电容式加速度传感器设计及工艺加工北大核心

针对精确制导的应用需求,设计了一种量程为100g"三明治"电容式加速度传感器,通过ANSYS仿真软件在100g及10 000g高过载条件下进行应力分析和模态分析,并通过Matlab分析、优化结构参数从而确定传感器敏感结构的具体尺寸。利用阻抗分析仪分析得到了传感器的静态电容为14.09 pF,结构输出灵敏度为0.281 8 pF/g,传感器的输出灵敏度为13.5μV/g。根据结构特性设计工艺流程并进行关键工艺加工:硅基质量块双面湿法腐蚀、ICP干法刻蚀及玻璃通孔电镀工艺。最终,通过实验验证电容式加速度传感器设计的可行性。     

一种光强差分调制MOEMS加速度计

针对传统微光机电系统(MOEMS)光学加速度传感器结构复杂、信号解算繁琐等缺点,该文设计了一种基于绝缘衬底上的硅(SOI)片上工艺的,光强差分测量加速度的MOEMS加速度计。该传感器的主要光强调制部件为90°V型镜,在V型镜的对应位置上集成3个光纤通道,入射光经V型镜反射后进入2条输出光纤通道。加速度信号由进入2条光纤通道的光强差检测。器件的所有部分集成在单一的SOI晶圆片上,由一次深刻蚀工艺制造。与传统传感器比较,具有工艺简单、抗电磁干扰和有效抑制共模信号等优势。加速度计的性能指标:微机械灵敏度为0.077 7μm/g(g=9.8m/s~2),谐振频率为1.79kHz,传感器灵敏度为5.46mV/g。     

基于无源RFID的集成加速度传感器设计

针对射频识别技术(RFID)迅猛发展的需求,采用0.35μm CMOS工艺设计并制造了一种集成加速度传感器。加速度传感器单元利用基于深反应离子干法刻蚀的体硅正面加工工艺,在经过标准IC工艺之后进行两步干法刻蚀,工艺简单。集成接口电路采用了一种内部限幅的环形振荡器电路,将加速度传感器电容值转换为频率信号,并由计数器完成数字信号输出转换。后期测试结果显示,所设计的集成加速度传感器获得了良好的线性度和稳定性能,仅占用0.23mm2芯片面积,1.2V电源电压下消耗了1.4μW功率,尤其适合于无源RFID传感器标签设计中。     

新型L形梁压阻微加速度传感器

介绍了一种新型的基于MEMS体硅加工工艺的L形粱压阻微加速度传感器.在加工过程中采用Si-Si直接键合完成底板与传感器支撑框体之间的粘合,使得后续加工工艺更加简单;采用DRIE释放梁结构,从而保证了梁结构的完整性.分析了该传感器的结构参数和灵敏度,并用ANSYS进行了有限元模拟,同时介绍了其工艺流程,以及封装后的测试结果.芯片尺寸为3.8 mm×3.8 mm×0.82 mm,其中敏感质量块尺寸为2 mm×2 mm×0.4 mm,梁尺寸为2 200μm×100 μm×40μm.经初步测试,在采用5 V电源供电时灵敏度为0.5 mV/g左右,3 dB截止频率为520 Hz左右.     

新日本无线公司推出两款新型放大器

新日本无线公司不久前推出用于加速度传感器、振动传感器和光传感器信号处理的单通道低噪声C M O S运算放大器N J U7009。NJU7009是对运算放大器的输入电路进行了"低电压工作时的噪声特性"改善的单通道CMOS运算放大器,同时实现了低工作电压(2.2V￣5.5V)、低工作电流(330μA,VDD     

电容式加速度计单芯片开环检测电路的研制

针对MEMS电容式加速度传感器,成功地研制出了一种单芯片集成检测电路。与国内常用的闭环结构不同,本电路采用的是开环检测电路。当电源电压为5V时,测得系统功耗为9 mW,灵敏度为15.8mV/g,线性误差为1.8%,噪声电压的峰峰值小于200μV(12.6 mg),测量范围为+/-100g。     

一种电容间隙精确可控的高对称加速度传感器

提出了一种高对称电容式微加速度传感器,该传感器为硅四层键合三明治结构,在完成传感器整体结构制作的同时,实现了圆片级真空封装。利用多次氧化的方法,既精确控制了加速度传感器的初始电容间距,又实现了限位凸点的制作。该加速度传感器的谐振频率为657Hz,品质因子为198,灵敏度为0.59V/g。     

基于GMR效应的新型生物传感器研究

制备出了结构为Ta/NiFe/CoFe/Cu/CoFe/MnIr/Ta,磁阻变化达9.2%的GMR自旋阀传感器,并用该种传感器对浓度为200μg/mL、直径2μm的生物免疫磁球溶液进行了检测。实验结果表明,该生物传感器可以对被测生物免疫磁球溶液产生平均350μV的电压输出信号,随着磁球溶液的继续增加,电压输出信号可以达到最大值450μV。除去背景干扰信号的影响,由磁球产生的有效电压输出信号为300μV。此外,交流励磁场的频率的增加也会使输出电压信号减小。     

悬臂梁式硅微加速度传感器的设计仿真

文章利用ANSYS软件对悬臂梁式硅微加速度传感器敏感芯片进行了设计仿真，给出了一种能满足，量程50g，精度10^-3要求的硅微加速度传感器的结构，并对加工时可能引入的工艺误差所带来的影响进行了讨论。     

基于GMR效应的新型生物传感器研究

制备出了结构为Ta/NiFe/CoFe/Cu/CoFe/MnIr/Ta，磁阻变化达9.2%的GMR自旋阀传感器，并用该种传感器对浓度为200μg/mL、直径2μm的生物免疫磁球溶液进行了检测。实验结果表明，该生物传感器可以对被测生物免疫磁球溶液产生平均350μV的电压输出信号，随着磁球溶液的继续增加，电压输出信号可以达到最大值450μV。除去背景干扰信号的影响，由磁球产生的有效电压输出信号为300μV。此外，交流励磁场的频率的增加也会使输出电压信号减小。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.