Hostname: page-component-76fb5796d-dfsvx Total loading time: 0 Render date: 2024-04-27T00:26:23.648Z Has data issue: false hasContentIssue false

Fatigue Degradation of Nanometer-Scale Silicon Dioxide Reaction Layers on Silicon Structural Films

Published online by Cambridge University Press:  10 February 2011

C.L. Muhlstein
Affiliation:
Department of Materials Science and Engineering and the Materials Research Institute, The Pennsylvania State University, University Park, PA 16802
E.A. Stach
Affiliation:
National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
R.O. Ritchie
Affiliation:
Materials Sciences Division, Lawrence Berkeley National Laboratory, and Department of Materials Science and Engineering, University of California, Berkeley, CA 94720
Get access

Abstract

Although bulk silicon is ostensibly immune to cyclic fatigue and environmentally-assisted cracking, the thin film form of the material exhibits significantly different behavior. Such silicon thin films are used in small-scale structural applications, including microelectromechanical systems (MEMS), and display ‘metal-like’ stress-life (S/N) fatigue behavior in room temperature air environments. Fatigue lives in excess of 1011 cycles have been observed at high frequency (∼40 kHz), fully-reversed stress amplitudes as low as half the fracture strength using surface micromachined, resonant-loaded, fatigue characterization structures. Recent experiments have clarified the origin of the susceptibility of thin film silicon to fatigue failure. Stress-life fatigue, transmission electron microscopy, infrared microscopy, and numerical models have been used to establish that the mechanism of the apparent fatigue failure of thin-film silicon involves sequential oxidation and environmentally-assisted crack growth solely within the nanometerscale silica layer on the surface of the silicon, via a process that we term ‘reaction-layer fatigue’. Only thin films are susceptible to such a failure mechanism because the critical crack size for catastrophic failure of the entire silicon structure can be exceeded by a crack solely within the surface oxide layer. The growth of the oxide layer and the environmentally-assisted initiation of cracks under cyclic loading conditions are discussed in detail. Furthermore, the importance of interfacial fracture mechanics solutions and the synergism of the oxidation and cracking processes are described. Finally, the successful mitigation of reaction-layer fatigue with monolayer coatings is shown.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Allameh, S.M., Gally, B., Brown, S. and Soboyejo, W.O., in Mechanical Properties of Structural Films, STP 1412 Muhlstein, C., and Brown, S., eds. (American Society for Testing and Materials, West Conshohocken, PA, 2001), vol. 1413, pp. 316.Google Scholar
2. Bagdahn, J. and Sharpe, W.N.J., in MEMS 2002, IEEE, 2002, pp. 447450.Google Scholar
3. Brown, S.B., Van Arsdell, W. and Muhlstein, C.L., in Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97), edited by Senturia, S., IEEE, 1997, pp. 591–93.Google Scholar
4. Connally, J.A. and Brown, S.B., Science, 256, 1537–39 (1992).Google Scholar
5. Kahn, H., Ballarini, R., Mullen, R.L. and Heuer, A.H., Proc. Roy. Soc. A, 455, 3807–23 (1999).Google Scholar
6. Kapels, H., Aigner, R. and Binder, J., in Proceedings of the 29th European Solid-State Device Research Conference, edited, IEEE, 1999, pp. 1522–28.Google Scholar
7. Komai, K., Minoshima, K. and Inoue, S., Micros. Tech., 5, 3037 (1998).Google Scholar
8. Muhlstein, C.L., Brown, S.B. and Ritchie, R.O., J. Microelectromech. Sys., 10, 593600 (2001).Google Scholar
9. Muhlstein, C.L., Brown, S.B. and Ritchie, R.O., Sens. Actuators A, 94, 177–88 (2001).Google Scholar
10. Muhlstein, C.L., Stach, E.A. and Ritchie, R.O., Appl. Phys. Let., 80, 15321534 (2002).Google Scholar
11. Muhlstein, C.L., Stach, E.A. and Ritchie, R.O., Acta Mater., 50, 35793595 (2002).Google Scholar
12. Simmons, G. and Wang, H., Single Crystal Elastic Constants and Calculated Aggregate Properties: a Handbook, 2nd ed., Press, M.I.T., Cambridge, MA, 1971.Google Scholar
13. Broek, D., Elementary engineering fracture mechanics, 4th ed., Martinus Nijhoff; Distributed by Kluwer, Dordrecht; Boston: Hingham, MA, 1986.Google Scholar
14. Anderson, T.L., Fracture mechanics: Fundamentals and Applications, 2nd ed., edited by, CRC Press, Boca Raton, 1995.Google Scholar