PZT铁电薄膜的低温制备及其微图形加工

锆钛酸铅(PZT)铁电薄膜具有高的剩余极化强度和机电耦合系数,是制备各种传感器和存贮器优良的功能材料。在器件的制备工艺中,需要将PZT铁电膜沉积到单晶Si基板上,但是,PZT过高的结晶温度会严重地破坏Si基板。为了降低PZT的结晶温度,使用紫外光辅助热处理技术对PZT前驱体薄膜进行预处理,可以将PZT的结晶温度降低至475℃,从而实现PZT薄膜的低温制备。在紫外光的预处理过程中,通过光源与PZT膜中的有机基团发生光化学作用,从而形成不溶于溶剂的活性单体,通过溶剂的清洗,可以实现对前驱体膜的微加工,形成PZT阵列,为制备高密度存贮器所需要的逻辑阵列提供了有意义的探索。     

Sol-Gel法硅基铁电薄膜研究

介绍了用溶胶 凝胶方法制备Pb(Zr0 .53Ti0 .4 7)O3(PZT)铁电薄膜的工艺流程。以硝酸锆、醋酸铅和钛酸四丁酯为原料 ,在 90 0℃ ,30min退火条件下制备了硅基PZT铁电薄膜。实验分析结果显示 ,PZT铁电薄膜的晶化很完善。研究了PZT铁电薄膜与硅之间的界面及其对铁电薄膜品质的影响。并在此基础上实现了制备PZT铁电薄膜的低温改进工艺。     

铁电膜层制备技术研究现状

具有铁电性且厚度在数十纳米至数微米的铁电薄膜具有良好的压电性、介电性及热释电性等特性,在微电子、光电子和微电子机械系统等领域有着广阔的应用前景.随着铁电薄膜制备技术的发展,使现代微电子技术与铁电薄膜的多种功能相结合,必将开发出众多新型功能器件,促进新兴技术的发展,因此对铁电薄膜的研究已成为国内、国际上新材料研究中的一个十分活跃的领域.在铁电薄膜的许多应用中,铁电存储器尤其引人注目.如何制备性能良好的铁电薄膜,满足集成铁电器件的要求成为制约铁电薄膜应用的关键环节,薄膜制备技术的进步可以提高铁电薄膜的质量,目前人们已经能够使用多种方法制备优良的铁电薄膜.总体来说,制备铁电薄膜按其制膜机理大体上可分为化学沉积法和物理沉积法两大类.化学沉积法制备微纳铁电薄膜,通过对薄膜成分、元素掺杂及薄膜取向等方面的研究提高铁电薄膜的性能,从而制备出高质量的薄膜.物理沉积法一般是在较高的真空度下进行,采用不同的基片和调节基片的温度可制得不同取向的薄膜,甚至外延薄膜,这种方法对自发极化呈现高度各向异性的薄膜制备显得尤为重要.热喷涂方法制备厚涂层通过从元素掺杂、热处理、工艺参数优化等方面来改善铁电涂层的性能.铁电薄膜制备技术的进步可以提高薄膜的质量,而薄膜质量的提高又可以促进功能器件制备技术的进步、使用性能的提升,从而使其得到更广泛的应用.本文综述了近年来铁电薄膜制备技术及其应用研究的新进展,主要针对化学方法、物理方法及热喷涂方法制备铁电薄膜的技术难点讨论了铁电薄膜成形的物理化学机理、优缺点及其应用情况.     

锆钛酸铅铁电薄膜电容的研究现状

介绍了Pb(Zr,Ti)O3,(PZT)铁电薄膜电容的研究现状,列举了不同电极和缓冲层所制备出的PZT铁电薄膜电容的结构,并对不同结构进行了分析比较,结果表明由于氧化物电极材料的各种优越性,已被证明可用于替代现有的金属电极材料,从而有效解决了PZT薄膜铁电性能退化的问题,是未来铁电薄膜电容的发展方向.     

SOL-GEL方法制备PZT铁电薄膜新方法及铁电特性研究

我们用SOL-GEL方法对PZT的制备进行了深入细致的研究,PZT薄膜不同组分的加入顺序对铁电特性的影响较小,而精确地控制PZT铁电薄膜的组分是制备性能良好的铁电薄膜的关键,铁电薄膜的退火条件对铁电薄膜特性有着至关重要的影响.我们运用将Zr及Ti有机物溶液加入Pb的有机溶液的新的制备工艺流程以精确地控制Pb/Zr/Ti的组分,从而制备出性能良好的铁电薄膜.在大量实验的基础上,我们绘制出扩散炉和快速热退火时,钙钛矿的形成与退火温度及时间的关系图,并且得出PZT铁电薄膜最佳的退火温度和时间区域.     

