Contact resistance in flat thin films
MEMS-fabricated electrical contacts are commonly used in MEMS relays. These electrical contacts can be as simple as two flat surfaces coming into contact [1]. Modeling their contact force/resistance relationship can be difficult because much of the theory on contact resistance was developed for...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Institute of Electrical and Electronics Engineers
2010
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| Online Access: | http://hdl.handle.net/1721.1/60268 https://orcid.org/0000-0002-5048-4109 https://orcid.org/0000-0002-5765-4369 |
| Summary: | MEMS-fabricated electrical contacts are commonly
used in MEMS relays. These electrical contacts can be as simple
as two flat surfaces coming into contact [1]. Modeling their
contact force/resistance relationship can be difficult because
much of the theory on contact resistance was developed for
macro-scale contacts [2], and contact properties for MEMS-scale
contacts do not always agree with those predicted by this theory
[3]. One contribution to this disagreement is that when the
dimensions of the contact thickness are on the order of the a-spot
dimensions, the spreading resistance is affected [4]. In order to
determine the relationship between contact force and resistance
for a wide range of parameters, we have developed a two-coupon
test system which allows the properties of these contacts to be
empirically determined. The design of the two-coupon system
allows for the rapid fabrication of multiple contact materials and
geometries. The two-coupon system was used to test the contact
resistance properties of sputtered and electroplated Au films in
thicknesses of 0.1 μm, 0.3 μm, and 0.5 μm. Contact force was
measured using a custom flexural force gauge and the 4-point
contact resistance was measured using an integrated Kelvin
Structure [5]. The results are compared to traditional Holm
theory to determine the effects of film thickness on spreading
resistance. |
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