We demonstrate softening of the gold-to-gold contact in surface micromachined microelectromechanical switches under electrostatic force near , which results from the heating of contact asperities sustaining electron transport. A bias potential that causes the switch contacts to soften is measured for initial contact resistance varying between 0.5 and . The asperity sizes in this range are comparable to the electron mean-free path at room temperature. We show that contact spots smaller than the mean-free path require larger bias for softening. Our results can be explained using a model accounting for ballistic electron transport in the contact.
Low-force contact heating and softening using micromechanical switches in diffusive-ballistic electron-transport transition
Brian D. Jensen, Kuangwei Huang, Linda L.-W. Chow, Katsuo Kurabayashi; Low-force contact heating and softening using micromechanical switches in diffusive-ballistic electron-transport transition. Appl. Phys. Lett. 10 January 2005; 86 (2): 023507. https://doi.org/10.1063/1.1850191
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