铁电薄膜退火方法的研究

以锆钛酸铅薄膜（PZT）为例，分析了国内外铁电薄膜退火的各种方法。针对解决铁电薄膜基底高温生长工艺与硅集成电路承受温度较低的不兼容及器件性质劣化的难题，分别对普通炉子退火、快速热退火及激光退火进行了详细的分析比较。激光低温退火技术有望成功地在未来应用PZT铁电薄膜制作组件时，增加其制备工艺设计的弹性和可行性。     

择优取向铁电薄膜制备影响因素的分析

制备性能优良、高度择优取向或外延生长、成分均匀、结构可控的晶态铁电薄膜材料，是发展铁电薄膜应用的基础。随着铁电薄膜在微电子学，光电子学和集成光学等领域的应用不断扩大，如何制备高性能的铁电薄膜材料一直称为人们关注的热点。对择优取向铁电薄膜材料制备技术中的主要影响因素进行了分析，希望能为从事此方面工作的研究者提供一定的借鉴。     

新型PST铁电薄膜的制备及其电性能研究

PST铁电薄膜是一种具有优良铁电、热释电和介电等性能的铁电材料.该材料在红外探测器、红外焦平面阵列、热成像器件、非易失性铁电存储器和大容量电容器等方面具有广泛的应用.PST铁电薄膜的制备方法多种多样,各具优缺点,不同的制备工艺对薄膜的性能有影响.叙述了PST铁电薄膜的制备技术、电性能和在热释电红外探测器方面的应用.     

SO1-Gel法硅基PZT铁电薄膜研究

介绍了以硝酸锆、醋本以铅和钛酸四丁酯为原料用溶胶－凝胶（sol-gel）方法在硅衬底上制备Pb（Zr0.53Ti0.47)O3(PZT)铁电膜的工艺流程。对铁电薄膜的表面形貌、晶化程度、界面状态等性质进行了分析,结果表明硅基PZT薄膜形成了良好的钙伏矿结构,并在此基础上实现了制备PZT铁电薄膜的低温改进工艺。     

力电多场鼓包法测定PZT铁电薄膜的横向压电系数

为表征Pb(Zr_(0.52)Ti_(0.48))O_3(PZT)薄膜的横向压电性能,以纯力场鼓包测试模型和铁电薄膜材料压电方程为基础,推导了PZT铁电薄膜的力电耦合鼓包本构模型。采用溶胶-凝胶法制备了PZT铁电薄膜,并通过化学腐蚀法获得PZT薄膜鼓包样品。在外加电压为0~14V的条件下进行鼓包测试。结果表明,在纯力场作用下,PZT薄膜的弹性模量和残余应力分别为91.9GPa和36.2MPa;随着电压从2V变化到14V,PZT薄膜的横向压电系数d31从-28.9pm/V变化到-45.8pm/V。本工作所发展的力电耦合鼓包测试技术及力电耦合鼓包本构模型为评价铁电薄膜材料的横向压电性能提供了一种有效的分析方法。     

铁电薄膜的制备及应用技术研究

研究出具有特色的制备铁电薄膜的 sol-gel技术;制备出高质量、高可靠的 PLT、PZT、PYZT、BST”l、PbTiO3、BaTiO3、Bi4Ti3O12多晶铁电薄膜,PLT、PZT和伽里O3异质外延生长铁电薄膜;研制出铁电薄膜热释电单元红外传感器,8元、9元、1O元线列和8X8元阵列;研制出热释电火情探测器和热释电非接触式温度测试仪。     

Sol-Gel法制备PZT铁电薄膜新进展

从底电极的选择、过渡层的引入、外延膜的生长、取代阳离子的改性四个方面介绍了Sol-Gel法制备PZT铁电薄膜的研究进展,简述了PZT的Sol-Gel机理研究现状和引起PZT铁电薄膜极化疲劳的原因,分析了Sol-Gel法制备PZT铁电薄膜研究中存在的问题,并提出展望。     

锆钛酸铅(PZT)薄膜的制备及其改性研究

文章综述了锆钛酸铅(PZT)薄膜的主要制备方法,其中包括射频磁控溅射法、脉冲激光沉积法、溶胶-凝胶法和金属有机化学气相沉积法。讨论了不同工艺参数对于PZT薄膜的结构和性能的影响,并针对PZT薄膜出现的疲劳现象进行掺杂改性,探讨提高其抗疲劳性能的途径。     

Corona poling of highly (001)/(100)-oriented lead zirconate titanate thin films

Corona poling is an interesting non-contact poling process for ferroelectric materials which, has in the past, been extensively applied to ferroelectric polymers, but not to other types of ferroelectric materials. Here, it has been investigated as an alternative technique to the conventional direct-contact poling of ferroelectric thin films.

