TY - JOUR
TI - On the influence of environment gases, relative humidity and gas
purification on dielectric charging/discharging processes in
electrostatically driven MEMS/NEMS devices
AU - Zaghloul, U.
AU - Bhushan, B.
AU - Pons, P.
AU - Papaioannou, G. J. and
AU - Coccetti, F.
AU - Plana, R.
JO - Nanotechnology Perceptions
PY - 2011
VL - 22
TODO - 3
SP - null
PB - IOP Publishing Ltd
SN - null
TODO - 10.1088/0957-4484/22/3/035705
TODO - null
TODO - In this paper, we investigate the impact of environment gases and
relative humidity on dielectric charging phenomenon in electrostatically
actuated micro- and nano-electromechanical systems (MEMS and NEMS). The
research is based on surface potential measurements using Kelvin probe
force microscopy (KPFM). Plasma-enhanced chemical vapor deposition
(PECVD) silicon nitride films were investigated in view of applications
in electrostatic capacitive RF MEMS switches. Charges were injected
through the atomic force microscope (AFM) tip, and the induced surface
potential was measured using KPFM. Experiments have been performed in
air and in nitrogen environments, both under different relative humidity
levels ranging from 0.02% to 40%. The impact of oxygen gas and
hydrocarbon contaminants has been studied for the first time by using
different gas purifiers in both air and nitrogen lines. Voltage pulses
with different bias amplitudes have been applied during the charge
injection step under all investigated environmental conditions in order
to investigate the effect of bias amplitude. The investigation reveals a
deeper understanding of charging and discharging processes and could
further lead to improved operating environment conditions in order to
minimize the dielectric charging. Finally, the nanoscale KPFM results
obtained in this study show a good correlation with the device level
measurements for capacitive MEMS switches reported in the literature.
ER -