Polysilicon strain-gauge transducers

Strain-gauge transducers with polysilicon resistors can be used successfully in various sensors. They have some advantages in comparison to monocrystalline silicon strain-gauge transducers. However, not enough information is available for the qualitative design of such transducers. The theoretical principles of the temperature dependence of the output signal for a constant supply voltage and constant supply current are described. A polysilicon strain-gauge transducer with a square diaphragm fabricated on the discussed principles is reported. It has an operating temperature range of −190- +300 °C, and weak temperature dependence of the output signal.     

Polysilicon nanofilm pressure sensor

Utilizing 80 nm polysilicon nanofilm as piezoresistors, a pressure sensor with high performance is developed. The complete fabrication process is described. The pressure properties of the sensor were measured at the temperature from 0 to 200 °C. For 0.6 MPa full scale pressure, the sensitivity is 23.00 mV/V/MPa at 0 °C and 18.27 mV/V/MPa at 200 °C, the temperature coefficient of sensitivity (TCS) is about −0.098%/ °C without any compensation. The temperature coefficient of offset (TCO) is about −0.017%/ °C. Because of the good piezoresistive and temperature characteristics of polysilicon nanofilm, the pressure sensor demonstrates a better performance.     

Static Friction in Polysilicon Surface Micromachines

Surface micromachines of polycrystalline silicon were used to investigate the dependence of static friction in microelectromechanical systems on the external load, apparent contact area, and environmental conditions. An analytical model of the micromachine at the inception of sliding was used to determine the normal load consisting of the restoring and levitation forces exerted by the micromachine's comb-drive actuators. The apparent shear strength at the contact interface(s) exhibited a nonlinear dependence on the apparent contact pressure. Relatively higher static coefficient of friction and interfacial shear strength were obtained in room air than vacuum ambient. The static coefficient of friction was found to depend on the normal load, apparent contact area, and ambient conditions (i.e., relative humidity). Electrical contact resistance measurements indicated that sliding in room air promoted thickening of the native oxide film at asperity contacts. The experimental evidence suggests that modification of the surface topography occurred at the asperity level. However, these submicroscopic changes in the surface topography did not affect the overall static friction behavior, for the test cycles simulated in the friction experiments.$hfillhbox[1225]$     

Polysilicon micro beams buckling with temperature-dependent properties

The suspended electrothermal polysilicon micro beams generate displacements and forces by thermal buckling effects. In the previous electro-thermal and thermo-elastic models of suspended polysilicon micro beams, the thermo-mechanical properties of polysilicon have been considered constant over a wide rang of temperature (20–900°C). In reality, the thermo-mechanical properties of polysilicon depend on temperature and change significantly at high temperatures. This paper describes the development and validation of theoretical and Finite element model (FEM) including the temperature dependencies of polysilicon properties such as thermal expansion coefficient and Young’s modulus. In the theoretical models, two parts of elastic deflection model and thermal elastic model of micro beams buckling have been established and simulated. Also, temperature dependent buckling of polysilicon micro beam under high temperature has been modeled by Finite element analysis (FEA). Analytical results and numerical results using FEA are compared with experimental data available in literature. Their reasonable agreement validates analytical model and FEM. This validation indicates the importance of including temperature dependencies of polysilicon thermo-mechanical properties such as Coefficient of thermal expansion (CTE) in the previous models.     

多晶硅微机械薄膜形成技术

介绍了多晶硅微机械薄膜的制备工艺,叙述了它的基本结构和工艺的研究,并给出了试验结果。     

等离子刻蚀多晶硅问题解析

多晶硅在MOS电路中占有极其重要的位置,掺杂后的多晶硅往往是用做栅极的导电材料。而腐蚀后的掺杂多晶硅的线宽决定了有源器件的栅长,而栅长确定了沟道长度并定义出了源漏电极的边界。湿法腐蚀多晶因其侧腐量大而不能使用,必须应用干法刻蚀,这里对多晶硅在干法刻蚀方面的一些问题进行了简要的分析及解决。     

Wear of Polysilicon Surface Micromachines Operated in High Vacuum

The evolution of wear at sidewall surfaces of polysilicon microelectromechanical systems was investigated in high vacuum under controlled normal load and sliding speed conditions. The static adhesion force was used as an indicator of the changes in wear characteristics occurring during oscillatory sliding contact. Measurements of the static adhesion force as a function of sliding cycles and scanning electron microscopy observations of micromachines from the same batch process subjected to nominally identical testing conditions revealed two distinctly different tribological patterns, namely, low-adhesion/high-wear behavior and high-adhesion/low-wear behavior. The static adhesion force and wear behavior were found to be in direct correlation with the micromachine operational lifetime. Transmission electron microscopy, selected area diffraction, and energy dispersive X-ray spectroscopy yielded insight into the origin, microstructure, and composition of wear debris and agglomerates adhered onto the sliding surfaces. Results demonstrate a strong dependence of micromachine operational life on the removal of the native oxide film and the organic monolayer coating as well as the formation of agglomerates consisting of organic coating material and wear debris.     

