Fabrication of micromirror-based magnetic sensor
Cui Z., Wang X., Li Y., Tian GY.
A novel SOI wafer process was established for fabrication of micromirror-based magnetic sensor. The process offers stress-free micromechanical structures without the stiction problem encountered in conventional surface micromachining process. By using two-step etching, the thickness of suspension beams of a micromirror can be independently defined. The new process also made it possible to electroplate a permalloy layer on one side of a micromirror and to maintain a mirror like reflection surface on the other side. The magnetically actuated micromirrors have been characterised using a simple laser beam reflection and CCD camera recording system. Magnetic field detection sensitivity of about 1 degree of mirror deflection per 10 -4Tesla of field intensity has been achieved. © 2007 IOP Publishing Ltd.