隧穿磁电阻（TMR）传感器因其具有体积小、功耗低、灵敏度高和易于集成等特点，在无损检测、生物医学测量、角度测量以及小型化应用场合等领域显示出了广阔的应用前景，TMR传感器的核心结构为磁性隧道结（MTJ）。论文调研了目前MTJ薄膜体系结构、TMR传感器的加工工艺、线性化方法和形成惠斯通电桥结构TMR传感器的方法。本文通过对目前形成惠斯通电桥结构TMR传感器的方法进行分析和对比，设计和加工了一种方案简单的全桥结构TMR传感器。论文基于Stoner-Wohlfarth模型建立了一种简化的MTJ单畴模型，对 、 的MTJ在沿自由层易轴施加偏置磁场下的传输特性进行了仿真计算，并对由该两种MTJ组成的全桥结构的输出特性进行了仿真计算。对MTJ薄膜的制备进行了尝试和探索，为之后优化薄膜工艺打下了基础。对单个和串联MTJ进行了加工和测试，并对沿自由层易轴施加偏置磁场下的传输特性进行了测试，结合仿真结果证明了本文设计的全桥结构TMR传感器具有可行性。论文设计并加工了一种全桥式TMR传感器，对沿参考层负向施加不同大小偏置磁场下全桥式TMR传感器的传输特性进行了仿真分析和实际测试，结果表明当施加65Oe偏置磁场时，全桥式TMR传感器具有1.94mV/V/Oe的灵敏度、0.21Oe的磁滞和1.7%的非线性度。论文设计和加工了一种半桥组装式TMR传感器，对其工艺结果进行了分析，并对组装后的TMR传感器进行了输出特性和噪声特性的测试，结果表明所加工出的传感器能在1~12V的电压范围内正常工作，灵敏度为6mV/V/Oe左右，等效磁场噪声为0.7~12.2nT/Hz1/2@10Hz和60~720pT/Hz1/2@1kHz。将半桥组装式TMR传感器与后续放大电路和调零电路进行集成形成样机，在磁屏蔽环境下对样机在±0.9Oe范围内进行了测试，该样机灵敏度为3.04V/Oe，磁滞为733nT，非线性度为4.8‰，零偏电压为152mV，对应的零偏磁场为0.05Oe，等效磁场噪声为38nT/Hz1/2@10Hz和2.6nT/Hz1/2@1kHz，同时还对该样机在地磁场环境中进行了转角测试，结果符合正弦函数。设计并加工了NiFe磁通聚集结构，并对其聚磁效果进行了仿真和实际测试，TMR传感器灵敏度得到了明显的提升。
The tunneling magnetoresistance (TMR) sensors have shown a broad prospect in the fields of nondestructive testing, biomedical measurement, angle measurement and miniaturization applications due to its small size, low power consumption, high sensitivity and easy integration. The core structure of the TMR sensor is magnetic tunnel junctions (MTJs). The structure of MTJ thin film stack, processing technology of TMR sensors, linearization methods of MTJs and the methods of forming Full-Wheatstone bridge structure TMR sensors were investigated. Analyzing and comparing the methods of forming full bridge TMR sensors, a full bridge TMR sensor was designed and fabricated.Based on the Stoner-Wohlfarth model, a simplified single domain model of MTJ was established to simulate the transmission characteristics of and MTJs, and the output characteristics of the full bridge structure composed of the two kinds of MTJs were also simulated. The preparation of MTJ thin film was tried and explored, which laid a foundation for the optimization of MTJ thin film. The single and series MTJs were fabricated and tested, and the transmission curves were tested under the bias magnetic field applied along the easy-axis of the free layer. Combining the simulation results and the experiment results, the feasibility of the full bridge structure of TMR sensors was proved.A full bridge TMR sensor was designed and fabricated. The transmission curves of the full bridge TMR sensor were simulated and tested under applying the different bias magnetic field along the negative direction of the reference layer. The results showed that under the 65Oe bias magnetic field, the full-bridge TMR sensor has a sensitivity of 1.94mV/V/Oe, a hysteresis of 0.21Oe and a nonlinearity of 1.7%.In this thesis, a kind of TMR sensor was designed and processed by assembling two half-bridges, and the output characteristics and noise characteristics of the TMR sensors were tested. The results showed that the working voltage range of the TMR sensors is 1V to 12V, the sensitivity was about 6mV/V/Oe and the magnetic field noise was 0.7~12.2nT/Hz1/2@10Hz and 60~720pT/Hz1/2@1kHz. The TMR sensor was integrated with amplifying circuit and zeroing circuit. The prototype was tested in the range of ±0.9Oe under magnetic shielding environment. The sensitivity of the prototype was 3.04V/Oe, the hysteresis was 733nT, the nonlinearity was 4.8‰, the offset voltage was 152mV, the offset magnetic field was 0.05Oe and the magnetic field noise was 38nT/Hz1/2@10Hz and 2.6nT /Hz1/2@1kHz. The prototype was tested in the geomagnetic field environment under the different angles, and the results accorded with the sine function. The NiFe magnetic flux concentration structure was designed, simulated and fabricated. The sensitivity of TMR sensor with the magnetic flux concentration structure was improved obviously.
