PREPARATION OF PIEZOELECTRIC PZT THIN FILMS BY HYBRID PROCESSING

采用溶胶凝胶法和激光烧蚀法在Pt/Ti/SiO_2/Si衬底上制备了Pb(Zr_xTi_<1-x>)O_3 （PZT）薄膜。在Pt/Ti/SiO_2/Si衬底上采用激光烧蚀法直接沉积薄膜时，复合工艺的沉积后退火温度较低。通过溶胶-凝胶法沉积的层可以控制混合处理得到的薄膜的优选取向。混合法制备的薄膜由（111）择优取向的钙钛矿相组成，具有良好的铁电性能。研究了Zr/Ti比对PZT薄膜电学性能、晶体结构和微观结构的影响。结果表明，由Zr/Ti比为45/55的靶材制备的PZT薄膜比由Zr/Ti比为52/48的靶材制备的PZT薄膜具有更好的电性能，其组成接近于致形相边界复合材料。透射电镜图像显示，薄膜具有沿薄膜厚度延伸的多晶柱状微观结构，溶胶-凝胶法和激光烧蚀法制备的膜层之间没有明显的界面。HTEM图像还显示，各层的晶格是连续的，并且在厚度上没有差异。用溶胶-凝胶法和激光烧蚀法得到层间的晶体取向。结果表明，溶胶-凝胶法制备的下层PZT为激光烧蚀法制备的上层PZT的结晶提供了种子层。溶胶-凝胶法沉积的PZT层与激光烧蚀层之间的固相外延效应降低了沉积后退火的温度，并且可以利用溶胶-凝胶法沉积的PZT层控制PZT膜的首选取向。在应用中，采用三掩模光刻工艺成功地设计并制作了PZT薄膜驱动的微镜。在测量的谐振频率下驱动器件时，演示了扫描性能。少

Thin films of Pb(Zr_xTi_<1-x>)O_3 (PZT) were prepared by hybrid processing (sol-gel method and laser ablation) on Pt/Ti/SiO_2/Si substrates. The temperature of post-deposition annealing in hybrid processing is lower than that in the case of direct film deposition by laser ablation on a Pt/Ti/SiO_2/Si substrate. The preferred orientation of the films derived by hybrid processing can be controlled using the layer deposited by the sol-gel method. The films fabricated by hybrid processing consist of the perovskite phase with a (111)-preferred orientation and have good ferroelectric properties. The effect of Zr/Ti ratio on the electrical properties and crystal structure as well as microstructure of the PZT films was investigated, too. It was found that the PZT films derived from the target with a Zr/Ti ratio of 45/55 exhibited better electric properties than that derived from the target with a Zr/Ti ratio of 52/48, and their composition was close to the morphotropic phase boundary compositi … More on. The transmission electron microscopy image showed that the films had a polycrystalline columnar microstructure extending through the thickness of the film, and no sharp interface was observed between the layers obtained by the sol-gel method and laser ablation. The HTEM image also revealed that the crystalline lattice of the layers was continuous and there was no difference in. crystalline orientation between the layers obtained by the sol-gel method and laser ablation. These results indicated that the lower PZT layer deposited by the sol-gel method acted as a seed layer for the crystallization of the upper PZT layer deposited by laser ablation. The solid-phase epitaxial effect between the PZT layers deposited by the sol-gel method and laser ablation lowers the temperature of postdeposition annealing, and the preferred orientation of the PZT films can be controlled using the layer deposited by the sol-gel method. In the application, the micromirror actuated by the PZT film was designed and fabricated successfully with three-mask lithography process. The scanning performance is demonstrated while driving the device at the measured resonant frequency. Less