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.     

原子层沉积技术及其在铁电薄膜制备中的应用

讲述原子层沉积技术原理与特点的同时,进一步论述了它在沉积机理和实验真空度这两方面与传统薄膜沉积工艺的异同;综述了此技术在铁电薄膜制备研究方面的最新进展,前驱体的制备与选择、薄膜缺陷的控制以及表面化学反应动力学依然是当前原子层制备铁电薄膜研究的重点;最后展望了原子层沉积技术制备铁电薄膜的发展方向.     

介电/半导体功能集成薄膜的制备和特性调控

介电/半导体功能集成薄膜,主要是指将具有电、磁、声、光、热等功能特性的介电功能材料(主要是氧化物类介电功能材料)与硅、砷化镓或氮化镓等典型半导体类功能材料,以单层薄膜或多层薄膜的形式生长(甚至外延生长)在一起而形成的人工新材料,这类新材料有可能具有多功能一体化和功能特性之间的相互调制及耦合等特点,可望在新型电子和光电子器件中获得应用.介绍了介电/半导体功能集成薄膜产生的背景;从集成铁电薄膜与器件、HK/半导体集成薄膜与器件以及极性氧化物/GaN功能集成薄膜与器件等3个方面,分别介绍了介电/半导体功能集成薄膜的应用;概括介绍了介电/半导体功能集成薄膜的制备方法及特性调控.     

PZT薄膜在MEMS器件中的研究进展

主要介绍在MEMS器件中PZT薄膜制备的方法、制备过程中需要解决的问题、PZT薄膜与MEMS的集成以及PZT在MEMS中的应用的研究进展,并展望了PZT薄膜的应用前景.     

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。     

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.     

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。     

用溶胶—凝胶法制备铁电薄膜

介绍了溶胶－凝胶技术制备铁电薄膜的基本原理，工艺过程及工艺特点，综述了溶胶－凝胶法制备铁电薄膜的最新进展。     

微弧氧化法及其在铁电薄膜制备中的应用

介绍了微弧氧化法的基本原理和工艺过程;综述了微弧氧化法制备铁电薄膜的发展历程及最新研究进展;讨论了目前微弧氧化制备铁电薄膜过程中存在的主要问题;提出了合理选择溶液体系和溶液浓度,研究工艺参数对薄膜表面形貌和铁电、介电性能的影响,提高薄膜表面质量是促进微弧氧化制备铁电薄膜技术发展的关键。     

原子层沉积技术及其在铁电薄膜制备中的应用

讲述原子层沉积技术原理与特点的同时，进一步论述了它在沉积机理和实验真空度这两方面与传统薄膜沉积工艺的异同；综述了此技术在铁电薄膜制备研究方面的最新进展，前驱体的制备与选择、薄膜缺陷的控制以及表面化学反应动力学依然是当前原子层制备铁电薄膜研究的重点；最后展望了原子层沉积技术制备铁电薄膜的发展方向。     

Advanced fabrication and characterization of epitaxial ferroelectric thin films and multilayers

Understanding the behavior of ferroelectrics on the nanoscale level requires the production of materials of the highest quality and advanced characterization techniques for probing the fascinating properties of these systems with reduced dimensions. Here we give an overview of our recent achievements in this area, which includes the detailed study of the suppression of ferroelectricity in PbTiO3 thin films, the fabrication of PbTiO3/SrTiO3 superlattices in which ferroelectricity shows some surprising behavior, and finally the manipulation of nanoscale ferroelectric domains using the atomic force microscope which leads to the precise analysis of domain wall creep and roughness in Pb(Zr,Ti)O3 thin films.     

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.     

