Abstract
Microcantilever beams are frequently utilized as sensor platforms in microelectromechanical system devices. These highly compliant surface-micromachined structures generally fail by adhering to the underlying substrate during processing or subsequent operation. Such failures, which are commonly known as "stiction" failures, can be prevented or repaired in a number of ways, including low adhesion coatings, rinsing with low surface energy agents, and active approaches such as laser irradiation. Gupta et al. [J. Microelectromech. Syst. vol. 13, pp. 696-700, 2004] recently demonstrated that stress waves could be used to repair stiction-failed structures. This paper extends the work of Gupta et al. by developing a fracture mechanics theory of the repair process and compares that theory with corresponding experiments. We show that: 1) incremental crack growth is associated with each laser pulse, the extent of which is directly related to the laser fluence; 2) repeated pulsing fully repairs all of the microcantilevers; and 3) a fracture mechanics model accurately predicts the observed experimental results.
| Original language | English |
|---|---|
| Pages (from-to) | 904-911 |
| Number of pages | 8 |
| Journal | Journal of Microelectromechanical Systems |
| Volume | 16 |
| Issue number | 4 |
| DOIs | |
| State | Published - Aug 2007 |
| Externally published | Yes |
Bibliographical note
Funding Information:Manuscript received July 23, 2005; revised April 5, 2006. This work was supported in part by the National Science Foundation through the Small Grants for Exploratory Research under Grant 0240020 and in part by the U.S. Department of Energy under Grant DEFG02-91-ER45439 to the Center for Microanalysis of Materials, University of Illinois, where part of this work was carried out. Subject Editor C. Mastrangelo.
Keywords
- Fracture mechanics
- Laser
- Stiction
- Stress waves
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering