Research On The Properties Of AlGaN/GaN HEMT Hall Sensors

Hall sensors are magnetic field sensors made according to the Hall effect.Hall effect sensors made from semiconductor materials have been widely used in industrial control,consumer electronics,and automotive applications due to their advantages in size,structure,service life,and application fields.And other fields.The AlGaN/GaN high electron mobility transistor Hall sensor has many advantages compared with other heterojunction or multilayer quantum well structure Hall sensors,such as: a higher carrier mobility can increase the Hall voltage,can Work at a higher frequency;the large forbidden band width makes the device have better temperature stability characteristics,which reduces the interference of external temperature and reduces Hall offset;in addition,it has the advantages of high temperature resistance and radiation resistance.In this paper,based on the AlGaN epitaxial structure,the Hall sensor of AlGaN/GaN high electron mobility transistors with round and inverted trapezoidal electrode structures was prepared by thermal evaporation and photolithography.Both round and inverted trapezoidal electrodes use a horizontally symmetrical structure.Firstly,the three aspects of the working principle,performance parameters and preparation of the Hall device are introduced.Finally,the Hall sensor platform built by ourselves is used to detect the Hall sensor of the two electrode structures of circular and inverted trapezoid respectively.After measurement,the maximum Hall voltage of the Hall device with a circular structure under a magnetic field of 250 mT is 6.01 mV.However,a larger Hall offset voltage reaches 67% of the total voltage.In the Hall device experiment with inverted trapezoidal electrode structure,the relationship between the Hall voltage at the output of the three groups of samples and the voltage/current at the input were measured,and the relationship between the Hall voltage and the magnetic field and the offset voltage under different excitation sources were compared.The measurement results show that under the magnetic field strength of 320 mT,the Hall device of the inverted trapezoidal electrode has a higher Hall voltage,reaches 18.96 mV under the condition of the excitation source current source of 1mA,and has a smaller offset characteristic,showing better Linear relationship.