Study On Key Technologies Of Monolithic Triaxial Micro-accelerometer

Compared with traditional accelerometers, micro-machined ones have a variety of virtues due to their low cost, small size and light weight. The triaxial micro-accelerometers are key components of inertial navigation system and has a variety of applications in many fields such as weapons, navigation, safety, automation, etc. Therefore, developing high performance micro-machined accelerometer is of great importance.A novel micro-machined accelerometer is designed in this dissertation, which has no deep-aspect ratio structure and can be fabricated by wet etching. This dissertation focuses on the structure design, fabrication, read-out techniques, errors, noise and characterization of the triaxial micro-machined accelerometer. Subsequent research contents are included in this dissertation.1. The structure details of the micro-machined accelerometer is presented, and the design theory is also studied, which includes the relevant movement equations and the dynamic controllable model, etc.2. According to the structure details and present equipments, the fabrication progress of this triaxial micro-machined accelerometer is designed. Several samples are fabricated . Some key problems are studied and improved programs are presented.3. Based on the present detecting technologies, a capacitance read-out scheme is designed according to the configuration of the accelerometer's capacitors.4. A fabricated triaxial micro-machined accelerometer is characterized. The detection systems are designed, the mode and signal of accelerometer are tested. Errors caused by the structure dimension and cross-couplings, as well as the thermal-mechanical noise and primary circuit noise are analyzed. Some methods are presented to reduce the circuit noise.This work will provide a theoretic foundation for the future study and development of the micro-machined triaxial accelerometer.