硅微机械陀螺片上旋转调制高精度实现方法研究

Silicon micromachined gyroscope as basic core device of inertial navigation system has important application demand in the national defense field. This study first proposes integrated mechanical structure and fabrication method of on-chip rotational silicon micromachined gyroscope based on MEMS technology, which aim is to decrease error induced by bias drift of MEMS gyroscope with order of magnitude. Compared with the existing research scheme, the presented scheme first presents single-chip integration of rotational structure with MEMS gyroscope under micro/nano scale. This scheme has characteristic of extremely small volume, simple fabrication process, large rotation rate and high-precision assembling. First, quantitative model of rotation effect on slowly-variable drift of gyroscope is established. Meanwhile, relation between on-chip structure, vibration parameters of rotation platform and suppression time of bias drift is also established. Then, the on-chip structure is designed and fabrication method based on full dry etching process and glass-metal-silicon bonding is developed. Optical-electric measurement platform is built to test the structure parameters. Measurement control circuits of the gyroscopes and rotational platform are designed, respectively. Finally, principle prototype of the proposed scheme is obtained to evaluate order of magnitude of bias drift suppression. This scheme is expected to be important way to develop next-generation chip-level rotational MEMS gyroscope after fiber optic gyroscope, which is an extremely leading-edge work.

硅微机械陀螺作为惯性导航系统的基本核心元器件，在国防军事领域有着重要的应用需求。本项目首次提出了基于Micro-electromechanical system (MEMS)技术的硅微机械陀螺片上旋转调制一体化结构及其制备方法，以实现陀螺零位漂移误差数量级上的降低，从而显著提高陀螺精度。相比传统的旋转机构，该结构首次实现微纳尺度下旋转机构与陀螺单芯片集成，具有体积极小、转速高、装配精度高等优点。首先建立转动方式对陀螺漂移调制效果的量化模型以及旋转平台结构参数、振动参数与零漂抑制倍数的关系模型；接着设计片上一体化结构并开发基于玻璃-金属-硅键合的全干法刻蚀工艺制备方法并得到样件；搭建光/电联用测试平台获得结构参数，分别设计陀螺、旋转调制平台测控电路，最终形成原理样机并测试陀螺零漂误差降低的数量级。该方法有望成为创新发展继光纤陀螺之后新一代芯片级旋转调制陀螺的重要手段，是一项前沿性极强的工作.

MEMS陀螺作为角速率敏感元件是惯性导航系统的基本核心元件，具有体积小、重量轻、成本低等特点，在国防军事领域有着重要的应用需求。当前，基于MEMS技术的高端工业装备以及航空、航海用陀螺几乎全被国外企业垄断，国内企业在陀螺敏感组件核心技术、工艺水平、生产装备、产品品质等方面与国外同行相比大约落后5-10年。因此，探索MEMS陀螺高精度实现新方法是打破当前困局、赶超国外先进技术水平的重要手段之一。本项目针对工业、航空等领域重大装备对高精度惯性敏感核心元件的迫切要求，首次提出了基于MEMS技术的硅微机械陀螺片上旋转调制一体化结构及其制备方法，以实现陀螺零位漂移引入的误差在数量级上的降低，极大提高陀螺精度。本项目研究内容暨研究成果为：（1）建立了转动方式对陀螺漂移调制效果的量化模型以及旋转平台结构参数、振动参数与零漂抑制倍数的关系模型；（2）设计了片上一体化结构并开发了基于玻璃-金属-硅键合的全干法刻蚀工艺制备方法并制备样件；（3）针对该样件设计了光/电联用测试平台获得结构参数，分别设计陀螺、旋转调制平台测控电路，最终形成原理样机并进行测试。传统旋转调制技术需要借助外部大尺寸旋转机构（1m^3量级）为陀螺仪提供外部激励，使最终角速率测量方案丧失了MEMS陀螺的低成本量产与小体积应用优势；而本项目研发的片上旋转调制技术则将旋转机构与MEMS陀螺敏感芯片单片同步加工，突破上述传统旋转调制技术局限性，是在MEMS陀螺高精度研究中具有颠覆性的技术。