一种硅四层键合的高对称电容式加速度传感器

提出了一种利用体微机械加工技术制作的硅四层键合高对称电容式加速度传感器.采用硅/硅直接键合技术实现中间对称梁质量块结构的制作,然后采用硼硅玻璃软化键合方法完成上、下电极的键合.在完成整体结构圆片级真空封装的同时,通过引线腔结构方便地实现了中间电极的引线.传感器芯片大小为6.8mm×5.6mm×1.68mm,其中敏感质量块尺寸为3.2mm×3.2mm×0.84mm.对封装的传感器性能进行了初步测试,结果表明制作的传感器漏率小于0.1×10-9cm3/s,灵敏度约为6pF/g,品质因子为35,谐振频率为489Hz.     

一种硅四层键合的高对称电容式加速度传感器

提出了一种利用体微机械加工技术制作的硅四层键合高对称电容式加速度传感器.采用硅/硅直接键合技术实现中间对称梁质量块结构的制作,然后采用硼硅玻璃软化键合方法完成上、下电极的键合.在完成整体结构圆片级真空封装的同时,通过引线腔结构方便地实现了中间电极的引线.传感器芯片大小为6.8mm×5.6mm×1.68mm,其中敏感质量块尺寸为3.2mm×3.2mm×0.84mm.对封装的传感器性能进行了初步测试,结果表明制作的传感器漏率小于0.1×10-9cm3/s,灵敏度约为6pF/g,品质因子为35,谐振频率为489Hz.     

圆片级真空封装技术在MEMS陀螺中的应用

为维持MEMS硅微陀螺的真空度,利用两次硅-玻璃阳极键合和真空长期维持技术,实现了MEMS硅微陀螺的圆片级真空气密性封装。制作过程包括:先将硅和玻璃键合,在硅-玻璃衬底上采用DRIE工艺刻蚀出硅振动结构;再利用MEMS圆片级阳极键合工艺在10-5 mbar(1 mbar=100 Pa)真空环境中进行封装;最后利用吸气剂实现圆片的长期真空气密性。经测试,采用这种方式制作出的硅微陀螺键合界面均匀平整无气泡,漏率低于5.0×10-8 atm.cm3/s。对芯片进行陶瓷封装,静态下测试得出品质因数超过12 000,并对样品进行连续一年监测,性能稳定无变化。     

一种新颖的基于MEMS技术的光读出热成像系统性能分析与制作

提出了一种新颖的光读出红外热成像系统设计 .该系统利用光学读出技术将红外图像直接转化为可见光图像 ,其核心部件是一个基于微电子机械技术 (MEMS)制作的法布里 泊罗 (Fabry Perot)微腔红外探测器列阵 (F PMCIRDA) .通过对Au/SiNx双材料体系的理论分析 ,得出了可动微镜的最大热 机械灵敏度、机械 光灵敏度及其温度响应分别为 6 .4 7× 10 -9m/K、1.5 3× 10 8m-1、2 .0 5× 10 -4.对系统噪声分析表明 :在目前的设计中 ,系统的噪声等效温差 (NETD)为 5 .1K ,而其极限值有望达到 5 8mK .采用体硅MEMS工艺 ,制作出了 5 0× 5 0的Fabry Perot微腔列阵 .实验表明 ,在红外辐射作用下 ,可动微镜有明显的位移 ,验证了工作原理     

硅微机械二维倾角传感器结构设计

提出了一种结构简单,制造工艺容易实现的硅微机械二维倾角传感器结构设计,它由蝶形质量块和连接它们的四个成十字形的硅应变梁以及具有过载限位保护功能的硼硅玻璃衬底构成.传感器能同时检测出绕两轴的倾角变化.分析了硅应变梁的受力情况,得到了与倾角的解析关系,并用有限元方法验证了结果,理论灵敏度为0.75 mV/ °.     

硅热电堆探测器件及制作

针对实现红外技术在夜间和一些死角方面应用的视觉辅助系统,把微机械加工技术和制作微细红外吸收膜的工艺应用到CMOS技术中,使热电堆实现了高性能化.利用运用PSG替代层的分离法制作用低压真空蒸镀法成膜的金黑膜,使吸收膜实现了微细化.制作出三种160 μm见方的原型传感器,它们在大气中的灵敏度分别达到300 V/W、149 V/W、60 V/W,响应时间常数达2 ms、0.46 ms、0.27 ms.还利用原型传感器制成了64×32像元焦平面列阵传感器(FPA).     

