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

Volume

58

Issue

12

fYear

2010

Firstpage

3961

Lastpage

3970

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;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2010.2086069

Filename

5624624