Integrated Inertia Measurement Systems

加速度计和角速率传感器（陀螺仪）是运动控制不可或缺的。本课题的目的是研制具有不同轴向加速度传感器和角速率传感器的惯性测量系统，主要研究成果如下：1.基础技术的发展：已经开发出检测screwmass位移的电容传感器。该传感器需要薄的电容器间隙，这可以通过最小化阳极键合的玻璃-硅结构的结构变形来实现。为了控制腔体压力，采用一种新的封装方法控制腔体压力，研究了硅的深反应离子刻蚀和选择性XeF_2刻蚀。我们的谐振式角速率传感器采用了前者的深反应离子刻蚀技术。将这两种刻蚀方法结合起来，可以发展出在晶片厚度的中间部分制作梁的TBBMM方法。提出了一种新的不需要外加偏压的电化学腐蚀停止方法，这些新的腐蚀技术为传感器的设计提供了自由度.惯性测量系统研制了多轴加速度和角速率精密测量传感器.硅谐振式角速率传感器研制了硅音叉谐振式角速率传感器。采用电磁、静电、压电激励和电容检测。这些传感器是在真空腔中具有谐振器的封装结构。研究了谐振频率的电调谐以提高灵敏度.静电悬浮陀螺仪的基础研究研究对静电悬浮硅盘微机械陀螺仪进行了研究。对悬浮体进行了模拟、制作和初步实验。

Accelerometers and angular rate sensors (gyroscopes) are indispensable for motion control. The purpose of this project is to develop integrated inertia measurement sytems which have acceleration sensors and angular rate sensors for diferent axs in it. Following achievements have been obtained.1. Development of basic technologies :Capacitive sensors to detect the displacement of the scismic mass have been developed. This sensor requires thin capacitor gap, which can be attained by minimizing structural distortion of the anodically bonded glass-silicon structure. For dumping control the cavity pressure was controlled by a new packaging method.Silicon etching as deep reactive ion etching (RIE) and selective XeF_2 etching were studied. The former deep RIE was applied for our resonant angular rate sensor. By combining these two etching methods TBBMM method by which beams can be fabricated in the middle part of the wafer thickness could be deeloped. A new electrochemical etch-stop methods which need not external bias voltage was also developed.These new etching technologies gives Freedoms for sensor design.2. Inertia measurement systemsSenors for simultanious measurements of multi-axs accelerations and angular rates have been developed.3. Silicon resonant angular rate sensorResonant angular rate sensors which use silicon tuning forks were fabricated. Electromagnetic, electrostatic and piezoelectric excitations and capacitive detection were emloyed. These sensors are packaged structures which have resonators in vacuum cavities. Electrical tuning of the resonant frequency was studied for improving the sensitivity.4. Basic research for electrostatically levitating rotatinal gyroscopeMicromachined rotational gyroscope using elecrostatically levitating silicon disc has been studied. Simulation, fabrication and priliminary experiments of levitation were made.