Studies On The Fabrication, Structure And Pyroelectric Properties Of PZT Thin Films

Because of the excellent dielectric, ferroelectric, pyroelectric properties, PZT thin films are widely used in microelectronics, optoelectronics, integrated optics and micro-electro-mechanical systems. It is the ideal material for control section on ferroelectric memories, infrared detectors and micro-accelerometer. It is crucial to control the structure of PZT films for their future applications due to their strong anisotropic structure. And this is on the point of orientation, crystallinity, electrical properties issue. In this paper,the preparation of PZT thin films, properties and application issues have been carried out.In this paper, perovskite-type PZT52/48 thin films were successfully prepared by sol-gel method. Further more, the annealing temperature was confirmed through DTA analyzing. And the annealing manner was confirmed by AFM as rapid thermal annealing. The surface topography and structure of PZT thin films which fabricated at different annealing temperatures were tested. The results shown that at the annealing temperature of 700℃, PZT thin films had good crystallization and <100>-oriented. Through Raman analyzing, eight modes of PZT thin films were obtained. The trigonal phase was turned to tetragonal phase as the temperature increased. The electrical properties of PZT thin films with different thickness were succeeded obtained. The 616nm thin films expressed a good ferroelectric hysteresis graph, the residual polarization was 25μC/cm -2. The dielectric properties shown that the dielectric constant and dielectric loss raised as the thickness increase. The dielectric tunability of PZT thin films was also studied. And the PZT thin films of 616nm shown the best dielectric tunability.The surface morphology, structural characteristics and electrical properties of PZT thin films were tested in this paper. The differences on structure, ferroelectric and dielectric properties of PZT thin films with different annealing temperatures and thickness were analyzed. The experimental results shown that 700℃was the satisfactory annealing temperature, and the PZT thin films of 616nm had good electrical properties. In addition, the infrared-sensitive structure based on PZT sensitization unit was studied. The testing system was designed. And the thermal response was tested. The voltage response signal was successful picked up. This result proved that PZT thin films exhibited good pyroelectric characteristics and response ability. In addition, the parameters of PZT thin films were analyzed that affect the voltage response rate. This dissertation provided a good foundation for application studies in infrared sensors based on PZT thin films.