%0 Journal Article %J (IOP) Journal of Micromechanics and Microengineering %D 2005 %T Measuring and interpreting the mechanical-thermal noise spectrum in a MEMS %A Rocha, L A %A Cretu, E %A Wolffenbuttel, R F %P S30-S38 %U http://www.iop.org/EJ/abstract/-search=24199841.2/0960-1317/15/7/005 %V 15 %X Measuring and interpreting the mechanical_thermal noise spectrum in a MEMS L A Rocha et al 2005 J. Micromech. Microeng. 15 S30-S38 doi:10.1088/0960-1317/15/7/005 PDF (525 KB) | References L A Rocha1, E Cretu2 and R F Wolffenbuttel1 1 Department for Microelectronics, Faculty of EEMCS, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands 2 Melexis, Transportstr. 1, Tessenderlo, Belgium Abstract. The meta-stability of the pull-in displacement of an electrostatically operated parallel plate micromechanical structure is used for the capacitive measurement of the mechanical_thermal noise spectrum in a MEMS. Pull-in time depends on force and is not affected by the input-referred noise of the readout circuit. Repeatedly bringing the microstructure to pull-in while measuring the pull-in time followed by FFT enables the measurement of the mechanical noise spectrum with a non-mechanical noise level set primarily by the resolution of the time measurement. The white noise level is found to be in agreement with the theory on damping. The 1/f noise spectrum is found to be independent of ambient gas pressure with a 1/f noise_white noise cross-over frequency at 0.007 Hz for a 1 bar gas pressure and is reproducible for devices fabricated in the same process and the same run. Print publication: Issue 7 (July 2005) Received 26 November 2004, in final form 28 February 2005 Published 20 June 2005 %8 July %9 article