The Design Of Gallium Arsenide Horizontal Hall-effect Sensor

Hall-effect sensor is known as the sensor ranked 3th in the world.It is the most productive magnetic sensor and has the highest market share.Every year,hundreds of millions of Hall-effect sensors are used in the fields,including consumer electronics,industrial automation,automotive electronics,medical and health systems,aerospace and military,etc.The Hall-effect sensor chip is mainly composed of two parts: Hall plate and interface circuits.As the sensing element,the selection and design of the Hall plate will directly affect the performance of the Hall-effect sensor.As the second-generation semiconductor,gallium arsenide,its Hall plate has better performances on sensitivity,temperature and weak magnetic field detection than silicon's.With the development of 5G technology,many foundries for gallium arsenide have been built in China.Therefore,the study of gallium arsenide Hall-effect sensors at this stage is of great significance.Firstly,the thesis investigated the market and development trend of Hall-effect sensor,studied the technology development,performance improvement and innovative applications of Hall-effect sensor in JSSC,surveyed the domestic main development of Hall-effect sensor and domestic and foreign main development of gallium arsenide Halleffect sensor over the past 10 years,summed that the gallium arsenide Hall-effect sensor has a significant advantage in weak magnetic field measurement,high sensitivity,high linearity and wide operating temperature range.Secondly,taking the Hall plate as the starting point,the thesis introduced the physical principle of the Hall plate,the type of the Hall plate: horizontal and vertical;the common shape of the horizontal Hall plate,the working mode: voltage mode and current mode,commonly used performance parameters,equivalent circuit mode,manufacturing materials and main applications.Thirdly,the thesis explored the establishment of the finite element model of the gallium arsenide Hall plate and its inherent physical mechanism,distinguished the numerical expression of Hall mobility and mobility of gallium arsenide with different concentration and temperature,studied the surface Fermi energy pinning caused by the surface state,which leads to a thinner channel layer of the gallium arsenide Hall plate,explored the influence of different shape narrow cross-shaped Hall plate on sensitivity,manufactured a narrow cross-shaped Hall plate base on gallium arsenide process technology,compared the test and simulation results of the gallium arsenide Hall plate,introduced a circuit model of narrow cross-shaped Hall plate.Finally,this thesis studied the interface circuits design of the gallium arsenide Hall plate;discussed the advantages and disadvantages of its interface circuits on the PCB,pHEMT and silicon process technology;introduced the circuits frames of the linear and switch Hall-effect sensors,described the characteristics of instrumentation amplifier,auto-zeroing amplifier and chopper operational amplifier;built a rail-to-rail operational amplifier,PTAT current source and switched capacitor filter based on 0.18?m BCD process.