Lorentz force transduction for RF micromechanical filters

2011 16th International Solid-State Sensors, Actuators and Microsystems Conference ◽

10.1109/transducers.2011.5969690 ◽

2011 ◽

Cited By ~ 1

Author(s):

S. Forouzanfar ◽

R. R. Mansour ◽

E. M. Abdel-Rahman

Keyword(s):

Lorentz Force ◽

Micromechanical Filters ◽

Force Transduction

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Lorentz-force transduction for RF micromechanical filters

Journal of Micromechanics and Microengineering ◽

10.1088/0960-1317/22/3/035018 ◽

2012 ◽

Vol 22 (3) ◽

pp. 035018 ◽

Cited By ~ 1

Author(s):

Sepehr Forouzanfar ◽

Raafat Mansour ◽

Eihab Abdel-Rahman

Keyword(s):

Lorentz Force ◽

Micromechanical Filters ◽

Force Transduction

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Development and post-dicing wet release of MEMS magnetometer: an approach

Microelectronics International ◽

10.1108/mi-12-2020-0081 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Aditi ◽

Supriyo Das ◽

Ram Gopal

Keyword(s):

Lorentz Force ◽

Ambient Pressure ◽

Magnetic Hysteresis ◽

Laser Doppler Vibrometer ◽

Anodic Bonding ◽

Quality Factors ◽

Wafer Level ◽

Content Type ◽

Positive Photoresist ◽

Force Transduction

Purpose Si-based micro electro mechanical systems (MEMS) magnetometer does not require specialized magnetic materials avoiding magnetic hysteresis, ease in fabrication and low power consumption. It can be fabricated using the same processes used for gyroscope and accelerometer fabrication. The paper reports the dicing mechanism for the released MEMS xylophone magnetic sensor fabricated using wafer bonding technology and its characterization in ambient pressure and under vacuum conditions. The purpose of this paper is to dice the wafer bonded Si-magnetometer in a cost-effective way without the use of laser dicing and test it for Lorentz force transduction. Design/methodology/approach A xylophone bar MEMS magnetometer using Lorentz force transduction is developed. The fabricated MEMS-based xylophone bars in literature are approximately 500 µm. The present work shows the released structure (L = 592 µm) fabricated by anodic bonding technique using conducting Si as the structural layer and tested for Lorentz force transduction. The microstructures fabricated at the wafer level are released. Dicing these released structures using conventional diamond blade dicing may damage the structures and reduce the yield. To avoid the problem, positive photoresist S1813 was filled before dicing. The dicing of the wafer, filled with photoresist and later removal of photoresist post dicing, is proposed. Findings The devices realized are stiction free and straight. The dynamic measurements are done using laser Doppler vibrometer to verify the released structure and test its functionality for Lorentz force transduction. The magnetic field is applied using a permanent magnet and Helmholtz coil. Two sensors with quality factors 70 and 238 are tested with resonant frequency 112.38 kHz and 114.38 kHz, respectively. The sensor D2, with Q as 238, shows a mechanical sensitivity of 500 pm/Gauss and theoretical Brownian noise-limited resolution of 53 nT/vHz. Originality/value The methodology and the study will help develop Lorentz force–based MEMS magnetometers such that stiction-free structures are released using wet etch after the mechanical dicing.

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