Institute of Electrical and Electronic Engineers (IEEE)
2009 Proceedings of the 55th IEEE Holm Conference on Electrical Contacts
This paper reports on an improved analytic model for predicting micro-contact resistance needed for designing microelectro-mechanical systems (MEMS) switches. The original model had two primary considerations: 1) contact material deformation (i.e. elastic, plastic, or elastic-plastic) and 2) effective contact area radius. The model also assumed that individual aspots were close together and that their interactions were dependent on each other which led to using the single effective aspot contact area model. This single effective area model was used to determine specific electron transport regions (i.e. ballistic, quasi-ballistic, or diffusive) by comparing the effective radius and the mean free path of an electron. Using this model required that micro-switch contact materials be deposited, during device fabrication, with processes ensuring low surface roughness values (i.e. sputtered films). Sputtered thin film electric contacts, however, do not behave like bulk materials and the effects of thin film contacts and spreading resistance must be considered. The improved micro-contact resistance model accounts for the two primary considerations above, as well as, using thin film, sputtered, electric contacts.