含NiTi阻挡层的硅基(La_(0.5)Sr_(0.5))CoO_3/Pb(Zr_(0.4)Ti_(0.6))O_3/(La_(0.5)Sr_(0.5))CoO_3铁电电容器异质结

(La_(0.5)Sr_(0.5))CoO_3/Pb(Zr_(0.4)Ti_(0.6))O_3/(La_(0.5)Sr_(0.5))CoO_3 Capacitor Heterostructure Integrated on Si with NiTi Barrier Layer

应用磁控溅射法制备的非晶NiTi薄膜作阻挡层,在Si(100)衬底上构造了(La0.5Sr0.5)CoO3/Pb(Zr0.4Ti0.6)O3/(La0.5Sr0.5)CoO3(LSCO/PZT/LSCO)铁电电容器异质结,研究了Pb(Zr0.4Ti0.6)O3铁电薄膜的结构和物理性能。实验发现LSCO/PZT/LSCO铁电电容器具有良好的电学性能,在417kV/cm的驱动场强下,PZT铁电电容器具有较低的矫顽场强(125kV/cm)和较高的剩余极化强度(19.0μC/cm2),良好电容-电压特性(C-V)和保持特性,铁电电容器经过1010次反转后,极化强度没有明显下降,表明了非晶NiTi薄膜可以用作高密度硅基铁电存储器的扩散阻挡层。

（ La0.5 Sr0.5 ） CoO3/Pb （ Zr0.4 Ti0.6 ） O3/（ La0.5 Sr0.5 ） CoO3 （ LSCO/PZT/LSCO ） ferroelectric capacitor heterostructure was fabricated on Si （100） using amorphous NiTi film as diffusion barrier layer, in which both LSCO and NiTi films were prepared by magnetron sputtering, and PZT was prepared using sol-gel method. Structural and physical properties of LSCO/PZT/LSCO heterostructure were characterized by X-ray diffraction and ferroelectric tester. It is found that LSCO/PZT/LSCO capacitor, measured at 417kV/cm, possesses very good ferroelectric properties, such as small coercive field （125kV/cm） ,high remnant polarization （ 19.0μC/cm^2 ）, and good capacitance-voltage characteristic. Polarization of LSCO/ PZT/LSCO ferroelectric capacitor doesn＇ t degrade after 10^10 switching cycles, which indicates that amorphous NiTi is an ideal candidate for diffusion barrier for the high-density ferroelectric random access memories integrated with silicon transistor technology.