Microstructure and Properties of P（VDF-TrFE） ferroelectric capacitor Using Ni-Al as the bottom electrode

Pt/P（VDF-TrFE）/Ni-Al heterostructure capacitors have been fabricated first on SiO₂/Si（001） substrate,in which P（VDF-TrFE） copolymer ferroelectric film was prepared by sol-gel method and Ni-Al and Pt films were prepared by magnetron sputtering.X-ray analysis indicated that Ni-Al film is amorphous,while P（VDF-TrFE） film is crystallined.It is found that Pt/P（VDF-TrFE）/Ni-Al capacitor possesses well saturated loops,the remnant polarization and coercive voltage are7.6 μC/cm² and 45.7 V,respectigatively,at applied voltage of 90 V and 20 Hz.The leakage current density of the capacitor,measured at 40 V,is ~5.37×10^-6A/cm².Further analyses indicated that the Pt/P（VDF-TrFE）/Ni-Al ferroelectric capacitors satisfies the ohmic conduction behavior.Moreover,No obvious fatigue can be found the capacitors up to 109 swithching cycles.