二维电容式硅微加速度传感器的刚度求解

硅微电容式加速度传感器具有灵敏度高、噪音低、漂移小、功耗低、结构简单等优点,在军民两用市场中有着广泛的应用前景.本文针对自主开发设计的一种带折叠梁的二维叉指电容式硅微加速度传感器,采用力法求解了其主轴刚度,为进一步研究该二维微加速度传感器的动态响应特性提供了理论依据.     

二维电容式硅微加速度传感器的刚度求解

硅微电容式加速度传感器具有灵敏度高、噪音低、漂移小、功耗低、结构简单等优点，在军民两用市场中有着广泛的应用前景。本文针对自主开发设计的一种带折叠梁的二维叉指电容式硅微加速度传感器，采用力法求解了其主轴刚度，为进一步研究该二维微加速度传感器的动态响应特性提供了理论依据。     

微加速度传感器折叠梁刚度的精确求法

通过采用结构力学的力法，建立了求解叉指式微结构加速度传感器刚度的力学模型，并得到了精确解。与材料力学方法相比，该模型推导过程简单；与有限元方法相比，该模型在同等力学假设的条件，精度更高，且将计算分析的工作效率大大提高。     

硅微电容式加速度传感器结构设计

通过建立传感器的力学模型,对硅微电容式加速度传感器的特性作了详细的分析与讨论,为系统结构的优化设计提供了理论基础。     

微硅隧道加速度传感器设计

比较了压阻式、电容式和隧道式加速度传感器的特点 ,提出了扭摆式隧道加速度传感器的结构 ,给出了工作原理和设计模型 ,最后给出了结构尺寸、版图总图及试制的芯片照片。     

新结构的硅一体化微加速度传感器

本文介绍了一种新结构的硅一体化微加速度传感器，理论和实验结果表明，这种传感器与传统硅微机械结构加速度传感器相经具有温度特性好，工艺简单和成品率高等优点，这种结构特别适合制作谐振传感器。     

扭摆式微硅隧道加速度传感器

本文介绍了扭摆式隧道加速度传感器的结构、工作原理、简化的力学模型,设计了版图、工艺流程及关键工艺,并制备出样品,最后给出测试电路和结果。     

微硅加速度传感器的发展

本文介绍了微硅加速度传感器自六、七十代发展至今,其代表产品的特点,对微硅加速度计三种典型代表形式进行了分析、指出其优缺点,并对目前微硅加速度计的发展趋势－检测空间加速度的三维加速度计进行了重点讨论。     

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。     

硅微加速度传感器的对称梁岛结构设计

采用有限元方法，针对硅微加速度传感器的对称梁岛结构进行了力学特性分析，通过分析得出了该结构的尺寸对其位移量、谐振频率及模态振型的影响规律，为此类加速度传感器的设计提供参考。     

一种高分辨率电容微加速度计的设计研究

分析了影响加速度计分辨率的因素,在此基础上,通过采用深度反应离子刻蚀工艺获得大的敏感质量和小的电极间隙、采用电容变化量比枝齿梳状敏感结构大一倍的直齿梳状敏感结构和利用静电负刚度来降低结构的刚度等措施提高器件分辨率。最后给出了一种新的设计方案,叙述了其工作原理并分析了影响其闭环灵敏度的因素。     

电磁驱动电容检测微机械陀螺的设计

介绍了一种电磁驱动电容检测微机械陀螺的结构和工作原理。该陀螺的突出优点在于驱动和检测采用了相互独立的折叠梁和振动质量 ,故驱动和检测间的耦合大大地减小。本文从理论上分析了折叠梁结构参数对振动模态频率的影响 ,并针对初步确定的结构尺寸 ,利用COVENTERWARE软件进行了静力学和动力学分析 ,对理论计算结果进行了验证     

Porous silicon for the development of capacitive microstructures

Macroporous silicon is developed in p-type substrates in order to extend the active surface area of the electrodes in a silicon integrated capacitive element. Some laboratory prototypes with a 3D architecture and Si/SiO₂/PolySi layers have been developed. The contribution of the surface enlargement to the final capacitance is analyzed by comparing it with a 2D planar reference capacitive device. By this method, a capacitance gain of 2400% has been obtained at low frequencies with a capacitance density of 180 nF/cm². Based on the physical microstructure, an equivalent electrical circuit of the porous capacitive element is proposed and its electrical behavior discussed.     

