Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-23T12:06:48.587Z Has data issue: false hasContentIssue false

Development of PECVD SiC for MEMS Using 3MS as the Precursor

Published online by Cambridge University Press:  01 February 2011

Neha Singh
Affiliation:
[email protected], Case Western Reserve University, Department of Electrical Engineering and Computer Science, Glennan Bld. 10900 Euclid Ave., Cleveland, OH, 44106, United States
James B. Summers
Affiliation:
[email protected], Case Western Reserve University, Department of Electrical Engineering and Computer Science, Glennan Bld. 10900 Euclid Ave., Cleveland, OH, 44106, United States
Christian A. Zorman
Affiliation:
[email protected], Case Western Reserve University, Department of Electrical Engineering and Computer Science, Glennan Bld. 10900 Euclid Ave., Cleveland, OH, 44106, United States
Get access

Abstract

This paper reports our effort to develop amorphous hydrogenated silicon carbide (a-SiC:H ) films specifically designed for MEMS applications using a semiconductor-grade organosilane known as trimethylsilane (3MS) as the precursor. In our work, the a-SiC:H films were deposited in a commercial PECVD system at a fixed temperature of 350˚C using 3MS diluted in helium (He). Films with thicknesses from ~ 100 nm to ~ 2μm, a typical range for MEMS applications, were deposited. Deposition parameters such RF power, deposition pressure, and 3MS-to-He ratio were explored to obtain films with low residual compressive stresses. Low temperature, post-deposition annealing at 450˚C was used to convert the as-deposited compressive residual stresses to moderate tensile stresses, which are desired for micromachined bridges, membranes and other anchored structures. Compositional analysis indicated that films with a Si-to-C ratio of 1 could be deposited under certain conditions. Mechanical properties such as Young's modulus and fracture strength were derived from the load-deflection behavior of micromachined freestanding membranes. Nanoindentation was used to verify the Young's modulus and determine the hardness. As expected, the films exhibit insulating properties with a relative dielectric constant at 3.90 for as-deposited films and 2.69 after annealing at 1100˚C, as determined from C-V measurements. Chemical inertness was tested in aqueous, corrosive solutions such as KOH and HNA. Prototype structures were fabricated using both surface micromachining and bulk micromachining techniques to demonstrate the potential of the a-SiC:H films for MEMS applications.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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 Mehregany, M., Zorman, C. A., Rajan, N., and Wu, C. H., Proceedings of the IEEE 86, 15941609 (1998).Google Scholar
2 Zorman, C. A., Fleischman, A. J., Dewa, A. S., Mehregany, M., Jacob, C., Nishino, S., and Pirouz, P., Journal of Applied Physics 78, 51365138 (1995).Google Scholar
3 Fu, X.-A., Dunning, J. L., Zorman, C. A., and Mehregany, M., Sensors and Actuators A (Physical) 119, 169–76 (2005).Google Scholar
4 Cogan, S. F., Edell, D. J., Guzelian, A. A., Liu, Y. P., and Edell, R., Journal of Biomedical Materials Research - Part A 67, 856867 (2003).Google Scholar
5 Berthold, A., Laugere, F., Schellevis, H., Boer, C. R. de, Laros, M., Guijt, R. M., Sarro, P. M., and Vellekoop, M. J., Electrophoresis 23, 3511–19 (2002).Google Scholar
6 Bagolini, A., Pakula, L., Scholtes, T. L. M., Pham, H. T. M., French, P. J., and Sarro, P. M., Journal of Micromechanics and Microengineering 12, 385389 (2002).Google Scholar
7 Zhang, W., Lelogeais, M., and Ducarroir, M., Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes 31, 40534060 (1992).Google Scholar
8 Loboda, M. J., Microelectronic Engineering 50, 1523 (2000).Google Scholar
9 Sarro, P. M., Transducers '99: 10th International Conference on Solid State Sensors and Actuators A82, 210–18 (2000).Google Scholar
10 Pakula, L. S., Yang, H., Pham, H. T. M., French, P. J., and Sarro, P. M., Proceedings of the IEEE Micro Electro Mechanical Systems (MEMS), 502–505 (2003).Google Scholar
11 Loboda, M. J., Seifferly, J. A., Grove, C. M., and Schneider, R. F., Materials Research Society Symposium Proceedings 447, 145150 (1997).Google Scholar
12 Fu, X.-a., Dunning, J. L., Zorman, C. A., and Mehregany, M., Thin Solid Films 492, 195202 (2005).Google Scholar
13 Kaushik, A., Kahn, H., and Heuer, A. H., Journal of Microelectromechanical Systems 14, 359–67 (2005).Google Scholar