双层金属化工艺中绝缘介质的SEM研究

本文介绍了扫描电子显微镜(SEM)的器件剖面分析技术，并对双层金属化工艺中的技术难点进行了分析和研究。     

OLED器件技术及产业化进展

有机电致发光器件OLED驱动电压低、发光亮度大、视角宽、响应速度快、制作工艺简单,在未来的平板显示领域显示了诱人的应用前景,也是21世纪首选的绿色照明光源之一。本文论述了有机电致发光器件结构和材料及其发光原理,介绍了有机电致发光器件的技术及产业化进展,讨论了有机电致发光器件发展存在的问题与突破。     

碳化硅直接键合机理及其力学性能研究

随着碳化硅(SiC)材料的MEMS器件在恶劣环境测量中的应用前景和迫切需求,进行了碳化硅的直接键合实验.研究了工艺条件对键合样品力学性能的影响,同时借助激光共聚焦扫描显微镜(CLSM)、扫描电子显微镜(SEM)、能谱仪(EDS)和拉曼光谱仪等对碳化硅键合样品界面的微观结构进行了分析.结果表明:退火温度和加载压力是影响键合效果的关键性因素.当退火温度为1 300℃,加载压力为3 MPa和退火时间为3 h时,此时键合样品的气密性非常好,力学性能达到最佳,键合强度2 MPa.最后通过样品微观界面分析表明碳化硅直接键合的机理为界面氧化硅过渡层的形成及粘性流动与碳化硅和碳化硅的熔融直接键合.     

ZnO薄膜的制备技术与应用领域

ZnO是一种新型的Ⅱ-Ⅵ族宽禁带(3.37eV)化合物半导体材料,具有较高的激子束缚能(室温下为60meV)和光增益系数320cm-1,是一种理想的短波长光电器件材料,在蓝紫光发光二极管(LEDs)和激光器(LDs)等领域有巨大的应用潜力。该文就ZnO薄膜的制备方法和应用做一简要综述。     

基于MOCVD生长材料的高电流密度太赫兹共振隧穿二极管

为获得高功率的太赫兹共振隧穿器件,优化设计了AlAs/InGaAs/AlAs共振遂穿二极管材料结构,在国内首次采用MOCVD设备在半绝缘InP单晶片上生长了RTD外延材料。利用接触光刻工艺和空气桥搭接技术,制作了InP基共振遂穿二极管器件。并在室温下测试了器件的电学特性:峰值电流密度>400 kA/cm~2,峰谷电流比(PVCR)>2.4。     

一种碳化硅器件的测试技术研究

鉴于碳化硅材料在集成电路领域的巨大优势，为进一步提高电路研发生产水平，形成高效而完善的器件测试流程，以某款碳化硅器件为测试对象，为其专门设计一套测试方法。方法基于对碳化硅材料的特性与工作原理的分析，合理选取测试条件与测试设备，并实际进行测试，获得击穿电压、正向电流、结电容等参数的详细数据。测试结果表明，方法能够准确把握该类碳化硅产品的关键参数指标，符合行业标准，具有一定的实用价值。     

一种双端排布热电堆结构设计与仿真优化

微机电系统（MEMS）红外热电堆是光谱仪、气体传感器、远程温度传感器等现代信息探测系统的核心工作器件,较高的表面利用率和响应度以及更简易的制备工艺将是未来该类器件制造技术的发展趋势。本文分别采用热偶条双端对称排布、取消红外吸收区、扩大冷端欧姆接触面积、支撑膜边缘开通绝热槽、充分发挥氮化硅钝化与红外吸收双功能作用等设计理念,对热偶条温差分布进行优化,研究热电堆性能的变化规律。采用Ansys workbench有限元分析软件对器件进行仿真发现：当传感器设计尺寸为1.5mm×1.5mm×0.3mm,有效面积1.21mm2,绝热槽1.1mm×20μm时,双端开槽的热电堆探测器在具备更低制备成本的同时表现出最优性能表现。通过与普通双端热电堆性能进行仿真对比,发现绝热槽的引入使得探测器输出电压提升88.5%。为未来温度传感器设计制造提供了新颖的设计思路。     