Structural Characterization of Sputtered Fe70Pd30 Thin Films During Ex Situ and In Situ TEM Heating

Magnetic shape memory (MSM) thin films have been investigated for their use as actuators and sensors in micro‐electro‐mechanical systems (MEMS). Here, we report on the fabrication of polycrystalline Fe₇Pd₃ thin films by magnetron sputtering. Two‐dimensionally structured, freestanding films can be obtained by the use of different lift‐off techniques and optical lithography. The effect of different heat treatments is discussed. In situ transmission electron microscopy of the as deposited films up to 850 °C shows intermediate phases during heating. Significant changes in magnetic properties of the intermediate phases are observed in complementary investigations on ex situ annealed freestanding films.     

RF sputtering: A viable tool for MEMS fabrication

Fabrication of Micro-Electro-Mechanical-Systems (MEMS) requires deposition of films such as SiO₂, Si₃N₄, ZnO, polysilicon, phosphosilicate glass (PSG), Al, Cr-Au, Pt, etc. for use as structural, sacrificial, piezoelectric and conducting material. Deposition of these materials at low temperature is desirable for fabricating sensors/actuators on temperature-sensitive substrates and also for integrating MEMS structures on silicon in post-CMOS processing procedures. Plasma enhanced chemical vapour deposition (PECVD) and sputtering are amongst potential techniques for preparing films for MEMS fabrication at comparatively low temperatures. The sputtering technique has an added advantage that the process is carried out in an inert ambient (argon) and chemically sensitive substrate/sacrificial layers can be used in realization of MEMS. Furthermore, the same system can be used for depositing dielectric, piezoelectric and conducting materials as per requirement in the fabrication sequence. This enables rapid low-cost prototyping of MEMS with minimum fabrication facilities. In the present work, we report preparation, characterization and application of RF sputtered SiO₂, Si₃N₄ and ZnO films for MEMS fabrication. The effect of RF power, sputtering pressure and target-to-substrate spacing was investigated on the structural and other properties of the films. The residual stress in the films was obtained usingwafer curvature measurement technique. The deposition parameters are optimized to obtain low stress films of SiO₂ and Si₃N₄. The self-heating of the substrate during deposition was advantageously exploited to obtain highly c-axis oriented films of ZnO without any external heating. A variety of MEMS structures such as cantilever beams, micro-bridges, diaphragms, etc. are demonstrated using bulk, surface and surface-bulk micromachining techniques.     

用喷雾热分解方法制备PZT薄膜及其铁电特性的研究

用喷雾热分解方法制备PZT薄膜,由TGA和DTA确定其退火温度,由XRD和SEM研究其结构特性,用电容-电压技术研究其铁电特性,研究发现：Sawyer-Tower桥测定的C-V曲线与电容-电压技术的结果不同,其铁电性质如电滞回线、Ec和Pr、回线中心的位移、对称性等依赖于测量频率。     

PLZT铁电薄膜的物理特性研究

铁电薄膜是近几年人们关注的功能材料。本文对用溶胶－凝胶技术制备的ＰＬＺＴ铁电薄膜从热处理工艺、Ｘ射线结构分析、ＦＴ－ＩＲ红外光谱等各个方面作了较为系统的研究。讨论了ＰＬＺＴ铁电薄膜的热处理工艺条件,结构特性、光谱特性与材料的表观裂纹、晶态与非晶态之间的关系。对红外光谱的特征吸收峰作了指认,得到了一系列有意义的结果。     

PECVD法生长氮化硅工艺的研究

采用了等离子体增强化学气相沉积法(plasma-enhanced chemical vapor deposition,PECVD)在聚酰亚胺(polyimide,PI)牺牲层上生长氮化硅薄膜,讨论沉积温度、射频功率、反应气体流量比等工艺参数对氮化硅薄膜的生长速率、氮硅比、残余应力等性能的影响,得到适合制作接触式射频MEMS开关中悬梁的氮化硅薄膜的最佳工艺条件.     

MEMS领域中形状记忆合金薄膜的研究与进展

总结了近年来微机电系统(MEMS)领域中,ti-Ni形状记忆合金(SMA)薄膜的制备与微加工工艺、形状记忆性能、加工性能、防腐耐磨性能及力学性能的研究进展,由此提出了MEMS领域中,SMA薄膜的使用要求和研究方向.