Based On The Fabrication And Characteristics Of SOI Hall Magnetic Sensors

In this paper, the basic structure of SOI Hall magnetic sensor is established on SOI chip, the sensor consist of two ohmic-contact controll current electrode(VDD, VSS) and ohmic-contact Hall output terminal(VH1, VH2). The Hall output series integrated structure is proposed based on the basic structure and working principle of SOI Hall magnetic sensor, the structure includes two Hall magnetic sensor(HD1 ? HD2) with same characteristics and its working principle are discussed. The 2D simulation model and 3D simulation model were established by the ATLAS device simulation system based on the basic structure of SOI Hall magnetic sensor. The magnetic characteristic and temperature characteristic of SOI Hall magnetic sensor were simulated analysis based on the influence study of SOI chip to sensor characteristic. Through the theory study and simulated analysis of SOI Hall magnetic sensor, the simulation model of monocrystalline silicon Hall magnetic sensor was established to compare with SOI Hall magnetic sensor on magnetic characteristic and temperature characteristic. The chip layouts of SOI Hall magnetic sensor and series stuctrue SOI Hall magnetic sensor were designed by L-Edit layout design software, and the sensors were fabricated on SOI chip using MEMS and CMOS technology, chip size is 2×2 mm2. The chips were packaged using integrated circuit inside wire bonding technology.In this paper, the characteristics of single integrated SOI Hall magnetic sensor chip were tested by sensor magnetic characteristic testing system(CH-100) and high-low temperature testing chamber(GDJS-100LG-G). The influences of magnetic sensitive layer width-lengh ratio(W/L), Hall output terminal shap, Hall output terminal width(b)and series structure to SOI Hall magnetic sensors' characteristic were researched, and the structural parameters were optimized. When VDD=5.0 V, W/L=80 ?m/80 ?m and Hall output terminal width b=8 ?m, the magnetic sensitivity of SOI Hall magnetic sensor canreach 159.82 m V/T. When VDD=5.0 V, W/L=80 ?m/80 ?m and Hall output terminal width b=4 ?m, the magnetic sensitivity of SOI Hall magnetic sensor with series Hall output terminals can reach 201.83 m V/T. The results show that SOI Hall magnetic sensor have better magnetic characteristic and temperature characteristic than monocrystalline silicon Hall magnetic sensor, and the SOI Hall magnetic sensor with series Hall output terminals can realize the increase of magnetic sensitivity.