Title :
Force-balanced accelerometer with mG resolution, fabricated using Silicon Fusion Bonding and Deep Reactive Ion Etching
Author :
Van Drieënhuizen, B.P. ; Maluf, N.I. ; Opris, I.E. ; Kovacs, G.T.A.
Author_Institution :
Lucas NovaSensor, Fremont, CA, USA
Abstract :
A single crystal silicon accelerometer with mG resolution (1 G=9.81 m/s2) has been fabricated using Silicon Fusion Bonding (SFB) and Deep Reactive Ion Etching (DRIE). This allows thick devices (up to several hundred μm) to be defined with high aspect ratios (up to 25), resulting in high sensitivity and low cross-axis sensitivity. Prototypes use a hybrid approach, with a 1.0×1.5 mm2 mechanical element and a capacitive sensor interface providing closed-loop force-balancing to minimize non-linearity. The bandwidth is 1 kHz and the sensitivity is 700 mV/G. The dynamic range is 44 dB, corresponding to a resolution of 35 mG for a 5 G (full scale) device and 7 mG for a 1 G device. The resolution is currently limited by 1/f noise in the electronic interface, but will be reduced with an improved design of the capacitive sensing interface (currently in fabrication), thus resulting in sub-mG resolution
Keywords :
1/f noise; CMOS integrated circuits; accelerometers; application specific integrated circuits; capacitance measurement; microsensors; semiconductor device noise; signal processing equipment; sputter etching; 1 kHz; 1/f noise; CMOS electronic interface circuit; Si; Si fusion bonding; capacitive sensor interface; closed-loop force-balancing; deep RIE; deep reactive ion etching; dynamic range; force-balanced accelerometer; high aspect ratios; high sensitivity; hybrid approach; low cross-axis sensitivity; mG resolution; mechanical element; nonlinearity minimization; Accelerometers; Bandwidth; Bonding; Capacitive sensors; Dynamic range; Etching; Fabrication; Noise reduction; Prototypes; Silicon;
Conference_Titel :
Solid State Sensors and Actuators, 1997. TRANSDUCERS '97 Chicago., 1997 International Conference on
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-3829-4
DOI :
10.1109/SENSOR.1997.635447
