Skip to main content Accessibility help
×
Home

An Experimental Examination of Mems Microactuator Material Issues

  • T. G. Cooney (a1), D. E. Glumac (a1), W. P. Robbins (a2) and L. F. Francis (a1)

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.

Copyright

References

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

An Experimental Examination of Mems Microactuator Material Issues

  • T. G. Cooney (a1), D. E. Glumac (a1), W. P. Robbins (a2) and L. F. Francis (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed