Research And Design Of GaAs-based Heterojunction 3D Hall Sensor

The three-dimensional Hall sensor appeared to meet the rapid development of modern industry.Most of the current three-dimensional Hall sensors are made of silicon materials,which have good process compatibility.However,due to the low carrier mobility and narrow band gap of silicon materials,silicon-based Hall sensors have low sensitivity and temperature The stability is poor.The GaAs material has high carrier mobility and large band gap.The Hall sensor prepared with it has higher sensitivity and better temperature stability,and can utilize the high mobility carriers of GaAs-based heterojunction Features to further improve the performance of the sensor.In this paper,the influencing factors of the GaAs-based heterojunction level Hall sensor are firstly explored,and the influencing factors of the heterojunction level Hall sensor are studied in detail using sentaurus TCAD software.Furthermore,the shape of the vertical Hall sensor is optimized,and the influencing factors of the GaAs-based heterojunction vertical Hall sensor are explored.Finally,based on the research of heterojunction horizontal Hall sensor and heterojunction vertical Hall sensor,a GaAs-based heterojunction three-dimensional Hall sensor based on planar technology was designed and related performance was tested.Through the above research,the following main research results have been obtained:1.Studies have shown that the doping concentration and doping depth of the delta layer will have a greater impact on the sensitivity of the heterojunction level Hall sensor.The position of the delta layer and the doping concentration of the cap layer will have a slight impact on the sensitivity.The contact electrode is located on the side wall of the upper half of the cap layer and the isolation layer,which is beneficial to improve the sensitivity of the sensor.2.Adding two small crosses to the main part of the heterojunction vertical Hall sensor can improve the sensitivity of the sensor,and when the length and width of the two small crosses make the shape of the two areas close to the position of the cross and the two small crosses Being close to each other helps to improve sensitivity,and the increase in the length and width of the main body will have a negative impact on sensitivity.At the same time,according to the research results of the horizontal heterojunction Hall sensor,the delta doped layer,the doping concentration of the cap layer and the placement position of the contact electrode were investigated for the vertical sensor.The influence of the three on the vertical sensor is the same as that of the horizontal sensor.Similarly,except for the delta doping depth,the effect is the opposite of the level sensor.3.According to the research results of the horizontal sensor and the vertical sensor,a heterojunction three-dimensional Hall sensor under planar technology was designed,and the structure of the three-dimensional sensor was tested with different influencing factors to improve the sensitivity of the sensor and try to make X The sensitivities of,Y,and Z directions are close to each other.According to the test results,the structure of the sensor is determined.The sensitivity in the Z direction is about 0.29 V/TV,and the sensitivity in the X and Y directions is about 0.28V/TV.After determining the structure of the three-dimensional sensor,two preparation schemes(under the planar process)are provided,each of which has advantages and disadvantages,and can be selected according to sensor requirements and process requirements.