八梁硅微加速度传感器横向灵敏度的研究

一般的压阻式硅微加速度传感器结构多采用悬臂梁加质量块的形式,这种结构的传感器有很高的灵敏度,但它会产生很高的横向效应.文中介绍一种八梁结构的三轴加速度传感器,通过用ANSYS有限元分析软件仿真计算,说明该结构的加速度传感器具有很小的横向效应.     

基于三梁结构的电热驱动谐振式微加速度传感器研究

为了提高电热激励/压阻拾振谐振式微加速度传感器的品质因数和消除交叉灵敏度,提出一种基于三梁结构的新设计.依据有限元模拟得到的固有振型来选择三梁结构参数,以减少能量耗散,提高品质因数.分析本设计消除交叉灵敏度的机制和独特的三梁结构的激振方式并对其进行有限元模拟.模拟结果证实这种谐振式微加速度传感器的灵敏度高于1000 Hz/g.     

谐振式微加速度传感器的有限元分析

有限元分析用来评估一种新颖的谐振微加速度传感器,仔细分析新结构的几个主要振动模态,优化结构参数,证实这种硅基谐振式微加速度传感器的灵敏度高于1 000 Hz/gn.而且在有限元分析的基础上对实际制造的非完全匹配的双端固定音叉的特点和对于测量的不良影响进行分析.     

压阻式硅微型加速度传感器的研制

利用微加工技术制作了压阻式硅微型加速度传感器,对制作的加速度传感器样品进行了动态测试,单臂梁结构的加速度传感器的灵敏度为1μV/gn,双臂梁结构加速度传感器的灵敏度为1.6μV/gn,结果与理论设计值基本吻合。     

一种新颖的微杆杠结构的理论建模及其在谐振式微加速度传感器中的应用

为了提高谐振式微加速度传感器的灵敏度,提出一种新颖的微杠杆结构.分析该结构的工作原理,推导该结构的理论模型,得到这种微杆杠放大倍数的解析表达式.在这个理论模型的基础上,为了进一步提高微杆杠的放大倍数,对其参数进行优化,分析微杆杠结构中各参数对于放大倍数的影响,优化后该结构的放大倍数高达200.基于这种微杠杆结构设计两种分别为静电驱动/电容检测和电热驱动/压阻拾振的谐振式微加速度传感器,分别介绍这两种传感器的工作原理及其特点,并对这两种结构进行有限元模拟.模拟结果证实这两种微加速度传感器的灵敏度均高于1 000 Hz/gn,进而验证这种新提出的微杠杆结构的有效性.     

一种电容式微加速度计的结构设计和工艺仿真

微硅电容式加速度计是目前微硅加速度传感器发展的主流,本文在硅-玻璃阳极键合工艺同深槽刻蚀工艺相结合的加工技术基础之上设计了一种电容式微加速度计,该结构将两种改变平行板电容量的方式有效的结合在一起,提高了结构的灵敏度并具有较好的线性度.最后,对所设计的结构进行了工艺仿真,通过虚拟工艺仿真结果与设计进行比较,论证了结构的基本可行性.     

并联式六维加速度传感器灵敏度特性

基于一种新提出的并联式六维加速度传感器结构,从系统的正向动力学方程出发,构建了其灵敏度的数学模型,推导出灵敏度与结构参数间的映射关系.基于ADAMS软件对传感器进行参数化建模,并以灵敏度为优化目标,将仿真数值与理论计算的结果进行对比,验证了数学模型的正确性.结果表明:线加速度灵敏度主要受质量块的质量影响,角加速度灵敏度同时受质量块质量和边长影响,而外壳尺寸与灵敏度无关,且在空间三个正交方向的线加速度灵敏度和角加速度灵敏度均满足各向同性.     

一种大量程加速度传感器的性能测试

设计的一种大量程加速度传感器敏感单元采用一对双端固支结构,实现硅平面内加速度的测量,通过马歇特锤冲击测试试验和Hopkinson杆激光干涉冲击测试,分别标定了传感器的灵敏度和动态响应,试验结果表明:测试传感器的灵敏度为0.126μV/gn,工作频带为21.46 kHz,工作频带的动态重复性为3.9%,能够满足实际的测试需求,为实现单芯片集成三独立质量块结构的三轴加速度传感器提供了参考依据。     

利用阵列传感系统降低硅微机械 加速度传感器的横向灵敏度

为消除带质量块的压阻式硅微加速度传感器的横向灵敏度,曾采取许多办法,但收效甚微,为此本文提出利用传感器阵列降低硅微加速度传感器的横向灵敏度的方法.以     

一种压阻式三轴加速度传感器的设计

介绍了一种基于SOI的硅压阻式三轴加速度传感器的设计和制备.该三轴加速度传感器采用四个相互垂直的悬臂梁支撑中间质量块的结构.加速度传感器通过利用合理布置的压敏电阻构成的惠斯通电桥测量三个方向的加速度.对加速度传感器结构进行了理论分析和有限元仿真优化,确定加速度传感器的结构尺寸,并详细论述了三轴加速度传感器的制备工艺步骤和测试结果.     

一种新结构硅微机械压阻加速度计

设计、制造并测试了一种新结构硅微机械压阻加速度计.器件结构是悬臂梁-质量块结构的一种变形.比较硬的主悬臂梁提供了一定的机械强度,并且提供了高谐振频率.微梁很细,检测时微梁沿轴向直拉直压.力敏电阻就扩散在微梁上,质量块很小的挠动就能在微梁上产生很大的应力,输出很大的信号.5 V条件下,灵敏度为14.80 mV/g,谐振频率为994 Hz,分别是传统结构压阻加速度计的2.487倍和2.485倍.加速度计用普通的N型硅片制造,为了刻蚀高深宽比的结构,使用了深反应离子刻蚀(DRIE)工艺.     

Fabrication of a MEMS capacitive accelerometer with symmetrical double-sided serpentine beam-mass structure

This paper presents a symmetrical double-sided serpentine beam-mass structure design with a convenient and precise process of manufacturing MEMS accelerometers. The symmetrical double-sided serpentine beam-mass structure is fabricated from a single double-device-layer SOI wafer, which has identical buried oxides and device layers on both sides of a thick handle layer. The fabrication process produced proof mass with though wafer thickness (860 μm) to enable formation of a larger proof mass. Two layers of single crystal silicon serpentine beams with highly controllable dimension suspend the proof mass from both sides. A sandwich differential capacitive accelerometer based on symmetrical double-sided serpentine beams-mass structure is fabricated by three layer silicon/silicon wafer direct bonding. The resonance frequency of the accelerometer is measured in open loop system by a network analyzer. The quality factor and the resonant frequency are 14 and 724 Hz, respectively. The differential capacitance sensitivity of the fabricated accelerometer is 15 pF/g. The sensitivity of the device with close loop interface circuit is 2 V/g, and the nonlinearity is 0.6 % over the range of 0–1 g. The measured input referred noise floor of accelerometer with interface circuit is 2 μg/√Hz (0–250 Hz).     

A MEMS sandwich differential capacitive silicon-on-insulator accelerometer

A differential capacitive accelerometer with simple process is designed, simulated, and fabricated. To achieve a precision structure dimension with fewer processing steps, the silicon device layer transfer technology is being used to built a sandwich accelerometer based on a silicon-on-insulator (SOI) wafer, which was assembled by glass-si-glass multilayer anodic bonding. Deep reactive ion etching is being used to define symmetric beams and large mass block of equal thickness together in SOI device layer (up to 100 μm) in a single step to avoid alignment error in double side process. An actual accelerometer which is designed for 50 g measure range is fabricated with six lithography steps. Measurement results show 0.1166 V/g sensitivity and 0.022 % nonlinearity error in ±1 g gravity static response test. The accelerometer also provides a power spectrum less than 10.49 μVrms/Hz^1/2 (89.97 μg/Hz^1/2) in a non-isolated laboratory environment with a capacitive interface circuit.     

一种电容式微机械加速度计的设计

介绍了一种新型基于滑膜阻尼的电容式微机械加速度计.该加速度计根据差分电容极板间正对面积的改变来检测加速度大小,保证了输出电压与加速度之间的线性度.对加速度计进行了结构设计和分析.给出了加速度计的制作工艺流程,研究了解决深反应离子刻蚀过程中的过刻蚀现象的方法.初步测试结果表明,该加速度计的灵敏度比较理想,谐振频率与理论计算相吻合.     

不等基频硅微谐振式加速度计

分析了硅微谐振式加速度计的两个谐振器在谐振频率相交点附近区域产生耦合的原因,设计了一种新型的不等基频硅微谐振式加速度计,并对其进行了有限元仿真.该加速度计由质量块、放大惯性力的杠杆机构以及一对尺寸不同的谐振器组成.采用DDSOG工艺加工.利用ANSYS有限元软件进行仿真,结果表明加速度计上谐振器的谐振基频为124 67...     

