Magnetic-field measurements using an integrated resonant magnetic-field sensor

The present paper introduces a magnetic-field sensor based on a resonating single-crystal silicon structure. The excitation of the resonator is achieved by the Lorentz force generated by a sinusoidal current flowing through a rectangular coil deposited on the surface of the structure. The amplitude of the vibration, which is proportional to the magnetic field, is detected by sensing capacitors. Because of the high-quality factor of the resonator, a lower detection limit of 1 nT, or even smaller might be realised when the device is vacuum-packaged. This paper describes the working principle, the fabrication procedure as well as open- and closed-loop measurement results. (C) 1998 Elsevier Science S.A. All rights reserved.