【作者】 吴俊；

【导师】 刘骅锋；

【作者基本信息】 华中科技大学 ， 精密测量物理， 2022， 硕士

【摘要】 超高灵敏度原子磁力仪在生物医疗、无损检测和基础科学等领域得到越来越广泛的应用。随着科技进步,对未知领域的探索驱使人们研制出越来越高灵敏度的磁力仪。基于MEMS技术的原子磁力仪因具有超高灵敏度、小体积和低功耗等优势受到国内外研究人员的广泛关注,其核心微气室的体积决定了磁力仪系统的小型化程度。本文围绕MEMS原子磁力仪核心微气室展开相关研究工作,主要内容包括:（1）详细调研各种硅基MEMS原子磁力仪和硅基MEMS气室;介绍MEMS原子磁力仪工作原理及气室制造工艺;讨论不同驰豫机制对原子磁力仪灵敏度的影响,并从原子极化矢量的布洛赫方程出发对各驰豫机制进行理论计算,完成原子磁力仪关键参数的仿真分析,初步提出100～150℃的气室工作温度以及约1.1 amg的氮气填充压强。（2）采用二氧化硅可牺牲掩膜的多深度一体化刻蚀工艺加工得到可阻止生成腔中固态反应残余物散落到作用腔的弯曲多通道结构;通过光刻、刻蚀、键合和划片等MEMS工艺完成可提高激光与原子相互作用距离的玻璃-硅-硅-玻璃四层堆叠结构的微气室制造;采用剥离工艺完成金薄膜电阻测温线圈的制造,实现测温单元片上集成化。（3）完成MEMS气室测试,包括:“可变法”气密性测试,在0.4 MPa氦压4小时后,测得气室漏率不高于5.8×10^-3 Pa·cm³/s,满足标准GJB 548B-2005;完成饱和吸收光谱测试,测得原子吸收光谱;在80～150℃内完成测温线圈温度标定实验,得到金薄膜电阻线圈阻值随温度的线性变化关系;初步开展滤光片激光加热实验,为完全无磁加热提供新思路。本文完成了MEMS原子磁力仪微气室研制,开展了气室性能测试,证明了微气室MEMS制造工艺可行性,为后续MEMS原子磁力仪的系统集成化及磁场测量奠定技术基础。更多还原

【Abstract】 Ultra-high sensitivity atomic magnetometers are widely used in biomedical,nondestructive testing and basic science fields.With the progress of science and technology,the exploration of unknown areas drives researchers to develop more and more sensitive magnetometers.Atomic magnetometers based on MEMS technology have attracted extensive attention from researchers at home and abroad because of their advantages such as ultra-high sensitivity,small size and low power consumption.The volume of the core micro vapor cell determines the overall miniaturization of the magnetometers system.In this dissertation,relevant research work is carried out around the core micro vapor cell of atomic magnetometers based on MEMS technology.The main contents include:（1）Detailed investigation of various silicon-based MEMS atomic magnetometers and silicon-based MEMS vapor cell.The working principle and vapor cell manufacturing process of MEMS atomic magnetometers are introduced.The effects of different relaxation mechanisms on the sensitivity of atomic magnetometers are discussed,and the theoretical calculation of each relaxation mechanism is carried out based on the Bloch equation of atomic polarization vector,and the simulation analysis of the key parameters of atomic magnetometers is completed.The operating temperature of the vapor cell at 100～150℃and nitrogen pressure at about 1.1 amg are proposed.（2）Using silicon dioxide as sacrificial layer,the structure is etched to different depths by a single step etching process,and a curved multi-channel structure can be fabricated to prevent the solid reaction residues from scattering into the acting cavity.A four-layer glass-silicon-silicon-glass stack micro vapor cell was fabricated by MEMS processes such as photolithography,etching,bonding and scribing.The structure can improve the laser interaction distance with atoms,the stripping process is used to fabricate the temperature measuring coil,and the temperature measuring unit is integrated on the chip.（3）Completing MEMS vapor cell test,including:"variable method"gas tightness test,under 0.4 MPa helium pressure for 4 hours,measured vapor cell leakage rate is not higher than 5.8×10^-3 Pa·cm³/s,meet the standard GJB 548B-2005.The saturated absorption spectrum was tested and atomic absorption spectrum was measured.The coil temperature calibration experiment was completed within 80～150℃,and the linear relationship between the resistance value of the gold thin film resistance coil and temperature was obtained.The experiment using a laser to heat the filter was carried out to provide a new possibility for completely non-magnetic heating.In this dissertation,the development of micro vapor cell for MEMS atomic magnetometers was completed,and the performance test of the vapor cell was carried out,which proved the feasibility of the MEMS process for micro vapor cell manufacturing,and laid a technical foundation for the subsequent system integration and magnetic field measurement of MEMS atomic magnetometers.更多还原