三梁-质量块敏感结构高性能压阻式碰撞加速度计

研究了一种主要应用于碰撞测试领域的硅微机械高性能压阻式加速度计,量程范围为2 000 gn.为满足技术性能要求,加速度计采用一种三梁-质量块结合梳齿阻尼器的新颖结构,从而可以同时具有高灵敏度及高动态特性(包括高谐振频率及精确阻尼控制).这种加速度计采用n型(100)普通硅片制作,主要工艺过程包括双面ICP深刻蚀和压阻集成工艺.振动台测试结果表明,加速度计的灵敏度为0.11 mV/gn/5 V,谐振频率为31 kHz,灵敏度±5%变化下平坦带宽大于5 kHz.采用落杆测试法测试了加速度计的冲击响应及0～2 000 gn满量程范围内的非线性度.封装后的加速度计承受15 000 gn的冲击测试后没有受到损坏.     

A novel out-of-plane MEMS tunneling accelerometer

A novel out-of-plane MEMS tunneling accelerometer is designed, fabricated and characterized. ICP process, which can generate large proof mass, is used for the first time to fabricate an out-of-plane tunneling accelerometer. To reduce the high Hooke's constant in out-of-plane direction of the ICP etching structure, the beams and the proof mass are dry-etched by double mask ICP process, which reduce the Hooke's constant, thereby enhance the sensitivity of the device. The tunneling current of open loop is tested in the air by HP4145B semiconductor analyzer, which verifies the presence of tunneling current and shows the needed driving voltage. The close-loop test shows sensitivity of 811 mV/g for feedback voltage (the sensitivity of actuate voltage is about 200 mV/g) and nonlinearity of 1% in the measurement range of 0 to +1 g. The spectrum measurement is performed in general environment and the resolution of the device is 0.5 mg/rtHz (1.25–100 Hz), which shows better low frequency property.     

Design and fabrication of submicrometer, single crystal Siaccelerometer

A lateral accelerometer has been designed, simulated, and fabricated using a 3-mask high-aspect ratio technology. Electron beam lithography and high-density plasma etching in an inductively coupled plasma source enabled aspect ratios >30 to be achieved. This makes possible beams with very small spring constants. Combining the ability to measure very small displacement of a proof mass due to narrow capacitive gaps between comb fingers, a highly sensitive accelerometer can be obtained. The fabricated accelerometer with 1 μm beams and 0.2 μm comb gaps had a spring constant of 0.127 N/m, which is close to the calculated values of 0.146 N/m. Based on the capacitance measurements, the accelerometer sensitivity is calculated to be 6.3 fF/g. Reducing the beam width to 0.4 μm lowered the spring constant to 0.03 N/m, and an improved equivalent sensitivity of 79.2 fF/g is calculated. The minimum detectable acceleration is on the order of a few microgravity over a range of hundreds of gravities     

基于SOI的硅微谐振式压力传感器芯片制作

采用SOI硅片,基于MEMS技术,设计并加工了一种新型三明治结构的硅微谐振式压力传感器,根据传感器敏感单元的结构设计,制定了相应的制备工艺步骤,并且针对湿法深刻蚀过程中谐振子的刻蚀保护等问题,提出了一种基于氮化硅、氧化硅和氮化硅三层薄膜的保护工艺,实验表明,在采用三层薄膜保护工艺下进行湿法刻蚀10 h后,谐振子被完全释放,三层薄膜保护工艺对要求采用湿法刻蚀镂空释放可动结构具有较高的实用价值。最后对加工完成的谐振式压力传感器进行了初步的性能测试,结果表明,在标准大气压力下谐振子的固有频率为9.932 kHz,品质因数为34。     

Single- and Triaxis Piezoelectric-Bimorph Accelerometers

This paper describes the novel single- and triaxis piezoelectric-bimorph accelerometers that are built on parylene beams with ZnO films. The unamplified sensitivity and the minimum detectable signal of the fabricated single-axis accelerometer are measured to be 7.0 mV/g and 0.01 g, respectively, over a frequency range from 60 Hz to subhertz. The linearity of the sensitivity as a function of acceleration is measured to be 0.9% in the full scale. A highly symmetric quad-beam bimorph structure with a single proof mass is used for triaxis acceleration sensing and is demonstrated to produce high sensitivity, low cross-axial sensitivity, and good linearity, all in a compact size. The unamplified sensitivities of the X-, Y-, and Z-axis electrodes (of the triaxis accelerometer) in response to the accelerations in X-, Y-, and Z-axes are 0.93, 1.13, and 0.88 mV/g, respectively. The worst-case minimum detectable signal of the triaxis accelerometer is measured to be 0.04 g over a bandwidth ranging from subhertz to 100 Hz. The cross-axial sensitivity among the X-, Y-, and Z-axis electrodes is less than 15% in the triaxis accelerometer. The theoretical analyses of the charge sensitivities and resonant frequencies along with the effects of residual stress on the charge sensitivities are presented for both the single- and triaxis accelerometers.