Microelectromechanical resonator manufactured using CMOS-MEMS technique

The fabrication of a microelectromechanical resonator using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process and a post-process has been implemented. The resonator requires only one wet etching post-process. The suspended structures in the resonator consist of a membrane and four beams. The post-process utilizes an etchant to etch the sacrificial layer, and to release the suspended structures. Easy execution and low cost are the advantages of the post-process. The resonator comprises a driving part and a sensing part. The sensing part produces a change in capacitance when applying a driving voltage to the driving part in the resonator. A circuitry is used to convert the capacitance variation of the sensing part into the voltage output. Experimental results show that the resonant frequency of the resonator is about 39.5 MHz and the quality factor is 806.     

A novel dual-functional MEMS sensor integrating both pressure and temperature units

This paper proposes a novel miniature dual-functional sensor integrating both pressure and temperature sensitive units on a single chip.The device wafer of SOI is used as a pizeoresistive diaphragm which features excellent consistency in thickness.The conventional anisotropic wet etching has been abandoned,while ICP etching has been employed to etch out the reference cave to minimize the area of individual device in the way that the 57.4°slope has been eliminated.As a result,the average cost of the singl...     

新型集成压力与温度MEMS传感器

本文提出一种MEMS传感器,单片集成温度和气压的检测单元。该传感器采用SOI硅片的上层硅作为压阻薄膜,因此各管芯的薄膜厚度有良好的一致性。传统的背面体硅腐蚀方法未被采用,因为碱性溶液腐蚀体硅会在<111>面自停止,形成57.4°的斜坡,从而增大管芯面积,取而代之的是ICP深硅刻蚀。片上集成两个PN结,结区面积呈比例,可以实现温度检测功能。测试表明在-40-100℃之间都有良好的线性度,PN结的离子注入工艺与压阻注入工艺完全兼容,减少了工艺成本。     

Diaphragm design guidelines and an optical pressure sensor based on MEMS technique

The design guidelines for micro diaphragm-type pressure sensors have been established by characterization of the relationships among diaphragm thickness, side length, sensitivity, and resonant frequency. According to the study, the thickness need to be thin and the side length need to be small in order to get the sensitive diaphragm with high resonant frequency. A Fabry-Perot based pressure sensor has been designed based on the guidelines, fabricated and characterized. In principle, the sensor is made according to Fabry-Perot interference, which is placed on a micro-machined rectangular silicon membrane as a pressure-sensitive element. A fiber-optic readout scheme has been used to monitor sensor membrane deflection. The experimental results show that the sensor has a very high sensitivity of 28.6 mV/Pa, resolution of 2.8 Pa, and up to 91 kHz dynamic response.     

集成风速计片上系统的计算机模拟

将MEMS器件与CMOS电路集成在同一个芯片上具有体积小、噪声小、便于控制、易于大批量生产等优点 ,本文从风速计的工作场入手 ,运用了有限元、数据拟合、等效电路及SPICE宏单元的方法对片上系统进行模拟 ,从而直接模拟出信号状况 ,有利于片上处理电路和控制电路的匹配设计 ,提高了设计效率。文中给出了风速计流体场的有限元分析结果 ,并通过拟合的方法将输出的温度差输出到电路等效的热堆 ,信号和噪声经过片上集成的放大器输出到芯片外 ,有利于温度场、热敏感元件、放大电路的优化设计     

CMOS工艺兼容多晶硅压力敏感膜的设计与加工

在MEMS表面加工工艺中 ,多晶硅薄膜是微结构的重要组成部分。本文考虑加工工艺中残余应力的影响和多晶硅材料的强度范围 ,建立多晶硅膜的大变形模型 ,设计可用于压力传感器应用的多晶硅薄膜几何尺寸。采用有限元方法对多晶硅薄膜进行力学分析和设计验证 ,提出了CMOS工艺兼容的多晶硅压力敏感膜的加工方法 ,并且根据所设计的工艺进行了电容式压力传感器微结构的加工 ,加工结果说明了多晶硅薄膜设计的合理性和CMOS兼容工艺的可行性     

一种新型的CMOS集成湿度传感器

利用MEMS技术 ,对一种新型CMOS湿度传感器进行理论分析、模拟以及结果讨论。该湿度传感器采用标准CMOS工艺制造 ,采用梳状铝电极结构、梳状多晶硅加热结构 ,衬底接地 ,感湿介质采用聚酰亚胺 ,利用商业软件Coventor进行模拟绘制出敏感电容与相对湿度的曲线图。接口电路采用开关电容电路 ,输出可测电压信号 ,利用Microsim公司的Pspice模拟电路得到相对湿度与输出电压曲线关系     

真空微电子压力传感器阵列数据采集研究

阐述了真空微电子压力传感器阵列的工作原理和工作波形。设计了一种供真空微电子压力传感器阵列器件使用的 12位A/D数据采集系统。系统采用微机为主控单元 ,地址发生和时序控制部分采用可编程逻辑器件 (CPLD)实现 ,提高了设计的灵活性 ,简化了电路板设计。利用该采集系统对压力传感器阵列进行了数据采集 ,最后给出了实验结果     

一种半岛型结构谐振梁压力传感器

提出了一种新型结构压力传感器 ,器件由上下两硅片键合而成 ,上硅片制作半岛型结构氮化硅谐振梁 ,下硅片制作矩形压力膜。应用有限元软件对器件结构及灵敏度进行了计算机模拟分析 ,器件利用MEMS技术研制并采用电热激励压阻拾振方式进行了测试。实验及理论模拟分析结果证实新型结构可以大大提高压力传感器灵敏度     

CMOS电容式湿度传感器特性研究

提出了一种CMOS电容式湿度传感器特性研究方案.研究所用的微电容湿度传感器由标准CMOS工艺结合MEMS 后处理技术加工而成.为了测试湿度传感器的响应时间,设计了一种响应时间测试装置.测试结果表明,该电容式湿度传感 器在相对湿度25％～95％的范围内具有较好的线性度;其回滞在75％RH时达到最大,为2％ RH;该传感器...     

