A CMOS-MEMS BEOL 2-axis Lorentz-Force magnetometer with device-level offset cancellation
Sánchez-Chiva, Josep Maria (Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica)
Valle, Juan (Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica)
Fernández Martínez, Daniel (Institut de Física d'Altes Energies)
Madrenas, Jordi (Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica)

Date:	2020
Abstract:	Lorentz-force Microelectromechanical Systems (MEMS) magnetometers have been proposed as a replacement for magnetometers currently used in consumer electronics market. Being MEMS devices, they can be manufactured in the same die as accelerometers and gyroscopes, greatly reducing current solutions volume and costs. However, they still present low sensitivities and large offsets that hinder their performance. In this article, a 2-axis out-of-plane, lateral field sensing, CMOS-MEMS magnetometer designed using the Back-End-Of-Line (BEOL) metal and oxide layers of a standard CMOS (Complementary Metal-Oxide-Semiconductor) process is proposed. As a result, its integration in the same die area, side-by-side, not only with other MEMS devices, but with the readout electronics is possible. A shielding structure is proposed that cancels out the offset frequently reported in this kind of sensors. Full-wafer device characterization has been performed, which provides valuable information on device yield and performance. The proposed device has a minimum yield of with a good uniformity of the resonance frequency fr¯¯¯=56. 8 kHz, σfr=5. 1 kHz and quality factor Q¯¯¯=7. 3, σQ=1. 6 at ambient pressure. Device sensitivity to magnetic field is 37. 6 fA⋅μT−1 at P=1130 Pa when driven with I=1mApp.
Grants:	Agencia Estatal de Investigación RTI2018-099766-B-I00
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	MEMS ; Magnetic sensor ; Magnetometer ; Lorentz-force ; Offset suppression ; Micromachined Resonator ; Micromechanical oscillator
Published in:	Sensors (Basel, Switzerland), Vol. 20, issue 20 (Oct. 2020) , art. 5899, ISSN 1424-8220

DOI: 10.3390/s20205899
PMID: 33086559

20 p, 8.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut de Física d’Altes Energies (IFAE)
Articles > Research articles
Articles > Published articles