Title :
Piezoresistive Position Sensing for the Detection of Hysteresis and Dielectric Charging in CMOS-MEMS Variable Capacitors
Author :
Zahirovic, Nino ; Mansour, Raafat R. ; Yu, Ming
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Waterloo, Waterloo, ON, Canada
Abstract :
μA position sensing scheme for the detection of hysteresis and dielectric charging is presented. The sensing mechanism is based upon piezoresistance and is applied to an RF MEMS variable capacitor fabricated using a standard 0.35 μm CMOS process with MEMS postprocessing. The position sensor, based upon the piezoresistive property of the CMOS polysilicon layer, proves capable of detecting the effects of hysteresis and dielectric charging in the fabricated device. Potential applications of the sensing scheme include the mitigation of the effects of hysteresis and dielectric charging on MEMS variable capacitors through closed-loop control.
Keywords :
CMOS integrated circuits; capacitors; microsensors; piezoresistive devices; μA position sensing scheme; CMOS polysilicon layer; CMOS-MEMS variable capacitors; MEMS postprocessing; RF MEMS variable capacitor; closed-loop control; dielectric charging; hysteresis detection; piezoresistive position sensing; position sensor; size 0.35 mum; Capacitors; Metals; Micromechanical devices; Piezoresistance; Radio frequency; Sensors; MEMS components and techniques; MEMS for multifunctional wireless communications systems; MEMS reliability; Microelectromechanical systems (MEMS); microsensors; tunable microwave circuits;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2010.2086069