Uniformity of silicon microcrystallinity in large area RF capacitive reactors

In this work, a controlled, nonuniform RF power distribution is produced across a large area PECVD reactor. The effect of the RF power distribution on the crystallinity of silicon thin films deposited from silane‐hydrogen discharges is studied. Results show that, even with a strongly nonuniform RF distribution (70%), uniform crystallinity can still be achieved for films deposited at the limit between amorphous and microcrystalline silicon provided that the input silane concentration is sufficiently low (nominal concentration lower than ≈︂1˙2%). This work shows that to deposit silicon with a uniform microcrystallinity over large area using high silane concentration, the reactor design must guarantee a highly uniform power distribution. Copyright © 2008 John Wiley & Sons, Ltd.     

Solution growth of Indium-Doped silicon

Indium-doped silicon has been grown from indium-rich solutions using a gradient-transport solution growth process. The growth temperatures were varied from 950‡ to 1300‡C to determine the solubility limits of indium in silicon. The maximum indium concentration obtained was 1.6×10¹⁸/cm³ at a growth temperature of 1300‡ but indications are that the maximum solubility is 2. 5×10¹⁸/cm³. The growth process is described by one-dimensional diffusion limited transport and predicts growth rates in excess of lcm/day at 1300‡C. Infrared absorption measurements were used to monitor the indium, oxygen and carbon concentrations, in addition to the shallower .indium: X defect found in the crystals. The solution-grown crystals were found to have a lower concentration of this shallower defect than melt grown crystals of the same indium concentration. The oxygen and carbon concentrations increased with the increased growth temperatures suggesting a solubility limited value. The shallower indium: X defect also increased with growth temperature, but the concentration was significantly lower than typically found in melt-grown crystals. The peak optical cross-section for indium was also determined to be 5.3×10^-17cm² from these measurements. This work was sponsored in part by the Defense Advanced Research Projects Agency under Order No. 3211, monitored by NV & EOL under Contract No. DAAK70-77-C-0194.     

碳化硅基骨架炭的制备及其电容特性研究

在微波加热条件下,无机碳化物SiC与Cl2反应,通过去除碳化物的非碳原子来制备骨架炭(CDC),采用XRD、SEM、HRTEM等检测方法,对制备的骨架炭进行了表征,研究了其电容特性。结果表明:CDC具有较低的电阻率,较高的振实密度,质量比电容量为170F/g,体积比电容量为110F/cm3,是一种性能优良的双电层电容器的电极材料。     

Removal of impurities from metallurgical grade silicon by electron beam melting

Solar cells are currently fabricated from a variety of silicon-based materials.Now the major silicon material for solar cells is the scrap of electronic grade silicon(EG-Si).But in the current market it is difficult to secure a steady supply of this material.Therefore,alternative production processes are needed to increase the feedstock.In this paper,EBM is used to purify silicon.MG-Si particles after leaching with an initial purity of 99.88%in mass as starting materials were used.The final purity of the silicon disk obtained after EBM was above 99.995%in mass.This result demonstrates that EBM can effectively remove impurities from silicon.This paper mainly studies the impurity distribution in the silicon disk after EBM.     

Research on Removal of Impurities from Metallurgical Grade Silicon（MG-Si） by Electron Beam Melting（EBM）

Solar cells are currently fabricated from a variety of silicon-based materials.Now the major silicon material for solar cells is the scrap of electronic grade silicon(EG-Si).But in the current market it is difficult to secure a steady supply of this material.Therefore,alternative production processes are needed to increase the feedstock.In this paper,EBM is used to purify silicon.MG-Si particles after leaching with an initial purity of 99.88%in mass as starting materials were used.The final purity of the...