BPN351: MEMS-Based Magnetic Probe Microscopy


A scanning-probe magnetic microscopy based on a high resolution magnetic tunnel junction (MTJ) sensor is under construction. MTJ sensors are highly sensitive magnetic field sensors but suffer from large 1/f noise. We have developed a new approach for reducing the 1/f noise in an MTJ sensor by using a MEMS resonator to mechanically modulate the magnetic field signal to a high frequency. MEMS actuators are uniquely suited to achieve both precise, micron-scale control of the average sample-to-sensor separation and to AC modulate the separation and MTJ signal at a very high frequency (>10kHz). We have developed a fabrication process where the MTJ sensor is fabricated first on the surface of an SOI wafer. Next, MEMS actuators are fabricated in a two step deep reactive ion etching process. We have demonstrated that the actuator designs work and began the final MTJ-MEMS layout. Integrated devices are currently under fabrication and will be characterized subsequently.

Project end date: 01/29/10

Publication date: 
August 11, 2009
Publication type: 
BSAC Project Materials (Final/Archive)
PREPUBLICATION DATA - ©University of California 2009

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