Low-temperature thin-film silicon MEMS

This paper presents fabrication of microelectromechanical systems (MEMS) at low temperatures (100 degreesC) using thin film silicon technology and their electromechanical characterization. Thin film technology can enable the expansion of MEMS to applications requiring low-temperature fabrication on a CMOS backplane, or on large area and/or flexible substrates. Electrostatic actuation, both in a quasi-DC regime and at the resonance frequency range, of bridge and cantilever structures on glass substrates is described. The resulting movement of the microstructures is characterized using optical, and integrated magnetic and piezoresistive detection. In the quasi-DC regime, control of the actuation of the structures to deflections on the sub-nanometer scale is achieved. Resonance frequencies up to 22 MHz have been measured on hydrogenated amorphous silicon bridges with quality factors up to 100 in air. (C) 2002 Elsevier Science B.V. All rights reserved.