DB—1型半导体材料禁带宽度测试装置

一、引言半导体技术的发展必须依赖于半导体材料的发展。禁带宽度是决定半导体材料特性的一个重要参数。该参数的测定在进一步研究半导体材料的能带结构、导电特性和加快半导体技术的发展等方面具有重要的意义。DB—1型半导体材料禁带宽度测试装置的研     

铁电材料的光伏效应调控又有新方法

光伏效应广泛存在于BaTiO3、Pb（Zr,Ti）O3等铁电材料中。由于较大的禁带宽度,铁电材料的光电转换效率通常较低。新型铁电材料BiFeO3因其禁带宽度相对较窄,人们在这种材料中发现了明显的光伏效应。相比单晶块体和外延薄膜材料,多晶BiFeO3薄膜因其制备工艺简单、     

Ti-Al金属化结构

金属化系统对于器件及其半导体的成品率和可靠性有着密切的联系。随着半导体集成电路的集成度不断提高,应用范围不断扩大,其重要性更加显著,因而受到人们很大的关注,据美国72年公布的硅平面管失效情况来看,因金属化系统效占28％.整机失效分析表明,在潮湿气氛中因A1受到腐蚀以及受到大电流冲击时金属化系统引起失效所占的比例,比上述系统还要大。所以如何提高金属化系统的性能对器件乃至整机都是重要的。本文仅根据我们对Ti-Al金属化结构的试制工作作一简单介绍,较深入的问题,可以参阅有关文献和书籍,这里不再赘述。     

Reliability of Pt ohmic contact on an undoped 3C-SiC micro-electrothermal device

The objective of this paper is to investigate the reliability of platinum (Pt) ohmic metallization on an undoped 3C-SiC. The Pt layer is deposited on a SiC fabricated microcantilever using focused ion beam technique. The purpose of the Pt layers is to act as electrodes to generate electrothermal actuation from joule effect. The results showed an excellent ohmic contact formation. Over a period of storage at room temperature, deterioration of the ohmic contact had occurred. The effect of Schottky contact on the required power was also investigated by observing the decrease in the magnitude of the electrothermally vibrating device. An increase of resistance from 1 KΩ to few hundred KΩs was also reported.     

Wafer-level bonding and direct electrical interconnection of stacked 3D MEMS by a hybrid low temperature process

The presented fabrication technology enables the direct integration of electrical interconnects during low temperature wafer bonding of stacked 3D MEMS and wafer-level packaging. The low temperature fabrication process is based on hydrophilic direct bonding of plasma activated Si/SiO₂ surfaces and the simultaneous interconnection of two metallization layers by eutectic bonding of ultra-thin AuSn connects. This hybrid wafer-level bonding and interconnection technology allows for the integration of metal interconnects and multiple materials in stacked MEMS devices. The process flow is successfully validated by fabricating test structures made out of a two wafer stack and featuring multiple ohmic electrical interconnects.     

High power devices in wide bandgap semiconductors

Silicon carbide (SiC) semiconductor devices for high power applications are now commercially available as discrete devices. Recently Schottky diodes are offered by both USA and Europe based companies. Active switching devices such as bipolar junction transistors (BJTs), field effect transistors (JFETs and MOSFETs) are now reaching the market. The interest is rapidly growing for these devices in high power and high temperature applications. The main advantages of wide bandgap semiconductors are their very hi...     

Fabrication and testing of micromachined silicon carbide and nickelfuel atomizers for gas turbine engines

Bulk micromachining of high-temperature materials is an enabling technology for the application of MEMS devices in high-temperature environments. This paper presents a novel molding method for fabricating silicon carbide (SiC) fuel atomizers for gas turbine engines. The devices are compared to similar nickel (Ni) atomizers fabricated using the LIGA process. Performance and erosion tests demonstrate that both types of atomizers are able to perform well at pressures in excess of 2500 kPa, with the SiC devices exhibiting a higher erosion resistance. The results demonstrate a significant improvement over similar silicon (Si) devices, which are limited in operation to pressures below 1400 kPa and are comparatively not resistant to erosive wear     

Reverse analysis via efficient artificial neural networks based on simulated Berkovich indentation considering effects of friction

