Au/PZT/BIT/p-Si异质结的制备与性能研究

采用脉冲激光沉积(PLD)工艺,制备了以Bi₄Ti₃O₁₂(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(Zr_0.52Ti_0.48)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530℃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 关键词： 铁电薄膜 异质结构 脉冲激光沉积(PLD)

PREPARATION AND CHARACTERIZATION OF THE Au/PZT/BIT/p-Si HETEROSTRUCTURE

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 10⁹ bipolar switching cycles.
Keywords： ferroelectric thin films heterostructure PLD