Film Stress Influence of Bilayer Metallization on the Structure of RF MEMS Switches
Abstract
The performance of microelectromechanical systems (MEMS) switches is highly dependent on the switches' constituent materials. The switch material must be able to provide both structural integrity and high electrical conductivity. Cantilever beams, doubly clamped beams, and membranes are typical MEMS structures used in microwave/millimeter wave applications. In this study, cantilever and doubly clamped beam microswitches were fabricated on GaAs substrates using evaporated bilayers of titanium and gold metallization in which the total thickness was held constant at 1.5 μm while the gold thickness varied from 0.5 μm to 1.5 μm. The lengths of the cantilevers varied from 300 to 500 μm and the doubly clamped beams varied from 600 to 800 μm. An upward deflection of the gold dominated cantilever beams indicated an increasing tensile stress gradient. Results of microwave characterization demonstrated higher switch isolation (off-resistance) for shorter beam switches at the expense of higher insertion loss (on-resistance) and actuation voltage. A discussion of the observed released microswitch structure within the context of the measured film stresses and electrical performance will be presented.
Recommended Citation
R. E. Strawser et al., "Film Stress Influence of Bilayer Metallization on the Structure of RF MEMS Switches," Materials Research Society Symposium - Proceedings, vol. 594, pp. 213 - 218, Materials Research Society, Dec 2000.
Department(s)
Materials Science and Engineering
International Standard Serial Number (ISSN)
0272-9172
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Materials Research Society, All rights reserved.
Publication Date
11 Dec 2000