【作者】 赵晓霞；

【导师】 梁庭；

【作者基本信息】 中北大学 ， 测试计量技术及仪器， 2013， 硕士

【摘要】 近年来，由于GaN优异的材料特性，例如机械、热、化学稳定性以及生物兼容性等，使基于GaN的微机电系统（MEMS）得到了学术界的广泛关注。AlGaN/GaN异质结构材料体系具有很大的带阶差和很高的熔点，使其在高温、高频、大功率微波电子器件中的应用具有很大潜力。目前在微惯性测量组合中的器件广泛采用悬臂梁结构与场效应晶体管的集成结构来实现惯性信号的测量。而高电子迁移率晶体管（High Electron Mobility Transistor）作为场效应晶体管中的一种，也开始广泛应用于通信、电子等领域，它具有大功率、低噪声、高频、高速等特点。对利用力电耦合原理制备出的AlGaN/GaN基HEMT微加速度计结构，进行静态特性检测，分析并给出加速度计的静态特性参数，根据得到的参数对结构进行优化设计，为得到更高灵敏度、线性度和更大量程的加速度计奠定了基础。本文首先应用AlGaN/GaN HEMT微悬臂梁结构器件的力电耦合原理，设计出对AlGaN/GaN HEMT微加速度计的静态特性进行测试的合理实验方案。通过对AlGaN/GaN HEMT加速度计在静态0¹0g的惯性测试，得出该加速度计的灵敏度为0.12mA/g，表明结构灵敏度较小；其次，通过对微加速度计工艺过程的分析，总结了微结构残余应力的产生原因，并利用激光拉曼应力测试仪对微结构的残余应力进行了测试分析，得出残余应力对器件与结构性能产生的影响，为下一步改进结构奠定基础；第三，在此基础上，重新优化了加速度计结构，根据加速度传感器的敏感元件结构尺寸对灵敏度、线性度和频响范围等性能的影响，结合有限元静力分析和模态分析得出了结构的具体参数，并与原结构进行比较。经过计算分析，证明经过优化后的结构灵敏度由4.13×10^-3um/g提高到3.07×10^-2um/g，增大了一个数量级。能够承受350g的纵向冲击和500g的横向冲击，频率响应范围在0³000Hz之间，理论上满足了高灵敏度微加速度计的基本要求。但是加速度计在频响范围方面还有所欠缺。更多还原

【Abstract】 In recent years, due to the characteristics of the material excellent in GaN, forexample, mechanical, thermal, chemical stability and biological compatibility,GaN-based micro-electromechanical systems （MEMS） has been widespread concernin academic circles. AlGaN/GaN heterostructure material system having a large bandlevel difference and a high melting point, so that it has a great potential for applicationin high-temperature, high-frequency, high-power microwave electronic devices. Atpresent, the devices are widely used in the micro inertial measurement unit cantileverstructure with field-effect transistor integrated structure to achieve inertialmeasurement signal. High electron mobility transistors （High Electron MobilityTransistor） as a field-effect transistor, have been widely used in communications,electronics and other fields, it has the characteristics of high-power, low-noise,high-frequency, high-speed. The use of electromechanical coupling principle preparedAlGaN/GaN-based HEMT micro-accelerometer structure, static characteristics ofdetection, analysis, given the parameters of the static characteristics of theaccelerometer, according to the parameters to optimize the design of the structure, inorder to get a higher sensitivity, linearity, and laid the foundation for a greater range ofaccelerometers.Firstly, application of AlGaN/GaN HEMT micro-cantilever structure of thedevice electromechanical coupling principle, reasonable experimental programdesigned to test the static characteristics of AlGaN/GaN HEMT micro-accelerometer.On the AlGaN/GaN HEMT acceleration of0to10g of the static friction test, thesensitivity of the accelerometer obtained0.12mA/g, indicating that the structuresensitivity smaller; Second, the analysis of the process of micro-accelerometer,summed up the causes of the micro-structure of residual stress, and the use of the Raman stress tester on the residual stress of the micro-structure were tested, drawresidual stress on the device structure and propertiesthe impact of the foundation forthe next step to improve the structure; Third, on this basis, re-optimize the structure ofthe accelerometer sensitive components of the acceleration sensor dimensions on theperformance of the sensitivity, linearity and frequency response range, combined withthe finite element static analysis and modal analyzesthe specific parameters of thestructure, and compared with the original structure. After the calculation and analysis,that the optimized structure sensitivity from4.13×10^-3um/g to improve to3.07×10^-2um/g, increases an order of magnitude. Able to withstand the longitudinalimpact of350g and500g of the lateral impact, the frequency response range between0³000Hz, in theory, meet the basic requirements of the high sensitivity of themicro-accelerometer. Accelerometer in the Frequency Range lacking.更多还原