一种新型的CMOS集成湿度传感器

利用MEMS技术，对一种新型CMOS湿度传感器进行理论分析、模拟以及结果讨论。该湿度传感器采用标准CMOS工艺制造，采用梳状铝电极结构、梳状多晶硅加热结构，衬底接地，感湿介质采用聚酰亚胺，利用商业软件Coventor进行模拟绘制出敏感电容与相对湿度的曲线图。接口电路采用开关电容电路，输出可测电压信号，利用Microsim公司的Pspice模拟电路得到相对湿度与输出电压曲线关系。     

一种适用于传感器接口电路中电容型SAR结构ADC的修调技术

本文提出了一种针对电容型逐次逼近型模数转换器（ADC）的修调技术及实现算法,采用了该技术的ADC可作为传感器和微控制器之间的接口电路使用。其特点在于这种修调后的电路可以在不需要单独的校正周期,也不需要附加复杂的校正功能,只需要通过对电容阵列的微调,就可以达到12-bit的分辨率。这种技术具有功耗和面积的优势,适合用于对功耗和成本较为敏感的电池供电系统,例如传感器网络结点。本文在0.5μm 2P3M CMOS工艺下设计了一个12bit分辨率的ADC原型电路,在2-5V电源电压下,200KHz采样速度下,其功耗仅为300μA。     

Micro packaged MEMS pressure sensor for intracranial pressure measurement

This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm². It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm². In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm². Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10^-2 mV/kPa.     

基于MEMS技术的微型电场传感器设计与仿真

报道了一种新型的基于MEMS技术的微型电场传感器。该传感器采用半导体微加工工艺制备 ,具有体积小、重量轻、功耗低等优点。阐述了传感器的工作原理 ,描述了设计方案 ,介绍了计算机模拟仿真结果     

高灵敏度光纤光栅静水压力传感研究

分析了光纤布拉格光栅的压力敏感及增敏原理,设计了一种适于高分辨率静水压力测量的封装结构,实验结果表明,该光纤光栅压力传感器压力响应灵敏度为9.03×10-3 MPa-1,比未封装的裸光纤光栅增敏2946倍,在长沙白鹭湖进行的基于静水压力的水深测量表明,该传感器的深度分辨能力优于5 cm,并有较好的线性和重复性,满足基于静水压力的拖曳缆深度测量应用需求.     

基于FET结构的Pt-LaF_3混合膜溶解氧传感器

研制了一种基于 FET结构的 Pt- L a F3混合膜全固态溶解氧传感器 .对 Pt- L a F3敏感膜的敏感机制以及传感器的器件结构和响应特性进行了分析 ,并实际测试了器件特性 ,给出了在不同工作点和不同温度条件下器件的输出电压对溶解氧浓度变化的响应曲线     

硅电容压力传感器敏感器件的研究

研制的硅电容压力传感器芯体采用微机械加工技术,加工精度高,易于批量化生产。结构上采用对称的差动电容形式,并将其封装在专用基座中,适用于中、微压力的高精度测量,可用于目前通用压力传感器的升级产品。     

Temperature characteristics research of SOI pressure sensor based on asymmetric base region transistor

Based on the asymmetric base region transistor, a pressure sensor with temperature compensation circuit is proposed in this paper. The pressure sensitive structure of the proposed sensor is constructed by a C-type silicon cup and a Wheatstone bridge with four piezoresistors (R₁, R₂, R₃ and R₄) locating on the edge of a square silicon membrane. The chip was designed and fabricated on a silicon on insulator (SOI) wafer by micro electromechanical system (MEMS) technology and bipolar transistor process. When the supply voltage is 5.0 V, the corresponding temperature coefficient of the sensitivity (TCS) for the sensor before and after temperature compensation are -1862 and -1067 ppm/℃, respectively. Through varying the ratio of the base region resistances r₁ and r₂, the TCS for the sensor with the compensation circuit is -127 ppm/℃. It is possible to use this compensation circuit to improve the temperature characteristics of the pressure sensor.     

探空集成传感器设计

微型化、集成化可以使得传感系统减少体积、重量 ,降低成本 ,提高系统的可靠性 ,具有重要的科学意义。本文设计了一个用于测量大气湿度、温度和气压检测微型集成传感器。考虑到MEMS加工工艺兼容性 ,分别采用空气导热检测法、铂电阻法和电容法对湿度、温度、压力进行检测 ,并且进行了理论计算 ,设计了加工工艺步骤 ,制作出雏形器件     

压阻式压力传感器信号噪声比改进研究

通过介绍压阻式压力传感器工作原理,分析噪声的主要起源,提出了针对不同噪声源(电噪声和外界电荷引起的非本征噪声)的解决措施,为将来针对高SNR的压力传感器设计提供参考依据。