单片集成三维磁场/三轴加速度/微压多功能传感器模型构建与集成化研究

In this project, a monolithic integrated sensor model with three-dimensional magnetic field, three-axis acceleration and micro-pressure, is proposed aimed at solving the problem of monolithic integration of multifunctional physical sensor. The sensor model is constructed based on that nc-Si thin films have excellent physical properties of high gauge factor, high carrier mobility and wide optical band-gap, and it also adopts the method by combining the heterojunction magnetic sensitive transistor with nc-Si thin films transistor. Above that, a theory of the monolithic integration of the multifunctional sensor, which can realize the functions of three-dimensional magnetic field, three-axis acceleration and micro-pressure, is proposed. Through exploring the sensitive mechanism, characterization and cross-interference problems of the multifunctional sensor, it can be realized that the design of the message sensitive units of the multifunctional sensor is improved. Through microelectromechanical systems (MEMS) and in-situ doping of nc-Si thin films, the fabrication and packaging of the monolithic multifunctional sensor chip is achieved on the <100> orientation silicon with high resistivity. The structure can measure three physical quantities (seven information contents)--magnetic field, acceleration and pressure, at the same time. Because of the good physical characteristics of nc-Si thin films, the monolithic multifunctional sensor has the advantages of high sensitivity, low cross-interference and superior temperature stability, which lays a foundation for the multi-functionalization, miniaturization and integration of the sensor and the research of thin film sensor. It has very important applications in the fields of aerospace, environmental monitoring and health, etc.

本项目针对多功能物理量传感器单片集成化问题，利用纳米硅薄膜具有高应变因子、高载流子迁移率和宽光学带隙的优异物性，采用异质结硅磁敏三极管和纳米硅薄膜晶体管相结合方法，提出三维磁场/三轴加速度/微压多功能传感器单片集成化结构模型。在此基础上，建立三维磁场、三轴加速度和微压多功能传感器单片集成化理论，探究多功能传感器各物理量敏感机理、特性及相互交叉影响问题，达到单片集成多功能传感器各信息量敏感单元优化设计。基于微机械加工技术（MEMS）和纳米硅薄膜原位掺杂技术，在<100>晶向高阻单晶硅上实现多功能传感器芯片单片集成化工艺制作和封装，该结构能够同时对磁场、加速度和压力三个物理量（7个信息量）进行测量。因纳米硅薄膜物性优异，单片集成多功能传感器具有高灵敏度、交叉干扰小和温度稳定性好等优点，为传感器多功能化、小型化和集成化及薄膜型传感器研究奠定重要基础，在航空航天、环境监测和医疗等领域具有重要应用。

本项目针对三维磁场/三轴加速度/微压多物理量传感器单片集成化问题，提出三维磁场/三轴加速度/微压多功能传感器单片集成化结构模型。为实现三维磁场（Bx、By和Bz）测量，在开展异质结硅磁敏三极管及集成化差分结构等研究基础上，分别构建了两种不同集成化结构模型，一种基于异质结硅磁敏三极管、霍尔元件相结合方法，由不同集成磁敏感器件构建三维磁场传感器模型，另一种基于霍尔效应和磁场集中器原理构建同一种敏感器件组成的空间三维磁场传感器模型。为实现三轴加速度（ax、ay和az）测量，基于弹性元件和压敏电阻构建三轴加速度传感器结构模型，弹性元件包括四个L型双梁、两个质量块及中间双梁，十二个压敏电阻分布在L型双梁和中间双梁的根部，分别构成三个惠斯通电桥结构实现三轴加速度（ax、ay和az）测量；压力传感器由方形硅膜和位于边缘区域的四个压敏电阻构成，利用扩散硅压阻效应可实现外加压力（P）测量。在此基础上，建立了三维磁场、三轴加速度和微压多功能传感器单片集成化理论，探究多功能传感器各物理量敏感机理和特性，分别采用TCAD-Atlas软件构建三维磁场传感器仿真模型，并且采用ANSYS Workbench软件构建磁场集中器、三轴加速度传感器和压力传感器结构仿真模型，分别进行传感器特性仿真分析，完成了传感器设计优化。综合上述，基于微机械加工技术（MEMS），在<100>晶向高阻单晶硅上实现多功能传感器芯片单片集成化工艺制作和封装，该结构实现对磁场、加速度和压力三个物理量（7 个信息量）同时测量，为传感器多功能化、小型化和集成化研究奠定重要基础，在航空航天、环境监测和医疗等领域具有重要应用。