A complementary magnetic field sensor using magnetic tunnel junction

A complementary planar magnetic field sensor for the compass application was designed and successfully fabricated. Additionally, an MTJ with well-crystalline MgO film was also fabricated on an inclined surface as the Z-axis sensor. The weak temperature dependence was found in the planar magnetic sensor and a good consistency was found between the package level and the wafer level measurements. The operation point drift at the temperature of 185
^o
C is about 0.2%. Besides, the geomagnetic field was measured by the planar magnetic sensor and its sine wave-like response demonstrated the capability of the planar sensor. The sensitivities of the magnetic sensor are 10.58 mV/Oe (X-sensor) and 11.1 mV/Oe (Y-sensor).