以Ni-Al为底电极的P(VDF-TrFE)铁电电容器的结构与性能

应用磁控溅射法制备Ni-Al和Pt薄膜,溶胶-凝胶法制备P(VDF-TrFE)铁电共聚物薄膜,在SiO2/Si(001)衬底上首次构架了Pt/P(VDF-TrFE)/Ni-Al异质结电容器。X射线衍射(XRD)结果表明:Ni-Al薄膜为非晶结构,P(VDF-TrFE)薄膜具有较好的结晶质量。研究发现,在20 Hz测试频率下,Pt/P(VDF-TrFE)/Ni-Al电容器具有饱和的电滞回线,在90 V驱动电压下,剩余极化强度与矫顽场分别为7.6μC/cm2和45.7 V。在外加电压为40 V时,薄膜的漏电流密度约为5.37×10-6 A/cm2。漏电机制研究表明,Pt/P(VDF-TrFE)/Ni-Al电容器满足欧姆导电机制。铁电电容器经过109极化反转后没有发现明显的疲劳现象。

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.