Joint study on high performance resonant sensors

在这项研究中，开发了新的微加工工艺和谐振传感器的制作。总结如下。1.为了制作高灵敏度的微谐振器，建立了一种适用于扫描探针显微镜（SPM）的对置电极窄间隙薄悬臂梁的制作工艺。硅悬臂的厚度和悬臂与玻璃衬底之间的差距小于1 μ m。提出了一种新的干燥方法，避免了液体表面张力引起的粘滞现象.为了实现高Q值，对微谐振器的真空封装进行了研究。气体分子的阻尼降低了微谐振器的Q因子。提出了采用玻璃-硅阳极键合和非蒸散吸气剂的真空封装方法，并将其应用于传感器的制作.研制了一种采用静电激励和电容检测的硅谐振式角速率传感器。设计并实现了静电伺服驱动与检测电路、自激振荡电路和检测谐振稳频电路.研制了一种采用电磁激励、电容检测的硅谐振式角速率传感器。封装后的传感器工作正常，Q值高。为了制作这种传感器，研制了一种新型的反应离子刻蚀系统.提出了一种制作窄细硅梁谐振器的新工艺。通过采用XeF_2干法刻蚀和热SiO_2工艺，实现了60 μ m方形截面的硅梁.研究了大振幅振动的压电激励方法。压电薄膜的制备方法对压电性能有很大的影响。沉积方法应在未来进行研究。

In this study, the developement of novel micromachining processes and the fabrication of resonant sensors were done. Summary is as follows.1. For making high sensitive micro resonator, the process for fabricating thin cantilever having an opposed electrode with a very narrow gap for SPM application was established. Thickness of the silicon cantilever and the gap between the cantilever and a glass substrate were less than 1mum. The novel drying method was developed for avoiding stiction by the surface tension force of liquid.2. Vacuum packaging of micro resonator was studied for realizing high Q factor. Damping by gas molecules degrade the Q factor of the micro resonator. Vacuum packaging method using glass-silicon anodic bonding and non-evaporable getter was developed and applied to the sensor fabrication.3. A silicon resonant angular rate sensor using electrostatic excitation and capacitive detection was developed. For this device, driving and detection circuit, self oscillation circuit, and detective resonant frequency stabilizing circuit for electrostatic servo were realized.4. A silicon resonant angular rate sensor using electromagnetic excitation and capacitive detection was developed. Packaged sensor was work and had high Q factor. For the fabrication this sensor, a new type reactive ion etching system was developed.5. Novel process for making thin and narrow silicon beam of resonators was developed. By this process using XeF_2 dry etching and thermal SiO_2, a silicon beam having 60mum square cross-section beam was realized.6. Piezoelectric excitation method for large amplitude vibration was studied. Deposition method of piezoelectric thin film largely affected the piezoelectric properties. Deposition method should be investigated in future.