Instrumented indentation test has become a popular method for characterization of materials of small volume such as those constitute the micro-electro-mechanical devices, micro-electronic packages and thin film. Berkovich indenter is one of the most popular indenter tips employed in the tests. The present study involves the finite element simulation of indentation by Berkovich-family of indenters to establish the load-displacement relations for elasto-plastic materials obeying power law. Effects of friction at the contact surfaces, which have been ignored by most of the researchers are considered in the analyses. Extensive 3-dimensional finite element analyses covering a wide practical range of materials have been carried out and the results adopted for material characterization via artificial neural network model based on an efficient reverse analysis algorithm. Direct mapping of the characteristics of the indentation curves to the material properties are performed and the characteristics of the network model deliberated. The tuned network can then be adopted to predict the mechanical properties of a new set of materials of small volume in micro-electro-mechanical components.     

SiC薄膜高温压力传感器

SiC是制造高温半导体压力传感器的理想材料。介绍了在Si衬底上外延生长 3C -SiC薄膜和用它制作的SiC高温压力传感器 ,并对研制结果进行了分析。简单介绍了其它几种SiC压力传感器的特点、结构和制作方法。     

Fabrication of comb-drive micro-actuators based on UV lithography of SU-8 and electroless plating technique

Comb-drive microactuators are widely used in MEMS devices. Most of the comb-drive microactuators reported in MEMS field are made using fabrication technology with silicon as the structural material. Recent progress in ultra violet (UV) lithography of SU-8 has made it feasible to fabricate ultra high aspect ratio microstructures with excellent sidewall quality. In this paper, a research work on fabrication and metallization of high aspect ratio SU-8 polymer comb-drive microactuators was reported. The fabrication process combined multi-step and multi-layer UV lithography of SU-8 on a silicon substrate and copper electroless plating to selectively metallize the SU-8 microstructure. The selective electroless plating was achieved by using UV modification of the SU-8 microstructures and the careful control of the exposure dosage. Preliminary experimental results have proved the feasibility of the microactuator and the fabrication technology.     

New thermoelectric components using microsystem technologies

This paper describes the first thermoelectric devices based on the V-VI-compounds Bi/sub 2/Te/sub 3/ and (Bi,Sb)/sub 2/Te/sub 3/ which can be manufactured by means of regular thin film technology in combination with microsystem technology. Fabrication concept, material deposition for some 10-/spl mu/m-thick layers and the properties of the deposited thermoelectric materials will be reported. First device properties for Peltier-coolers and thermogenerators will be shown as well as investigations on long term and cycling stability. Data on metal/semiconductor contact resistance were extracted form device data. Device characteristics like response time for a Peltier-cooler and power output for a thermogenerator will be compared to commercial devices.     

Femtosecond laser fabrication and characterization of microchannels and waveguides in methacrylate-based polymers

Femtosecond laser ablation is a promising method for producing polymeric microfluidic devices: it is a high precision processing technology resulting from an efficient energy deposition, while simultaneously minimizing heat conduction and thermal damage to the surrounding material. This work reports on the characterization of microchannels and waveguides fabricated by femtosecond laser technology in methacrylate-based polymers, precisely in thermoplastic poly(methyl methacrylate) (PMMA) and in a new material based on a high efficiency UV-curing process of methacrylic monomers bearing hydrophilic polyethylene glycol chains, namely tetraethylene glycol dimethacrylate and poly(ethylene glycol) methacrylate (PEG-MA). Microchannels in PMMA and PEG-MA, fabricated by parallel multi-scans, have sharp edges and low roughness, as investigated by Environmental Scanning Electron Microscopy and laser profilometer. Surface and physico-chemical properties after fs-laser processing were further studied by contact angle measurements and Attenuated Total Reflectance FTIR spectroscopy. Moreover, preliminary tests showed the refractive index of fs-laser PEG-MA exposed zones is different with respect to that of the surrounding polymer, suggesting that PEG-MA can be a good candidate to manufacture microfluidic devices containing integrated optic elements.     

紫外光电探测器研制

采用宽带隙半导体材料SiC,进行紫外光电探测器的制备。基于机械性能和化学稳定性考虑,增透抗反膜的制备采用SiO2＋Al2O3工艺,同时对其表面钝化层和增透抗反膜工艺进行了研究讨论。