Wafer-level MEMS packaging via thermally released metal-organic membranes

Autor: Farrokh Ayazi, P. Monajemi, P.J. Joseph, Paul A. Kohl
Rok vydání: 2006
Předmět:
Zdroj: Journal of Micromechanics and Microengineering. 16:742-750
ISSN: 1361-6439
0960-1317
DOI: 10.1088/0960-1317/16/4/010
Popis: This paper reports on the design, implementation and characterization of wafer-level packaging technology for a wide range of microelectromechanical system (MEMS) devices. The encapsulation technique is based on thermal decomposition of a sacrificial polymer through a polymer overcoat to form a released thin-film organic membrane with scalable height on top of the active part of the MEMS. Hermiticity and vacuum operation are obtained by thin-film deposition of a metal such as chromium, aluminum or gold. The thickness of the overcoat can be optimized according to the size of the device and differential pressure to package a wide variety of MEMS such as resonators, accelerometers and gyroscopes. The key performance metrics of several batches of packaged devices do not degrade as a result of residues from the sacrificial polymer. A Q factor of 5000 at a resonant frequency of 2.5 MHz for the packaged resonator, and a static sensitivity of 2 pF g −1 for the packaged accelerometer were obtained. Cavities as small as 0.000 15 mm 3 for the resonator and as large as 1 mm 3 for the accelerometer have been made by this method. (Some figures in this article are in colour only in the electronic version)
Databáze: OpenAIRE
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