Abstract
High aspect ratio nickel radio frequency microelectromechanical systems (RF MEMS) were fabricated by X-ray lithography and electroplating. Control of growth during electroforming of micro components is in general a problem in terms of achieving homogeneous thickness due to a non-uniform current distribution across a layout. It is necessary to level the deposited layer by means of a lapping process which results in burr formation. To ensure the functional properties of the devices these burrs have to be removed. Electropolishing with a current density of 80 A/dm2 is used for burr removal from nickel micro components containing small width (~10 μm) structural elements. The investigated metal removal rates range from 0.2 to 1.8 μm/s depending on burr formation, presence or absence of resist and device position in the layout during electropolishing. Furthermore, edge rounding, a common electropolishing effect, is only observed when electropolishing in the absence of resist.
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Acknowledgments
The authors would like to thank Mr. Paul Abaffy (Institute of Microstructure Technology, KIT) for taking the SEM images and Mr. Günter Beuchle (Institute for Technical Chemistry, KIT) for taking the ESEM images.
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Kissling, S., Bade, K., Börner, M. et al. Electropolishing as a method for deburring high aspect ratio nickel RF MEMS. Microsyst Technol 16, 1361–1367 (2010). https://doi.org/10.1007/s00542-010-1075-z
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DOI: https://doi.org/10.1007/s00542-010-1075-z