基于MEMS的硅微压阻式加速度传感器设计

硅微加速度传感器是MEMS器件中的一个重要分支,具有十分广阔的应用前景。由于硅微加速度传感器具有响应快、灵敏度高、精度高、易于小型化等优点,而且该种传感器在强辐射作用下能正常工作,因而在近年来发展迅速。文章首先对传感器结构及工作原理进行了简单介绍,给出了一种基于MEMS技术制作的压阻式硅微加速度传感器的结构和工艺,并对制作的加速度传感器样品进行了动态测试,测试结果表明与理论设计值基本吻合。     

采用PVDF薄膜的单片热释电红外图像传感器

研制出了16×16像元的单片热释电红外图像传感器.该图像传感器的特征是利用电子溅射法制作PVDF热释电膜,利用埋沟MOSFET制作低噪声探测器,利用微机械加工制作由四条横梁支撑的薄膜结构的热绝缘结构.探测部大小为75 μm见方、调制频率为55 Hz的图像传感器,其电压灵敏度达到6600 V/W,比探测率达1.6×107cmHz1/2·W-1,成功地获得了黑体炉开口部的热图像.虽然在灵敏度误差、噪声、偏置电压方面还存在着问题,但在实现单片热释电红外图像传感器方面已看到了前景.     

一种简单的静电封接技术

本文论述了静电封接技术的基本原理及其在半导体压力传感器生产中的应用.主要介绍一种简单而廉价的静电封接装置及操作工艺和一些实验结果.这种封接技术不用其它任何粘合剂,将硅与玻璃相接触进行静电封接,形成的硅-玻璃组合体是一种刚性结构.封接时所选用的玻璃的热膨胀系数应与硅的热膨胀系数相接近(Si:2.5×10~(-6)/ k,~#7740 Pyrex glass:3.25×10~(-6)/k),例如:九五料玻璃,派雷克斯玻璃均能获得好的封接效果.静电封接技术的特点是:芯片反刻铝引线不会被氧化(封接时温度在400℃左右),封接牢固、迅速、气密性好,不产生蠕变,能耐高温,耐潮湿,稳定性好.     

纳米多晶硅薄膜压力传感器制作及特性

给出一种纳米多品硅薄膜压力传感器,采用LPCVD法在衬底温度620℃时制备纳米多晶硅薄膜,基于MEMS技术在方形硅膜不同位置制作由4个薄膜厚度为63.0nm的掺硼纳米多晶硅薄膜电阻构成惠斯通电桥结构,实现对外加压力的检测.实验结果表明.当硅膜厚度75μm时,纳米多晶硅薄膜压力传感器在恒压源5.0V供电时,满量程(160kPa)输出为24.235mV,灵敏度为0.151mV/kPa,精度为0.59%F.S,零点温度系数和灵敏度温度系数分别为-0.124%/℃和-0.108%/℃.     

点目标成像红外遥感器探测信噪比测试研究

针对遥感器真空低温测试需求，设计并搭建了一套能够在低温真空环境中稳定工作的红外目标背景模拟器，模拟器主要由冷光阑、真空低温面源黑体、三维电移台三部分组成，冷光阑模拟探测背景，冷光阑上分布微孔用于模拟探测点目标。通过有效控制目标模拟器与背景模拟器间的隔热、控温以及背景模拟器与待测遥感器之间的隔热，实现稳定测试。另外，将仿真优化与实践经验相结合，通过仿真计算去除模拟器冷光阑板厚度、目标相位、平行光管等的影响，有效降低系统测量不确定度。文中的仿真分析方法和验证情况对于红外遥感器点目标探测信噪比检测试验具有参考意义。     

非本征光纤F-P干涉声传感器的研究

为研究不同材料对法布里-珀罗(F-P)干涉声传感器性能的影响。采用几种不同金属材料,设计制作了基于光纤端面—膜片非本征型F-P干涉声传感器,利用有限元方法对圆形振动膜片进行模态分析,得到了一阶固有频率。实验结果表明:由金、锌合金材料制作的传感器可探测较低声压,且传感器灵敏度较高、对外界声波信号响应成良好的线性关系。     

Surface Micromachined Pressure Sensor with Internal Substrate Vacuum Cavity

A surface micromachined piezoresistive pressure sensor with a novel internal substrate vacuum cavity was developed. The proposed internal substrate vacuum cavity is formed by selectively etching the silicon substrate under the sensing diaphragm. For the proposed cavity, a new fabrication process including a cavity side‐wall formation, dry isotropic cavity etching, and cavity vacuum sealing was developed that is fully CMOS‐compatible, low in cost, and reliable. The sensitivity of the fabricated pressure sensors is 2.80 mV/V/bar and 3.46 mV/V/bar for a rectangular and circular diaphragm, respectively, and the linearity is and for these two diaphragms. The temperature coefficient of the resistances of the polysilicon piezoresistor is to per degree of Celsius according to the sensor design. The temperature coefficient of the offset voltage at 1 atm is 0.0019 mV and 0.0051 mV per degree of Celsius for a rectangular and circular diaphragm, respectively. The measurement results demonstrate the feasibility of the proposed pressure sensor as a highly sensitive circuit‐integrated pressure sensor.     

