Articles you may be interested inPolarization behavior of poly(vinylidene fluoride-trifluoroethylene) copolymer ferroelectric thin film capacitors for nonvolatile memory application in flexible electronics J. Appl. Phys. 108, 094102 (2010); 10.1063/1.3500428 Transparent photostable ZnO nonvolatile memory transistor with ferroelectric polymer and sputter-deposited oxide gate Electrical investigations on metal/ferroelectric/insulator/semiconductor structures using poly[vinylidene fluoride trifluoroethylene] as ferroelectric layer for organic nonvolatile memory applications Comparative electrical bistable characteristics of ferroelectric poly(vinylidene fluoride-trifluoroethylene) copolymer based nonvolatile memory device architectures Appl. Phys. Lett. 93, 182902 (2008); 10.1063/1.3013835Low-voltage operation of ferroelectric poly(vinylidene fluoride-trifluoroethylene) copolymer capacitors and metalferroelectric-insulator-semiconductor diodes

Metal-ferroelectric-insulator-Si (MFIS) diodes using poly(methyl methacrylate) (PMMA)-blended poly(vinylidene fluoride)-trifluoroethylene [P(VDF-TrFE)] as a gate ferroelectric film were fabricated and their electrical characteristics were investigated. A wide memory window of 1.2 V was observed in a Au/3 wt % PMMA-blended P(VDF-TrFE) (46 nm)/HfTaO(6 nm)/Si MFIS diode for the voltage sweep between −3 and +3 V. Excellent data retention characteristics were also observed in these MFIS diodes. After a small programing voltage of 3 V is applied, the high and low capacitances remained very stable for the retention period over 4 h.

Oxygen plasma etching characteristics of ferroelectric poly͑vinylidene fluoride-trifluoroethylene͒ copolymer films are investigated. It was found in MFM ͑M: metal; F: ferroelectric͒ capacitors that plasma damage effects to the ferroelectric properties were insignificant when Au metal masks were used. On the contrary, C-V ͑capacitance versus voltage͒ characteristics were significantly degraded in plasma-etched MFIS ͑I: insulator; S: semiconductor͒ diodes. The origin of this phenomenon is speculated to be degradation of the SiO 2 / Si interface by energetic oxygen ions and then mixing of Kr gas to the oxygen plasma is attempted to decrease the plasma damage.Organic ferroelectrics such as poly͑vinylidene fluoridetrifluoroethylene͒ ͓p͑VDF-TrFE͔͒ have widely been investigated structurally 1,2 and electrically. 3-7 It has been reported that the polarization reversal time in a 50-nm-thick p͑VDF-TrFE͒ film is as fast as 500 ns at an electric field of 2 MV/ cm, 5 and that the coercive voltage ͑V c ͒ in a 60-nm-thick p͑VDF-TrFE͒ film is as low as 2 V, keeping the remanent polarization ͑P r ͒ larger than 10 C / cm 2 . 8 Fabrication of organic nonvoltage memory transistor has also been reported. 9 These organic ferroelectrics might also be used in fabrication of ferroelectric-gate Si transistors because of the following properties which are in contrast with those of oxide ferroelectric films such as Pb͑Zr, Ti͒O 3 ; ͑1͒ the crystallization temperature is so low ͑typically 140°C͒ that no interaction between the film and substrate nor interdiffusion of the constituent elements is expected, even if the film is crystallized on Si directly, and ͑2͒ even if an interfacial layer is inserted between the ferroelectric film and Si substrate unintentionally or intentionally since the dielectric constants of organic ferroelectrics are low ͑typically 10-15͒, the external voltage is effectively applied to the ferroelectric film, and thus low voltage operation of the memory device can be expected. To fabricate ferroelectric-gate transistors in small size, however, it is important to investigate degradation of the ferroelectric films during wet and dry etching processes. Thus, we investigate in this letter the ferroelectric and leakage current characteristics of MFM ͑M: metal; F: ferroelectric͒ capacitors and MFIS ͑I: insulator; S: semiconductor͒ diodes, before and after the films are etched by oxygen plasma.p͑VDF-TrFE͒ films with a composition ratio of 72: 28 wt % were prepared by a spin-coating method on Pt/ TiN / SiO 2 / Si structures at 3000 rpm for 15 s. The deposited layer was dried at 120°C for 5 min in air. These processes were repeated until the film thickness became approximately 100 nm. Finally, the dried films were annealed at 140°C in air. Then, Au top electrodes of 200 m in diameter were formed on the annealed films by thermal evaporation, and P-E ͑polarization versus electric field͒ and J-V ͑current density versus voltage͒ characteristics of the MFM capacitors were measured. Next, the p͑VDF-TrFE͒ films were etched in oxygen pl...

Ferroelectric poly(vinylidene fluoride–trifluoroethylene) [P(VDF–TrFE)] and poly(methyl metacrylate) (PMMA)-blended P(VDF–TrFE) thin films are deposited by spin coating on Pt/TiO2/SiO2/Si, and their fatigue endurance is investigated by forming metal–ferroelectrics–metla (MFM) capacitors. It has been found that fatigue endurance is significantly improved by blending PMMA into P(VDF–TrFE). Under the tested conditions, the best endurance for alternating voltage pulses is obtained in the 4 wt % PMMA blended P(VDF–TrFE) film.

We have investigated a solution of tetrabutylammonium iodide (TBAI) in the polar solvent formamide (FA) using angle-resolved photoelectron spectroscopy at the Berlin Electron Storage Ring for Synchrotron Radiation (BESSY). The concentration was set to 0.5 molality. We have evaluated the signals from C Is pertaining to TBAL and FA sepmtely. varying the photon energy between 310 and 540 eV as well as the bemission angle with respect to the surface normal. The combination of these data with earlier results from AMPS obtalned by Siegbahn and co-workers allowed us to establish a concentration-depth profile of the surface-active salt TBAI. For this purpose we have employed a new theoretical formulation and developed a new elaborate fitting program based on a genetic algorithm. The concentration of the salt could be followed down to a depth of about 45 8, below the surface. Cross sections for the inelastic energy loss of electrons in the liquid could be established as a function of electron energy. Comparison with conventional surface tension measurements allowed us to derive absolute values for the cross sections.