Research On Monolithic Integrated Two - Dimensional Magnetic Sensor

In this paper, on the basis of the cubic structure silicon magnetic sensitivity transistor, the basic structure of the monolithic integration two-dimensional magnetic field sensor which constructed by four silicon magnetic sensitivity transistors(SMST1, SMST2, SMST3 and SMST4) and four load resistances(RL1, RL2, RL3 and RL4) was given, and it included four bases(B1, B2, B3 and B4), four collectors(B1, B2, B3 and C4) and four emitters(E1, E2, E3 and E4). By analyzing the working principle of the silicon magnetic sensitivity transistor, this paper gave the working principle of the monolithic integration two-dimensional magnetic field sensor, the theoretical analysis showed that the monolithic integration two-dimensional magnetic field sensor can detect twodimensional magnetic field. On this basis, the ATLAS software was used to establish the simulation structure model, and study the impact of the base region length L, the collector size SC and the base region width w on the IC-VCE property and magnetic property of the monolithic integration two-dimensional magnetic field sensor, and optimize the structure size.Based on the above, this paper adopted MEMS technology to design and fabricate the monolithic integration two-dimensional magnetic field sensor chip on <100> orientation monocrystalline silicon substrate with high resistivity and achieved the chip packaging. At the room temperature, the IC-VCE property and magnetic property of the monolithic integration two-dimensional magnetic field sensor after packaging were tested and the static characteristic were calibrated. The experimental results showed that, under the conditions of the same VCE and IB, the voltage magnetic sensitivity and the current magnetic sensitivity of the four silicon magnetic sensitivity transistors of the monolithic integration two-dimensional magnetic field sensor with the base region length L is 140 μm is higher than the monolithic integration two-dimensional magnetic field sensor with the composite base region length L is 180 μm. When VCE=5.0 V and IB=4.0 mA, the magnetic sensitive direction of the two silicon magnetic sensitivity transistors(SMST1 and SMST3) of the monolithic integration two-dimensional magnetic field sensor(L=140 μm) along x axis is opposite, and the voltage magnetic sensitivity is 114.6 mV/T and 108.3 mV/T respectively, the magnetic sensitive direction of the two silicon magnetic sensitivity transistors(SMST2 and SMST4) along y axis is opposite, and the voltage magnetic sensitivity is 106.4 mV/T and 111.4 mV/T respectively, at the same time, the magnetic property was studied when the monolithic integration two-dimensional magnetic field sensor rotated in the uniform magnetic field along z axis, the results shows that the differential output voltage of the monolithic integration two-dimensional magnetic field sensor along x axis and y axis changed along with the rotation angle respectively, and the two-dimensional magnetic field can be detected. The research results show that the four silicon magnetic sensitivity transistors of the monolithic integration two-dimensional magnetic field sensor not only have the high magnetic sensitivity and good consistency, but also can achieve the measurement of the two-dimensional magnetic field.