基于进口膜片的光纤光栅压力传感器的研究

分析了光纤布喇格光栅(FBG)的压力传感特性,给出了FBG的中心波长与压力的关系以及压力灵敏度系数的表达式,并将FBG纵向粘贴在富士公司生产型号为FBC 20WB2的膜片上进行了压力实验。实验结果表明粘贴在FBC 20WB2型膜片上的FBG压力传感器的灵敏度系数为0.376 nm/MPa左右,其测量精度在满量程范围内为1%,而理论的压力灵敏度系数为0.385 nm/MPa。同时发现粘贴在该膜片上的FBG压力传感器的中心波长与压力变化有着良好的线性关系和很高的相关系数并且迟滞现象较小,说明基于该膜片的FBG压力传感器非常适合于压力测量。     

Polycrystalline silicon solar cells on metallurgical silicon substrates

The use of a polycrystalline silicon p-n junction structure deposited on low-cost substrates is a promising approach for the fabrication of low-cost solar cells. Metallurgical-grade silicon, with a purity of about 98% and a cost of about $1/kg, was cast into plates in a boron nitride container and used as substrates for the deposition of solar cell structures. The substrates were polycrystalline with millimeter size crystallites. Solar cells of the configurations n>⁺-silicon/p-silicon/metallurgical silicon and n⁺-silicon/p⁺-silicon/metallurgical silicon were prepared by the thermal decomposition of silane and the thermal reduction of trichlorosilane containing appropriate dopants. The AMO efficiencies of n⁺-silicon/p-silicon/metallurgical silicon solar cells were up to 2.8% (with no anti-reflection coatings) and were limited by the grain boundaries in the p-layer. The grain boundary effects were reduced by increasing the dopant concentration in the p-layer, and AMO efficiencies of about 3.5% were obtained from n⁺-silicon/p⁺-silicon/metallurgi silicon solar cells.     

一种微型光纤光栅压力传感器

设计并实现了一种新型光纤光栅压力传感器。该传感器以光纤布拉格光栅(FBG)为敏感元件,通过菱形钢结构,将压力转换为膜片横向应变,通过将光纤光栅粘于工形膜片中心轴线上,可将压力转换为光纤光栅轴向应变,通过解调光栅的中心波长漂移即可得到压力大小。传感器外壳采用圆柱体刚性封装,外高为13mm,直径为33mm。对设计的传感器进行了压力标定测试,得出传感器的线性拟合度为0.993 5,量程为0~0.234MPa,灵敏度为3.341nm/MPa。     

Mesa Diaphragm-Based Fabry-Perot Optical MEMS Pressure Sensor

An optical micro electron mechanical system （MEMS） pressure sensor with a mesa membrane is presented. The operating principle of the MEMS pressure sensor is expatiated by the Fabry-Perot （F-P） interference and the relation between deflection and pressure is analyzed. Both the mechanical model of the mesa structure diaphragm and the signal averaging effect is validated by simulation, which declares that the mesa structure diaphragm is superior to the planar one on the parallelism and can reduce the signal averaging effect. Experimental results demonstrate that the mesa structure sensor has a reasonable linearity and sensitivity.     

Conduction properties of silicon dioxide in oxide-nitride-oxide structures

Conduction properties of silicon dioxide have been investigated in polysilicon-oxidized silicon nitride (top-oxide)-silicon nitride-silicon dioxide (bottom-oxide)-silicon structures with various nitride and top-oxide thicknesses. Oxidized silicon nitride was found to exhibit electron tunneling limited (Fowler-Nordheim-type) conduction. Electron Fowler-Nordheim conduction in the relatively thick (⋍ 100 Å) bottom-oxide was verified down to very low electric fields (⋍ 5 MV/cm).     

Characterization of a silicon-based shear-force sensor on human subjects

A silicon sensor is developed and its ability to measure both compressive and shear forces at the skin-object interface is characterized. The sensor is designed based on the piezoresistive effect and fabricated using integrated circuit and microelectromechanical systems technologies. The sensor utilizes a mesa structure that leads to asymmetric diaphragm deformations in response to nonnormal loading. Four independent ion-implanted piezoresistors are used to detect the stresses induced in diaphragm and resolve both the compressive- and shear-force components. The sensor is calibrated on human subjects over a range of applied force (5- to 40-N shear force at increments of 1.25 N; 0- to 30-N compressive force). Force measurement via a tracking experiment is evaluated at four shear (9, 18, 25, and 35 N) and three compressive (7, 15, and 26 N) force levels. The sensor has good repeatability (SD approximately 1.7 N) with an average error of 12.1%.     

Effects of Unphysiological Factors on Cardiac Output Regulation During Artificial Heart Pumping

Several Factors affecting artificial heart output were studied employing two mathematical models of prosthetic hearts, i.e., sac and diaphragm heart models. The stroke volume sensitivity to changes in venous pressure was analyzed by numerical computations. Increased inflow valve resistance, increased pump vacuum pressure, decreased elasticity of the ventricular sac or diaphragm and decreased size of the ventricle were shown to depress artificial heart function. In total prosthetic heart replacement experiments in calves, the resistance at the junction of the right heart to the natural atrium was measured by varying the pump vacuum pressure. When the vacuum pressure exceeded ?20 mmHg, the orifice resistance to flow increased approximately 4 times. Optimizing the above factors, a prosthetic heart should be designed that provides sufficient flow with a pump vacuum pressure not greater than ?20 mmHg.