Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-05-05T16:01:51.264Z Has data issue: false hasContentIssue false

Mechanical Characterization of Thin-Film Composites using the Load-Deflection Response of Multilayer Membranes - Elastic and Fracture Properties

Published online by Cambridge University Press:  26 February 2011

Joao Gaspar
Affiliation:
gaspar@imtek.de, University of Freiburg, Department of Microsystems Engineering (IMTEK), Microsystems Materials Laboratory, Georges-Koehler-Allee 103, Freiburg, 79110, Germany, +497612037194, +497612037192
Patrick Ruther
Affiliation:
ruther@imtek.de, University of Freiburg, Department of Microsystems Engineering (IMTEK), Microsystems Materials Laboratory, Georges-Koehler-Allee 103, Freiburg, 79110, Germany
Oliver Paul
Affiliation:
paul@imtek.de, University of Freiburg, Department of Microsystems Engineering (IMTEK), Microsystems Materials Laboratory, Georges-Koehler-Allee 103, Freiburg, 79110, Germany
Get access

Abstract

This paper reports on the refinement of a mechanical model for the load-deflection of multilayer membranes under uniform differential pressure and on its application to the experimental extraction of material parameters. Going beyond previous results, the analytical model takes into account the mechanics of multilayers and elastic supports covering all cases between rigidly clamped to simply supported structures and enables the straightforward assessment of stress profiles within the deformed structures. A comprehensive set of long membranes made of various multilayers of silicon nitride and oxide films are fabricated and characterized. The out-of-plane deflection profile under pressure load is monitored by means of a laser profilometer. The pressure is stepped up until fracture occurs. From the stress profiles in the membrane at fracture, the brittle material strength is analyzed using Weibull statistics. The bulge setup has been fully automated for the measurement of 80 membranes per wafer. This realizes, for the first time, the high throughput-acquisition of mechanical thin film data with convincing statistical control.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

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. Bromley, E. I., Randall, J., Flanders, D., Mountain, R., J. Vac. Sci. Technol. B 1, 1364 (1983).Google Scholar
2. Ziebart, V., Paul, O., Münch, U., Schwizer, J., Baltes, H., J. Microelectrom. Syst. 7, 320 (1998).Google Scholar
3. Paul, O. and Ruther, P., “Material Characterization,” chapter 2 in CMOS – MEMS, Advanced Micro & Nanosystems Series, vol. 2, ed. Brand, O., and Fedder, G. K. (Wiley-VCH, 2005).Google Scholar
4. Kramer, T., and Paul, O., IEEE MEMS Conf. Proc. 2003, 678 (2003).Google Scholar
5. Ziebart, V., Paul, O., and Baltes, H., J. Microelectromech. Syst. 8, 423 (1999).Google Scholar
6. Paul, O., and Baltes, H., J. Micromech. Microeng. 9, 19 (1999).Google Scholar
7. Weibull, W., J. Appl. Mech. 18, 293 (1951).Google Scholar
8. Davies, D. G. S., Proc. Brit. Ceramic Soc. 22, 429 (1973).Google Scholar
9. Vlassak, J. J., J. Mater. Res. 7, 3242 (1992).Google Scholar
10. Novozhilov, V. V., Foundations of the Nonlinear Theory of Elasticity (Dover, 1953).Google Scholar
11. Gerlach, G., Schroth, A., and Pertsch, P., Sens. Mater. 8, 79 (1996).Google Scholar
12. Timoshenko, S. and Krieger, S. W.-, Theory of Plates and Shells (McGraw-Hill, 1987).Google Scholar
13. Landau, L. and Lifshitz, E. M., Theory of Elasticity (Pergamon, Oxford UK, 1986).Google Scholar
14. Yang, J., and Paul, O., Sens. Actuators A 9798, 520 (2002).Google Scholar
15. Gaspar, J., Ruther, P., Paul, O., Proc. 3rdInt. Conf. Multiscale Materials Modeling, 966 (2006).Google Scholar
16. Rasmussen, F. et al. , Proc. Int. Symp. Sci. Tech. Dielectrics in Emerging Fields, 218 (2003).Google Scholar
17. Cardinale, G. F., and Tustison, R. W., Thin Solid Films 207, 126 (1992).Google Scholar