PCS7自动控制系统在多晶硅工厂的应用

介绍西门子公司的PCS7工控软件在多晶硅工厂的应用实例,包括软件功能、工艺流程等.     

多晶硅衬底结晶度检测的自适应算法研究

多晶硅衬底图像具有对比度低的特点,在检测硅片结晶度时缺少成熟可用的算法,提出一种新的图像处理算法,基本完成多晶硅晶畴自动检测的算法框架.将图像分块后对子块进行晶畴边缘提取,然后拼接所有边缘,从而提取出整幅图像的晶畴轮廓.针对边缘拼接,重点研究自适应膨胀算法和蚁群算法,并提出基于梯度的改进算法.实验证明算法运算简单,拼接效果好.该技术路线经进一步优化将可实现多晶硅衬底的结晶度自动检测.     

多晶硅还原炉电源系统的一体化解决方案

多晶硅是生产环保新能源--太阳能光伏电池的最基础的材料。本文首先概述了多晶硅生产工艺及其实现方法,然后着重描述了多晶硅还原炉电源系统的一体化解决方案以及针对用户的配套方案。     

台达机电产品在数控多晶硅切断机床中的应用

本文主要介绍台达机电产品在数控多晶硅切断机床上的整合应用。该控制系统操作界面友好简单,结合台达HMI、PLC、和伺服及变频器等自动化产品,实现了设备的技术升级与高效节能,体现出台达自动化产品较高的性价比。运行实践证明,台达产品稳定可靠,控制效率高,值得业界同行借鉴和推广。     

基于阈值分割的多晶硅晶畴检测方法

晶畴的区域分割提取是利用数字图像实现多晶硅结晶度检测中的一项关键技术．其中阈值的自动选择是实现自动化检测结晶度的核心。针对多晶硅图像的特点．充分利用图像的直方图信息．通过结合双峰法与波形对称性分析首先得到阈值数以及阈值的初步取值,然后利用最大类间方差法精确确定闽值．再进行硅片图像分割。实验证明．这种方法结合了双峰法和最大类间方差法的优点．在对多晶硅图像进行晶畴分割提取时能够获得优良的检测效果并明显提高算法的效率．为实现工业在线自动检测奠定坚实的基础。     

基于AlN绝缘的多晶硅高温压力传感器设计

探讨了一种多晶硅高温压力传感器的设计方法,采用AlN作硅衬底和多晶硅力敏电阻条之间的电绝缘层,由于无p-n结,力敏电阻无反向漏电,使制作的压力传感器特性好.利用多晶硅材料在高温条件下能够表现出良好的压阻特性,考虑其纵横向压阻效应的不同,作了理论分析,在此基础上制作力敏电阻条.利用有限元分析方法,借助MARC软件,模拟了传感器承压弹性膜的应力场分布.确定了多晶硅力敏电阻条的位置和排列方式.并且施加10kPa压力时,模拟了不同膜厚t与对应的最大应力o11的曲线;模拟了11方向主应力COMP11边缘中点应力为一特定值时所需压力尸N与膜厚t的关系曲线.     

基于阈值分割的多晶硅晶畴检测方法

0引言晶畴的区域分割提取是利用数字图像实现多晶硅结晶度检测中的一项关键技术,其中阈值的自动选择是实现自动化检测结晶度的核心。针对多晶硅图像的特点,充分利用图像的直方图信息,通过结合双峰法与波形对称性分析首先得到阈值数以及阈值的初步取值,然后利用最大类间方差法精确确定阈值,再进行硅片图像分割。实验证明,这种方法结合了双峰法和最大类间方差法的优点,在对多晶硅图像进行晶畴分割提取时能够获得优良的检测效果并明显提高算法的效率,为实现工业在线自动检测奠定坚实的基础。     

基于AIN绝缘的多晶硅高温压力传感器设计

探讨了一种多晶硅高温压力传感器的设计方法,采用AIN作硅衬底和多晶硅力敏电阻条之间的电绝缘层,由于无p-n结,力敏电阻无反向漏电,使制作的压力传感器特性好。利用多晶硅材料在高温条件下能够表现出良好的压阻特性,考虑其纵横向压阻效应的不同,作了理论分析,在此基础上制作力敏电阻条。利用有限元分析方法,借助MARC软件,模拟了传感器承压弹性膜的应力场分布,确定了多晶硅力敏电阻条的位置和排列方式。并且施加10kPa压力日寸,模拟了不同膜厚t与对应的最大应力σ11的曲线;模拟了11方向主应力COMP11边缘中点应力为一特定值时所需压力PN与膜厚t的关系曲线。     

故障自动防护微机械角速度传感器

微机械角速度传感器是目前市场上能够进行批量生产的最复杂的传感器之一。它由在真空中做复杂运动的惯性质量块和驱动该设备、分析其响应的多种复杂电路组成,并集中于一个在极狭小的空间内。本文介绍了由奥地利SensorDynamics公司成功研制的一种MEMS角速率传感器,可以满足现代应用的全部要求,尤其是汽车工业所要求的小尺寸、坚固的机械结构、长期稳定性、不受限制的故障自动防护性和AEC-Q100认证。