Contact-poling and corona poling techniques were applied to highly (001)/(100) oriented lead zirconate titanate thin films of composition 52% Zr, 48% Ti (PZT52/48). Different poling voltages and durations were used to pole the samples, and the effects on the piezoelectric coefficients e_31,f and d_33,f were explored. From the magnitudes of piezoelectric coefficients and suppression of e_31,f relative to d_33,f, it was concluded that corona poling is a more suitable technique for poling PZT52/48 thin films than direct poling, since piezoelectric coefficients were higher and sample damage was less for corona poling when compared with contact-poling.     

溅射工艺参数对PZT铁电薄膜相变过程的影响

采用射频磁控溅射工艺,在（１１１）Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上用ＰＺＴ（５３／４７）陶瓷靶制备铁电薄膜。用快速光热退火炉对原位沉积的薄膜进行ＲＴＡ处理。     

Fabrication of single crystal PZT thin films on glass substrates

 We have successfully transferred heteroepitaxial Pb(Zr,Ti)O₃ (PZT) thin films from MgO substrates on to glass substrates. The transferred PZT thin films exhibit single crystal structure with ferroelectric properties similar to the as-grown epitaxial films. The transferring process comprises coating of Cr-metallized surface of epitaxial PZT thin films, pressing and cementing the Cr-metallized surface on to the glass substrates by silicone rubber, and removing the MgO substrates by chemical etching. This process realizes a fabrication of high-temperature processed PZT thin films onto the glass at room temperature. The process is also available for the transformation of PZT thin films on organic film sheet. The present transfer process reduces the effects of the inevitable strain and/or constraint to rigid substrates for heteroepitaxial growth and has a potential for integration of single crystal piezoelectric PZT devices onto a wide variety of MEMS.     

Electrical and reliability properties of PZT thin films for ULSI DRAM applications

The electrical and reliability characteristics of ferroelectric capacitors fabricated using sol-gel derived 50/50 lead-zirconate-titanate (PZT) thin films have been examined for ULSI DRAM (dynamic random access memory) applications. Various electrode materials, film thicknesses (200 nm to 600 nm) and capacitor areas were used. A large stored-energy density (Q(c)) of 15 muC/cm(2) (at 125 kV/cm) was measured using different methods. The results indicate that PZT thin films exhibit material properties which might satisfy the requirements of ULSI DRAMs.     

Fabrication and characterization of piezoelectric micromachined ultrasonic transducers with thick composite PZT films

Ferroelectric microelectromechanical systems (MEMS) has been a growing area of research in past decades, in which ferroelectric films are combined with silicon technology for a variety of applications, such as piezo-electric micromachined ultrasonic transducers (pMUTs), which represent a new approach to ultrasound detection and generation. For ultrasound-radiating applications, thicker PZT films are preferred because generative force and response speed of the diaphragm-type transducers increase with increasing film thickness. However, integration of 4- to 20-microm thick PZT films on silicon wafer, either the deposition or the patterning, is still a bottleneck in the micromachining process. This paper reports on a diaphragm-type pMUT. A composite coating technique based on chemical solution deposition and high-energy ball milled powder has been used to fabricate thick PZT films. Micromachining of the pMUTs using such thick films has been investigated. The fabricated pMUT with crack-free PZT films up to 7-microm thick was evaluated as an ultrasonic transmitter. The generated sound pressure level of up to 120 dB indicates that the fabricated pMUT has very good ultrasound-radiating performance and, therefore, can be used to compose pMUT arrays for generating ultrasound beam with high directivity in numerous applications. The pMUT arrays also have been demonstrated.     

Ferroelectric films for non volatile-memory applications

Microelectronic applications of ferroelectric thin films have undergone a resurgence. Recent advances in deposition technologies and the achievement of bulk properties in thin films have enabled successful integration and fabrication of ferroelectric random access memories onto standard integrated circuits that combine high speed, complete non-volatility and extreme radiation hardness. Current research covers both the basic and applied areas in ferroelectric material science and semiconductor device development. In this talk the evolution of solid state memory devices in conjunction with silicon technology will be described, and the increasingly important role expected from ferroelectric materials highlighted. In coupling ferroelectric thin film processing with Si technology several new problems have to be resolved. The device physics and design, the material choice for ferroelectric memories, thin film preparation and characterization, and the problems of fatigue and retention will be discussed.