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.     

铁电薄膜及铁电存储器的研究进展

铁电薄膜是具有铁电性且厚度尺寸为数纳米到数微米的薄膜材料,因其在非挥发性铁电随机存储器方面的潜在应用而受到广泛关注.综述了新型无铅、无疲劳Bi4Ti3O12(BIT)基铁电薄膜材料的制备和改性及性能表征方法,阐述了铁电薄膜的3种失效机制及铁电薄膜存储器的研究现状,最后提出了铁电薄膜及存储器今后可能的研究方向.     

铁电存储器集成工艺中关键技术研究进展

铁电薄膜与半导体集成技术相结合而发展起来的铁电存储器与传统的半导体存储器相比有很多优点,其关键集成工艺技术有铁电薄膜制备技术、电极制备、刻蚀技术、氢阻技术、金属互连技术、钝化技术.简要介绍了这些工艺技术的研究现状,并讨论了相关工艺对性能的影响.     

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。     

Sol-Gel法制备PLZT系铁电薄膜

介绍了Sol-Gel法，并对近年来Sol-Gel法制备PLZT系铁电薄膜材料的有关研究进行了分析和总结，详细介绍了Sol-Gel法制备PLZT系铁电薄膜材料的各种原料及工艺流程。     

铁电薄膜与集成铁电学

评述了铁电薄膜制备技术的发展现状及存在的问题，简介了铁电存储器、铁电薄膜红外探测器、光波导、微驱动器等集成铁电学器件的研制及对材料、工艺的要求，提出了集成铁电学发展中有待研究的一些问题。     

铁电薄膜研究的一些新动向

从Ｙ１铁电薄膜材料、外延铁电薄膜、介电超晶格、铁电薄膜的制备工艺及原位检测几个方面介绍了铁电薄膜研究的一些新动向。     

金属有机化学气相沉积制备铁电薄膜材料研究进展

铁电薄膜是一类重要的功能材料,是近年来高新技术研究的前沿和热点之一.金属有机化学气相沉积(MOCVD)是制备铁电薄膜的一种重要方法.综述了金属有机化学气相沉积法制备铁电薄膜的历史、原理、工艺参数、特点和采用此方法制备出的某些材料的铁电性能.     

无铅铁电／压电薄膜材料的研究进展

微电子技术的迅猛发展和集成化程度的急速提升，致使铁电／压电薄膜材料愈来愈受到人们的关注与重视。本文从三方面介评了铅基和铋类铁电／压电薄膜材料的研究进展：（1）主要制备方法：脉冲激光熔融法（PLD）和金属有机物分解法（MOD）；（2）无铅铁电／压电薄膜微器件：铁电薄膜存储器和压电薄膜传感器；（3）铁电／压电薄膜及其微器件的可靠性。     

铁电薄膜及其在存储器件中的应用研究现状

概述了铁电薄膜在非易失存储器中的应用研究现状,将铁电存储器与其他类型存储器进行了比较,针对铁电薄膜在存储器中的应用,探讨了铁电薄膜制备工艺与半导体工艺兼容性、极化疲劳、尺寸效应等几方面的问题,指出了当前研究的重点.     

Processing dependences of microstructure of ferroelectric thin films

Ferroelectric thin film has been widely investigated in detail in recent years. The ferroelectric properties of thin films are obviously dependent on the microstructure of the film, which is influenced by some processing parameters for preparing the films, including precursor solution chemistry, nature of substrate, film thickness, and condition of heat treatment etc. In this paper, these processing dependences of the films are reviewed.     

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.     

Amorphous ferroelectric thin film capacitive device for hydrogen detection

Hydrogen is a promising alternative energy source for next generation automobile engines that meet the concern of energy shortage and global environmental pollution. Hydrogen detection is an important associated technology to be developed. The recently developed amorphous ferroelectric thin film capacitive gas sensors with a largely improved sensitivity to hydrogen show a great potential for this associated technology. This review presents an overall picture of amorphous ferroelectric thin film hydrogen gas sensors. It focuses on the correlation among processing, microstructural evolution and electrical properties of amorphous ferroelectric thin films. An attempt is made to detail the hydrogen sensitivity and transient response of various prototype capacitive devices with respect to the quality of the films and the hydrogen kinetic processes in the Pd/ferroelectric heterostructure. Recent advances on the hydrogen interface-blocking model for amorphous ferroelectric gas sensors are also described.     

