Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-25T17:28:38.030Z Has data issue: false hasContentIssue false
  • English
  • Français

An Experimental Examination of Mems Microactuator Material Issues

Published online by Cambridge University Press:  16 February 2011

T. G. Cooney ,
D. E. Glumac ,
W. P. Robbins  and
L. F. Francis
T. G. Cooney
Affiliation:
Department of Chemical Engineering and Materials Science University of Minnesota, Minneapolis, MN 55455-0132
D. E. Glumac
Affiliation:
Department of Chemical Engineering and Materials Science University of Minnesota, Minneapolis, MN 55455-0132
W. P. Robbins
Affiliation:
Deparment of Electrical Engineering University of Minnesota, Minneapolis, MN 55455-0132
L. F. Francis
Affiliation:
Department of Chemical Engineering and Materials Science University of Minnesota, Minneapolis, MN 55455-0132
Get access

Abstract

Thermally induced interactions between materials in complex microactuator structures were investigated. The device structure contained a combination of a piezoelectric layer (lead zirconate titanate - PZT) an electrode with adhesion layer (Pt/Ti), buffer layer (SiO2 or TiO2), structural material (polysilicon and/or silicon nitride), and sacrificial oxide (SiO2). The presence of a SiO2 sacrificial layer did not affect either the bottom electrode or PZT layer. XRD results showed significant platinum and titanium silicide formation in the Pt/Ti electrode at 700 °C (PZT crystallization temperature) on both polysilicon and silicon nitride structural materials when no buffer layer was used. Auger analysis shows that the Ti adhesion layer oxidizes, that measured levels of silicon increase in the electrode zone, and that electrode elements diffuse into the structural material. Buffer layers of SiO2 (0, 0.1, 0.73, 1.3, 1.5 μm) and amorphous TiO2 (0.065 μm) were inserted between the electrode and the structural material. XRD and sheet resistance measurements demonstrated that SiO2 thicknesses greater than 0.73 μm reduced pyrochlore formation in the PZT and reduced the degradation of the electrode. However, this thickness was incompatible with overall surface micromachining processes. The TiO2 layer effectively prevented pyrochlore formation and electrode degradation, while being compatible with overall actuator processing.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 360 , 1994 , 401
Copyright
Copyright © Materials Research Society 1995

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

references

1.Sreenivas, K., Reaney, I. R., Maeder, T., Setter, N., Jagadish, C., and Elliman, R. G., J. Appl. Phys. 75 (1), 232 (1994).Google Scholar
2.Olowolafe, J. C., Jones, R. E., Campbell, A. C., Maniar, P. D., Hegde, R. I., and Mogab, C. J.Mat. Res. Soc. Proc. 243, 355, (1992).Google Scholar
3.Morgan, A. E., Broadbent, E. K., Ritz, K. N., Sadana, D. K., and Burrow, B. J., J. Appl. Phys 64 (1), 344 (1988).Google Scholar
4.Bender, H., Chen, W. D., Portillo, J, Hove, L. Van Den, and Vandervorst, W., Applied Surface Science 38, 37 (1989).Google Scholar
5.Meyers, S. A., and Meyers, E. R., Mat. Res. Soc. Proc. 243, 107 (1992).Google Scholar
6.Kim, C. J., Yoon, D. S., Lee, J. S., Choi, C. G., and No, K., Jpn. J. Appl. Phys. 33, 2675 (1994).Google Scholar
7.Glumac, D. E., Polla, D. L., Robbins, W. P., IEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 38 (5) (1991).Google Scholar
8.Glumac, D. E., Cooney, T. G., Francis, L. F., and Robbins, W. P., “Theoretical Predictions of Piezoelectric Microactuator Responses”, this proceedings.Google Scholar
9.Murarka, S. P., Peckerar, M. C., Electronic Materials: Science and Technology (Academic Press, Inc., New York, 1989).Google Scholar
10.Cooney, T. G., Hachfeld, E. A., and Francis, L. F., Ceramic Transactions 43, 197 (1994).Google Scholar
11.Wright, J. S., and Francis, L. F., J. Mat. Res. 8 (7), 1712 (1993).Google Scholar
12.Hsueh, C. C., and Mecartney, M. L., J. Mat. Res. 6 (10), 2208 (1991).Google Scholar