Research Of GaAs-Based Hall Sensor

As an important branch of the modern sensor industry,magnetic sensors are used in various applications,with the scale of millions per year.Hall sensor,is a principal member of magnetic sensors,and widely used in the fields of automotive electronics and communication electronics since it has the advantages such as small size,low cost,high sensitivity,high reliability,low power consumption,high signal-to-noise ratio and high temperature stability.Thanks to the development of compound semiconductors,Hall sensors with higher-sensitivity can be made of materials such as GaAs and InSb today.Compared with those made of silicon and germanium materials,GaAs-based Hall sensors have an improved temperature stability,and a higher magnetic field sensing sensitivity.In this thesis,a simulation study is carried out on the one-dimensional GaAs-based Hall sensor,through which,part of the factors affecting its performance are analyzed,on this basis,the three-dimensional GaAs-based Hall sensor is also studied,and a simple process three-dimensional GaAs-based Hall sensor as well as the corresponding hardware and software support system are designed as well.Firstly,the thesis briefly describes the development status of Hall sensors abroad and at home,states the necessity of developing high performance GaAs-based Hall sensors,introduces the basic principle of Hall sensors,and analyzes the advantages of GaAs-based Hall sensors.A study is carried out on the one-dimensional GaAs-based Hall sensor with the semiconductor process and device simulation method(TCAD,Technology Computer Aided Design),through which,part of the factors affecting its performance is investigated,including the preparation process and shape of the active region as well as the shape and position of contact electrodes,etc.Aiming these factors,the author proposes the measures to improve the performance of the one-dimensional GaAs-based Hall sensor,for example,the active region should adopt the "cross" structure prepared with the epitaxial process;the contact electrodes at the bias and ground terminals should be long as far as possible,and the contact electrodes at the Hall voltage output terminal should be as short as possible.On this basis,a new-type three-dimensional GaAs-based Hall sensor which uses a simple planar process to realize spatial three-dimensional magnetic field sensing,is designed aiming to the complex process of three-dimensional GaAs-based Hall sensors.Furthermore,the designed three-dimensional GaAs-based Hall sensor is studied with the TCAD simulation method;various factors affecting its performance,including the doping concentration of epitaxial layers,the material of the isolation layer,the shape of the electrode support layer,etc.are investigated;and the doping method and the shape of the electrode support layer enabling this three-dimensional GaAs-based Hall sensor to have a higher magnetic field sensing sensitivity are proposed.In addition,the paper also develops the preparation process of the three-dimensional GaAs-based Hall sensor,which is delivered to Chengdu HiWafer Semiconductor Co.,Ltd for tape-out using the advanced GaAs process.Finally,a software and hardware support system are designed for the threedimensional GaAs-based Hall sensor.And the performances of the three-dimensional GaAs-based Hall sensor is tested,the test results show that three-dimensional Hall sensor can realize spatial three-dimensional magnetic field sensing,which is combined with the designed software and hardware support system to realize the sensing,analysis and recording of the three-dimensional magnetic field.