Laser transfer processing for the integration of thin and thick film ferroelectrics

Laser transfer processing (LTP) offers the potential to overcome the problems of integrating ferroelectric thin and thick film materials with polymers and other technologically useful substrate materials that cannot sustain the high process temperatures, 600–1,000 °C, required for normal film deposition. The LTP technique involves the fabrication of a ceramic film on a high-temperature substrate material such as sapphire, and subsequent release by application of pulsed ultra-violet laser radiation. Here, the LTP technique is reviewed in the context of ferroelectric thin and thick films, and current developments are presented. Micro- and nanostructural features of the films before and after transfer to a second substrate are revealed using scanning and transmission electron microscopy. The consequences of laser-generated structural changes on ferroelectric properties are illustrated, and measures to mitigate the effects of an amorphous damage-layer are discussed.     

PZT纳米晶薄膜的Sol—Gel法制备及铁电性质

采用Ｓｏｌ－Ｇｅｌ法，以Ｚｒ的硝酸盐替代醇盐，引入ＰｂＴｉＯ３过渡层的方法成功的制备了纳米晶铁电薄膜。并进行了差热、热重、结构、组分、铁电性能的测定、分析。     

结构设计对铁电薄膜系统电滞回线的影响

为制备符合Si集成铁电器件要求的高质量Si基铁电薄膜，采用溶胶—凝胶(sol—gel)工艺，制备了MFM及MFS结构的铁电薄膜系统，研究了不同结构及不同衬底对铁电薄膜系统铁电性能及电滞回线的影响，并对这些差异产生的主要影响因素进行了分析，在此基础上，提出并制备了Ag／Pb(Zr0.52Ti0.48)O3／Bi4Ti3O12／p—Si多层结构，该结构铁电薄膜系统的铁电性能及电滞回线的对称性有明显改善，有望应用于Si集成铁电器件。     

Pb O3 成分梯度铁电薄膜的结构及性能

采用Sol-Gel方法,通过快速热处理,在Pt/Ti/SiO₂/Si衬底上制备出Pb (Zr, Ti) O₃成分梯度薄膜。用俄歇微探针能谱仪 (AES) 对制备的上梯度薄膜进行了成分深度分析,证实其成分梯度的存在。XRD分析表明,制备的梯度薄膜为四方结构和三方结构的复合结构,但其晶面存在一定的结构畸变。介电温谱测试表明,随着温度的升高,梯度薄膜出现一个铁电-铁电相变点和两个居里点,同时出现一定的频率弥散现象。不同偏压下电滞回线的测试表明,梯度薄膜表现出良好的铁电性质。热释电性能测试表明,梯度薄膜的热释电系数随着温度的升高逐渐增加,并且其热释电系数比每个单元的热释电系数大。      

Application of the X-ray combined analysis to the study of lead titanate based ferroelectric thin films

Lead titanate based ferroelectric thin films are well known for their excellent piezo and pyroelectric properties. In order to obtain a complete characterisation of the structural, micro structural and texture parameters of these films, a recently developed combined analysis of the X-ray diffraction data is carried out. The advantages of this approach reside in the fact that we obtain simultaneously quantitative and more reliable information of these parameters than with more conventional methods. Results obtained for ferroelectric thin films are analysed and compared with those obtained with other methods of analysis. The conclusions show that the texture of the films obtained with the combined method is able to separate the contributions of close texture components, like 〈100〉 and 〈001〉, or to study components with low contribution to the texture of the film.     

Progress of (Sr,Ba) TiO<Subscript>3</Subscript> ferroelectric thin film and tunability

The fabrication method, technology route and structure performances of (Sr, Ba) TiO₃ (SBT) ferroelectric thin film have been summarized in this paper. The tunability of dielectric constant, dielectric loss and leakage current are the basic parameters of tunable microwave devices. The thin films of SBT with high properties could be fabricated by means of RF magnetron sputtering and sol- gel processing. The electrical performances of thin film material can be improved largely by dopants. Some problems are put forward to pay attention to this material research process.