Recent advances in ferroelectric polymer thin films for memory applications

An overview of ferroelectric VDF/TrFE copolymer thin films is presented based on our recent work on their phase transition behavior and polarization switching dynamics. These properties originate in the hierarchical structures consisting of monomer dipoles, all-trans conformation, parallel chain packing and crystalline orientation in thin films. Successive loss of intermolecular and intramolecular orders yields multiple phase transitions from a ferroelectric phase to a molten phase via anti-ferroelectric and paraelectric phases. Polarization switching dynamics are shown to depend on a variety of factors not only applied field strength but also electrode, substrate, thickness and wave form of applied field. These results are discussed in relation to their hierarchical structures as well as nonvolatile memory applications.