【摘要】 采用脉冲激光沉积 (PLD)工艺 ,制备了以Bi4Ti3O1 2 (BIT)为过渡阻挡层的Au PZT BIT p Si异质结 .研究了BIT铁电层对Pb(Zr0 .5 2 Ti0 .48)O3(PZT)薄膜晶相结构、铁电及介电性能的影响 ,对Au PZT BIT p Si异质结的导电机制进行了讨论 .氧气氛 5 30℃淀积的PZT为多晶铁电薄膜 ,与直接淀积在Si基片上相比 ,加入BIT铁电层后PZT铁电薄膜的 (110 )取向更加明显 ;在铁电层总厚度均为 40 0nm的情况下 ,PZT BIT双层铁电薄膜比PZT单层铁电薄膜具有更大的剩余极化和更低的矫顽场 ;观察到顺时针回滞的C V特性曲线 ,表明铁电极化控制了硅的表面势 ,薄膜呈现极化开关的特性 ;I V特性曲线表明异质结具有明显的单向导电性 ,并证实异质结在弱场下导电遵循欧姆定律 ,强场下以空间电荷限制电流 (SCLC)为主 ;异质结具有较好的疲劳特性 ,10 9次极化反转后其剩余极化仍达到初始值的90 % .更多还原

【Abstract】 The Au/PZT/BIT/p Si heterostructure was fabricated by pulsed laser deposition technique. The effect of introducing a BIT buffer layer between the PZT films and Si substrate on the crystallinity, the ferroelectric characteristics and the electrical characteristics of the ferroelectric film system, as well as the conductivity behavior of the Au/PZT/BIT/p Si heterostructure were investigated. The PZT films deposited on p\|Si with a BIT buffer layer were found to grow with a preferred orientation along(110) direction. In the case of identical thickness(400?nm) of ferroelectric layer, the PZT/BIT multilayer ferroelectric thin films showed a better ferroelectric property than PZT thin films. The clockwise rotational C\|V hysteresis loop of the Au/PZT/BIT/p Si heterostructure indicated that the PZT/BIT ferroelectric thin films had controlled the Si surface potential and showed a characteristic of polarization\|type switching. The current\|voltage ( I\|V ) curves showed that the heterostructure was conductive only in the one voltage direction and the leakage currents are too low to identify in the opposite direction. The conduction in low voltage region displays an ohmic behavior and the current transportation in ferroelectric thin films at the high voltage region is ascribed to the space\|charge limited current. The remnant polarization of the PZT/BIT films system remained tobe 90% of the initial value after 10\+9 bipolar switching cycles.更多还原