PZT热释电薄膜材料的研究

【作者】 彭家根；

【导师】 张树人；

【作者基本信息】 电子科技大学 ， 材料学， 2005， 硕士

【摘要】 近年来,铁电薄膜材料的制备、结构、性能和应用已经成为国际上新型材料研究的一个热点。由于铁电薄膜材料具有良好的压电、热释电、铁电、电光及非线性光学性能,可广泛应用于微电子机械系统、铁电存储器和热释电红外探测器等方面,因而受到广泛的关注。PZT 薄膜材料是目前研究较多的一类材料,它具有较高的自发极化、相对低的介电常数和损耗,是制备热释电薄膜非制冷红外探测器首选材料之一。本论文从实验上对PbZr0.3Ti0.7O3[PZT(30/70)]和PZFNT [Pb(Zr0.58Fe0.2Nb0.2Ti0.02)O3]薄膜的制备工艺、微结构以及性能进行了系统的研究。采用射频磁控溅射法在5 英寸的Pt/Ti/SiO2/Si 基片上制备了PZT 薄膜,并对薄膜进行快速退火处理。通过AFM 和XRD 的分析以及性能测试,结果表明:所制备的薄膜具有良好的介电、铁电和热释电性能,在优化条件下其热释电系数、介电常数、损耗、剩余极化以及探测优值分别为2.09×10-8C/cm2K、630、1.4%、26μC/cm2 和2.81×10-9Ccm/J,基本满足热释电器件对薄膜材料性能的要求。同时还得到了薄膜制备工艺参数对薄膜微结构和性能影响的一些规律。此外, 还采用RF 磁控溅射法在5 英寸的Pt/Ti/SiO2/Si 和PZT/Pt/Ti/SiO2/Si 基片上制备了PZFNT 薄膜,后处理采用快速退火工艺。对两种薄膜进行了分析,实验结果表明,采用PZT 缓冲层可明显降低PZFNT 薄膜的结晶温度,并对PZFNT 薄膜的性能有显著的影响,使其介电和铁电性能得到提高。在优化工艺条件下,可获得热释电系数为6.4×10-9C/cm2K,介电常数和损耗分别为1328 和3.1%,剩余极化为29.8μC/cm2 的铁电薄膜,该薄膜可望在铁电存储器和热释电红外探测器中得到应用。更多还原

【Abstract】 Recently, the fabrication, structures, properties and applications offerroelectric thin films have gained significance in the novel materials scienceall over the world. Frroelectric thin films have been paid much attection to fortheir good piezoelectric, pyroelectric, ferroelectric, electrooptic andnon-linear optical properties, and their applications in microelectromechanicalsystems, ferroelectric memories and pyroelectric detectors. PZT thin films arebeing investigated extensively in the ferroelectric materials. Because PZT thinfilms have large spontaneous polarization and small dielectric constant anddielectric loss, they are the appropriate materials for pyroelectric uncooledinfrared detectors. In this paper, the fabrication process, micro-structure andproperties of PbZr_0.3Ti_0.7O₃ [PZT（30/70）] and PZFNT[Pb(Zr_0.58Fe_0.2Nb_0.2Ti_0.02)O₃] thin films were systematically studied fromexperimental aspect.RF magnetron sputtering technology and the rapid thermal annealingprocess have been utilized to fabricate the PZT thin fims on 5-inchPZT/Pt/Ti/SiO₂/Si substrates. Analyses by the aid of atom force microscopy（AFM） and X-ray diffraction （XRD） and measurement reveal that the thinfilms have good dielectric, ferroelectric and pyroelectric properties in theoptimum process. And the thin films have the pyroelectric coefficient of 2.09×10^-8C/cm²K, dielectric constant of 630, dielectric loss of 1.4%, remanentpolarization of 26μC/cm² and figure of merit for detectivity of 2.81×10^-9Ccm/J, respectively. So the films are applicable for pyroelectricdevices. Meanwhile, the effects of parameters of the films fabricationprocess on the microstructures and properties of the thin films havebeen investigated.In additional, PZFNT thin films were fabricated on 5-inch Pt/Ti/SiO2/Siand PZT/Pt/Ti/SiO₂/Si substrates by a RF magnetron sputtering method andrapid thermal annealing process. By investigating the two thin films at various更多还原