Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-10T08:45:56.541Z Has data issue: false hasContentIssue false
  • English
  • Français

Selective W for Coating and Releasing MEMS Devices

Published online by Cambridge University Press:  10 February 2011

S. S. Mani ,
J. G. Fleming ,
J. J. Sniegowski ,
M. P. de Boer ,
L. W. Irwin ,
J. A. Walraven ,
D. M. Tanner  and
D. A. La Van
S. S. Mani
Affiliation:
MS 1084, PO Box 5800, Sandia National Laboratories, Albuquerque, NM 87185-1084, ssmani@sandia.gov
Get access

Abstract

Two major problems associated with Si-based MEMS (MicroElectroMechanical Systems) devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, we will present a CVD (Chemical Vapor Deposition) process that selectively coats MEMS devices with tungsten and significantly enhances device durability. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable. This selective deposition process results in a very conformal coating and can potentially address both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through the silicon reduction of WF6. The self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. The tungsten is deposited after the removal of the sacrificial oxides to minimize stress and process integration problems. Tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. The wear resistance of selectively coated W parts has been shown to be significantly improved on microengine test structures.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 605: Symposium MM – Materials Science of Microelectromechanical Systems Devices II , 1999 , 135
Copyright
Copyright © Materials Research Society 2000

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. Howe, R. T. and Muller, R. S., J. Electrochem Soc: Solid State Science & Technology, 103(6) p. 1420 (1983).Google Scholar
2. Garcia, E. J. and Sniegowski, J. J., Sensors and Actuators A, 48, p. 203 (1995).Google Scholar
3. Miller, S. L., Sniegowski, J. J., LaVigne, G., and McWhorter, P. J. in Proceedings of SPIE Smart Electronics and MEMS 2722, p. 197 (1996).Google Scholar
4.Danelle Tanner, M., Miller, W. M., Eaton, W. P., Irwin, L. W., Peterson, K. A., Dugger, M. T., Senft, D. C., Smith, N. F., Tangyunyong, P., and Miller, S. L. in 1998 IEEE International Reliability Physics Proceedings, p. 26 (1998).Google Scholar
5. Tanner, Danelle M., Walraven, Jeremy A., Irwin, Lloyd W., Dugger, Michael T., Smith, Norman F., Miller, William M., and Miller, Samuel L. in Proc. Of IEEE International Reliability Physics Symposium, p. 189 (1999).Google Scholar
6. Deng, K., Collins, R. J., Mehrengany, M. and Sukenik, C. N., J. Elctrochem. Soc., 142(4), p. 1278 (1995).Google Scholar
7. Srinivasan, U., Houston, M. R., Howe, R. T. and Maboudian, R., J. Micromech. Sys., 7(2), p. 252 (1998).10.1109/84.679393Google Scholar
8. Bradbury, D. R., Turner, J. E., Nauka, K. and Chiu, K. Y., IEDM, p. 273, (1991).Google Scholar
9. Sekine, M., Kakuhara, Y., Yamazaki, K. and Murao, Y., MRS Advanced Metallization ULSI Applications, p. 255, (1991).Google Scholar
10. Yu, M. L., Eldridge, B. N., and Joshi, R. V., in Deposition and Growth: Limits for Microelectronics, edited by Rubloff, G. W. (AIP Conf. Proc. 167, New York 1988), p. 202.Google Scholar
11. Broadbent, E. K. and Ramiller, C. L., J Elctrochem. Soc.: Solid-State Science and Techonolgy, 131(6), p. 1427 (1984).Google Scholar
12. Green, M. L and Levy, R. A., J Elctrochem. Soc.: Solid-State Science and Techonolgy, 132(5), p. 1243 (1985).Google Scholar
13. Yu, M. L., Eldridge, B. N., and Joshi, R. V., in Tungsten and Other Refractory Metals for VLSA Applications III, edited by Wells, V. A. (MRS Proc. Pittsburgh, PA), 1988, p. 75.Google Scholar
14. Kepten, A., Reisman, A., Ray, M., SMith, P. L., Temple, D., and Tapp, F., J. Electrochem. Soc, 139(8), p. 2331 (1992).Google Scholar
15. Mani, S. S., Fleming, J. G, and Sniegowski, J. J. in Proceedings of SPIE, Micromachining anc Microfabrication Process Technology V, 3874, p. 150 (1999).Google Scholar
16. Miller, S. L., Sniegowski, J. J., LaVigne, G., and McWhorter, P. J. in Proceedings of SPIE Micromachined Devices and Components II, 2882, p. 182 (1996).10.1117/12.250702Google Scholar
17. Smith, Norman F., Eaton, William P., Tanner, Danelle M., and Allen, James J. in SPIE Proceedings, 3880, p. 156 (1999).Google Scholar
18. Miller, S. L., Rodgers, M. S., LaVigne, G., Sniegowski, J. J., Clews, P., Tanner, D. M., Peterson, K. A. in Proc. Of IEEE International Reliability Physics Symposium, p. 17 (1998).Google Scholar
19. LaVan, D. A. and Buchheit, T. E. in Symposium MM Materials Science of MicroElectroMechanical System (MEMS) Devices 11, Proceedings of the 1999 MRS Fall Meeting Dec 1-3 1999 Boston.Google Scholar