Technological Study of Fabrication of RF MEMS in Series

本文采用MEMS工艺制作接触式串联射频开关 ,射频开关采用双端固定的悬臂梁结构 ,悬梁为PECVD制作的SiN薄膜 ,溅射Au制作共平面波导 ,聚酰亚胺作为牺牲层 ,运用等离子体刻蚀法释放牺牲层。研究了悬梁、共平面波导以及电极的制作工艺 ,并分析了牺牲层的制作和刻蚀工艺对开关结构的影响。Fabrication technology of RF MEMS in series was studied.The fixed-fixed beam structure were used in the switches,which consist of SiN suspending membranes grown by plasma enhanced chemical vapor deposition(PECVD),co-planar wave-guide coated with gold film,and a polyimide sacrificial layer released by O 2 plasma etching.The fabrication of SiN membrane,the electrodes and the coplanar wave-guide were discussed,respectively.And how the growth of the sacrificial layer and the chemical etching affect the performance of switches was also discussed.国家自然科学基金青年基金资助项目 ( 60 3 0 10 0 6) ;; 福建省自然科学基金资助项目 (A0 3 10 0 12

Study on Mechanical Property of Silicon Nitride Thin Film and the Application in RF MEMS Switches

氮化硅薄膜具有致密的结构、高强度和良好的耐磨性能,可用于MEMS器件中作为结构部件.本文采用PECVD法制备氮化硅薄膜,对氮化硅薄膜的杨氏模量和硬度进行了测试,并分析了沉积温度、反应气体流量比对薄膜杨氏模量和硬度的影响.应用氮化硅薄膜作为悬梁,制作了射频MEMS开关.Silicon nitride thin film is often used in MEMS devices as structure part because of its high density and strength. The silicon nitride films were prepared by PECVD method. The test of Young’s Modules and hardness on silicon nitride films were carried on. The relationship between Young’s Modules, hardness and deposition temperature, reaction gas flow ratio was analyzed. The RF MEMS switch was fabricated using silicon nitride as fixed-fixed beam.国家自然科学基金资助(60301006);; 福建省科技重点项目资助(2005H029

Investigation for Metal Lift-off Process in RF MEMS Switch

研究用bP212正性光刻胶(浸泡氯苯)、AzP4620正性光刻胶(浸泡氯苯)、Az5214E反转光刻胶光刻后的图形剥离金属的难易度及图形质量.用扫描电镜(SEM)观察不同光刻胶及浸泡氯苯后的侧壁图形,并分析不同侧壁图形的形成机理,找出最佳工艺参数,并应用于射频MEMS开关制作中的金属剥离.The lift-off processes of BP212 positive photoresist(and chlorobenzene treatment) and AZP4620 positive photoresist(and chlorobenzene treatment) were studied.AZ5214E image-reversal photoresist was also studied.Side wall graphics were observed using scanning electron microscope(SEM).The forming mechanism of different lateral wall pattern was analysed.The optimum process parameters were found and used in metal lift-off in RF MEMS switches.国家青年基金资助项目(60301006);福建省自然科学基金资助项目(A0310012

The Study on Mechanical Properties of Thin Film in Micro-electromechanical Systems

主要介绍微机电系统(MEMS)中几种测量薄膜力学性能的方法,如纳米压入法、单轴拉伸法、基底弯曲法、微旋转结构法,比较了各种方法的优缺点。这对MEMS器件的设计与研究具有重要意义。Some methods of measuring mechanical properties of thin film in Micro-electromechanical systems are intro-duced including nanoindentation,single axial tension,wafer curvature,micro rotating structure,etc.Their advantages and disadvantages are compared.It is useful for the design and researchment of MEMS devices.国家基金青年基金(60301006);; 福建省自然科学基金(A0310012);; 国家留学基金项目资

The Application of Polyimide(PI) in the Manufacture Process of RF MEMS Capacitive Shunt Switch

聚酰亚胺树脂(PI)因其良好的平面化特性、在氧气中易灰化、不完全固化易溶解于碱性显影液、在CHF3等离子气氛中有较强的抗蚀性等性质,在电容RFMEMS开关的制作过程中,应用它作为刻蚀保护层和牺牲层,不但可以使工艺过程得到简化,而且可以对开关的介质层尺寸、牺牲层厚度等图形参数起到很好的控制作用.As a kind of polymer material, polyimide(PI) holds a favorable complanation property and is easy to become ash in the oxygen.PI also can resist ion etching produced by the CHF_3 plasma body and be easy to dissolve in alkali developer solution when it is not solidified completely.Basised on the properties mentioned above,PI can be used in the manufacture process of RF MEMS Capacitive Shunt Switch to achieve a precisely control on the size of dielectric layer,the thickness of sacrificial layer and some other graph parameters

Application of Si/Glass Bonding in the Facture of RF-MEMS Switches

介绍了一种新的RF-MEMS开关制作工艺,利用静电键合技术将表面微加工工艺与体硅加工工艺结合在一起完成开关上下电极的组合;说明了如何在普通环境下进行图形对准;通过静电力的理论计算和键合试验,分析了铝台阶对硅/玻璃静电键合的影响,得出铝台阶厚度低于100nm时键合效果较好;对有无铝台阶时的静电键合电流特性进行比较,分析了硅/玻璃界面电荷分布及其运动情况,为RF-MEMS开关的设计与制作提供了有意义的参考。Bulk micromachining processes and surface sacrificial processes were connected by Si/glass bonding for making RF-MEMS switches.How to align the mask at nomal condition was given.The theoretical calculations of the static force and lots of bonding experiments were done to prove the influence of Al in the Si/glass bonding,educing that better results of Al thickness below 100 nm.The current characteristic was compared in the electrostatic bonding with Al or not.The charge distribution and movement in the interface of silicon wafer and glass wafer was analyzed.Significant reference was provided for the design and manufacture of RF-MEMS switches.国家自然科学基金项目(60301006);; 福建省科技重点项目资助(2005H029

间充质干细胞在器官移植中发挥免疫抑制作用及机制探讨的研究进展

器官移植是终末期器官衰竭患者最有效的治疗手段。将间充质干细胞(MSC)用于器官移植已成为细胞疗法的重要组成部分。然而,MSC发挥免疫抑制作用的机制还有待进一步地挖掘,且影响MSC发挥免疫抑制作用的因素很多,这些原因导致MSC难以达到预期疗效。在本综述中将通过介绍MSC的免疫抑制作用及机制、影响MSC发挥免疫抑制作用的因素以及MSC的临床应用等方面来阐述MSC在器官移植领域的研究进展。国家重点研发项目(2018YFA0108304)国家自然科学基金(81771721、81671583

修士論文要旨 : H. 教育コミュニケーション情報科学研究領域

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Short-sales constraints and market efficiency: evidence from the Hong Kong market

The Best PhD Thesis in the Faculties of Architecture, Arts, Business & Economics, Education, Law and Social Sciences (University of Hong Kong), Li Ka Shing Prize, 2005-2006.abstractpublished_or_final_versionBusinessDoctoralDoctor of Philosoph