process and RTP (Rapid Thermal Process) annealing techniques. The PGO film is substantially crystallization with c-axis orientation at temperature between 450 and 650.degree. C. The PGO film has an average grain size of about 0.5 microns, with a deviation in grain size uniformity of less than 10%. Good ferroelectric properties are obtained for a 150 nm thick film with Ir electrodes. The films also show fatigue-free characteristics: no fatigue was observed up to 1.times.10.sup.9 switching cycles. The leakage currents increase with increasing applied voltage, and are about 3.6.times.10.sup.-7 A/cm.sub.2 at 100 kV/cm. The dielectric constant shows a behavior similar to most ferroelectric materials, with a maximum dielectric constant of about 45. These high quality MOCVD Pb.sub.5 Ge.sub.3 O.sub.11 films can be used for high density single transistor ferroelectric memory applications because of the homogeneity of the PGO film grain size.
Source: selected by the editor from original sources.

Invention: C-axis oriented lead germanate film