Abstract: Ni-Al films with different thicknesses used as the bottom electrode layers are prepared on Si(100) at room temperature by magnetron sputtering method, and P(VDF-TrFE) copolymer film is prepared by direct dripping method, which is followed by an annealing process to further obtain Al/ P(VDF-TrFE)/Ni-Al/Si ferroelectric capacitor heterostructures through a shadow mask. Various techniques, such as X-ray diffraction (XRD), ferroelectric tester (Precision LC unit) have been employed to characterize the microstructure and ferroelectric properties of the ferroelectric capacitors. It is found that thickness of Ni-Al film have a large effect on leakage current of P(VDF-TrFE) copolymer film. When the thickness of Ni-Al film is 36 nm, leakage current density of P(VDF-TrFE) copolymer film is 2.09×10~(-5) A/cm~2. Leakage current mechanism of the Al/ P(VDF-TrFE)/Ni-Al/Si ferroelectric capacitor is further investigated, it is found that Al/ P(VDF-TrFE)/Ni-Al/Si corresponds to Ohmic conduction behavior at low electric field and Schottky emission at higher electric field.

Key words: P(VDF-TrFE), leakage current, Ni-Al