Integrated 3-D magnetic sensors based on an n-p-n transistor

A novel solid-state silicon sensor that is sensitive to all three components of the magnetic-field vector is presented. The sensor is based on the magnetotransistor principle and is fabricated in standard bipolar IC technology. The lateral part of the collector current has been used to sense the component of the magnetic field perpendicular to the surface of the chip, while the vertical part of the current has been used to measure the in-plane magnetic-field vector. The achieved spatial resolution of the measurement (8 x 10 x 20 microns) is dependent on the geometry of the active region of the device. (Author)