DocumentCode :
1428362
Title :
Three-axes monolithic silicon low-g accelerometer
Author :
Bütefisch, Sebastian ; Schoft, Axel ; Büttgenbach, Stephanus
Author_Institution :
Tech. Univ. of Braunschweig, Germany
Volume :
9
Issue :
4
fYear :
2000
Firstpage :
551
Lastpage :
556
Abstract :
In this paper, four different designs for a new three-axes monolithic low-g acceleration sensor are presented. The silicon spring mass system of the sensor is fabricated in a single step by anisotropic wet chemical etching in KOH using [111] planes as physical etch stop. The orientation of the supporting beams of the spring-mass systems allows the seismic mass to move in a direction orthogonal to the [111] planes. Four mass-spring systems, each one rotated by 90/spl deg/, enables the detection of three components of the acceleration vector using capacitive readout. Two alignment structures are presented meeting the high requirements in terms of mask alignment, which are necessary when using the described etch technique. A new space saving compensation structure protecting the convex edges of the seismic masses during the etch process was realized and compared with standard solutions. The sensors performance was characterized and is demonstrated.
Keywords :
accelerometers; capacitive sensors; compensation; elemental semiconductors; etching; masks; microsensors; silicon; Si; acceleration sensor; anisotropic wet chemical etching; capacitive readout; compensation structure; convex edges; etch technique; low-g accelerometer; mask alignment; physical etch stop; seismic mass; seismic masses; spring mass system; supporting beams; Acceleration; Accelerometers; Anisotropic magnetoresistance; Chemical sensors; Protection; Sensor phenomena and characterization; Sensor systems; Silicon; Springs; Wet etching;
fLanguage :
English
Journal_Title :
Microelectromechanical Systems, Journal of
Publisher :
ieee
ISSN :
1057-7157
Type :
jour
DOI :
10.1109/84.896778
Filename :
896778
Link To Document :
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