The time domain and electric field dependence of the polarization switching kinetics of poly(vinylidene fluoride-trifluoroethylene) copolymer based thin film metal-ferroelectric-metal capacitors have been characterized. At room temperature, the time required for complete switching polarization decreases from >1 s to <50 μs as the voltage is increased from 6 to 12 V, while low nonswitching polarization is maintained. In the time domain, the ferroelectric switching polarization reversal behavior for devices biased above the coercive field follows the nucleation-limited-switching model. The exponential relationship between switching time and applied electric field indicates nucleation dominated switching kinetics. Switching behavior as a function of temperature was also characterized from -60 to 100 °C in the voltage range of 6-12 V. Higher temperatures induce larger dc conductance leakage at low frequencies and increases nonswitching polarization for all the voltages studied. It is demonstrated that for certain frequencies, by controlling the switching voltage, our optimized ferroelectric thin film capacitor shows stable switching polarization in a temperature range compatible with flexible electronics applications.
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The authors would like to thank Dr. Scott R. Summerfelt of Texas Instruments for helpful discussions on FRAM characterization, Kamil Mielczarek from the Department of Physics at UT Dallas for the Au thermal evaporation of the top contact for the MFM capacitors and the Army Research Laboratory (ARL) for partial financial support of this project. We would also like to thank Dr. Eric Forsythe of ARL for helpful discussions regarding nonvolatile memory integration.