DocumentCode :
1533098
Title :
Device-Level Vacuum Packaging for RF MEMS
Author :
Rahman, M. Shahriar ; Chitteboyina, Murali M. ; Butler, Donald P. ; Çelik-Butler, Zeynep ; Pacheco, Sergio P. ; McBean, Ronald V.
Author_Institution :
Dept. of Electr. Eng., Univ. of Texas at Arlington, Arlington, TX, USA
Volume :
19
Issue :
4
fYear :
2010
Firstpage :
911
Lastpage :
918
Abstract :
For specific RF applications, where the use of MEMS is highly attractive, cost-effective reliable packaging is one of the primary barriers to commercialization. Many RF MEMS devices require a hermetic or vacuum operation environment. This paper presents a post-CMOS-compatible method for vacuum packaging of RF MEMS devices by growing an encapsulation layer during the device fabrication. The resulting MEMS devices are surrounded by a vacuum cavity and can then be placed in a conventional low-cost circuit package. This is a low-temperature area-efficient device-level encapsulation for MEMS devices. RF MEMS resonators in a fixed-fixed configuration were used as the test bed since their quality factor can be used as a measure of the package quality. The encapsulation process is based on a double-sacrificial-layer surface micromachining technique, which is used to create a cavity under and above the resonator. Polyimide was used as the sacrificial layer, followed by the deposition of a packaging layer with trench cuts, which facilitate the sacrificial layer removal. The trench cuts were then sealed at a low pressure, forming a cavity around the device at the sealant layer deposition pressure. Extensive RF characterization and reliability tests were performed on the packaged resonators.
Keywords :
CMOS integrated circuits; encapsulation; integrated circuit packaging; micromachining; micromechanical resonators; radiofrequency integrated circuits; CMOS-compatible method; RF MEMS device fabrication; RF MEMS resonators; device-level vacuum packaging; double-sacrificial-layer surface micromachining technique; encapsulation layer; low-cost circuit packaging; polyimide; quality factor; sealant layer deposition pressure; Alumina; RF-MEMS; device-level packaging; encapsulation; packaging; reliability;
fLanguage :
English
Journal_Title :
Microelectromechanical Systems, Journal of
Publisher :
ieee
ISSN :
1057-7157
Type :
jour
DOI :
10.1109/JMEMS.2010.2055541
Filename :
5508328
Link To Document :
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