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Wet-Etch Patterning of Lead Zirconate Titanate (PZT) Thick Films for Microelectromechanical Systems (MEMS) Applications

Published online by Cambridge University Press:  17 March 2011

L.-P. Wang
Affiliation:
The Penn State University, University Park, PA16802
R. Wolf
Affiliation:
The Penn State University, University Park, PA16802
Q. Zhou
Affiliation:
The Penn State University, University Park, PA16802
S. Trolier-McKinstry
Affiliation:
The Penn State University, University Park, PA16802
R. J. Davis
Affiliation:
Triquint Semiconductor, 13512 N. Central Expressway, Dallas, TX75243
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Abstract

Lead zirconate titanate (PZT) films are very attractive for microelectromechanical systems (MEMS) applications because of their high piezoelectric coefficients and good electromechanical coupling. In this work, wet-etch patterning of sol-gel PZT films for MEMS applications, typically with film thicknesses ranging from 2 to 10 microns, was studied. A two- step wet-etch process was developed. In the first step, 10:1 buffered HF is used to remove the majority of the film at room temperature. Then a solution of 2HCl:H2O at 45°C is used to remove metal-fluoride residues remaining from the first step. This enabled successful patterning of PZT films up to 8 microns thick. A high etch rate (0.13μm/min), high selectivity with respect to photoresist, and limited undercutting (2:1 lateral:thickness) were obtained. The processed PZT films have a relative permittivity of 1000, dielectric loss of 1.6%, remanent polarization (Pr) of 24μC/cm2, and coercive field (Ec) of 42.1kV/cm, all similar to those of unpatterned films of the same thickness.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1. Najafi, K., VLSI Circuits, Digest of Technical Papers, 6, (2000).Google Scholar
2. Pottenger, M., Eyre, B., Kruglick, E., and Lin, G., Solid State Technology, 40 (9), 89, (1997).Google Scholar
3. Eddy, D. S. and Sparks, D. R., Proceedings of The IEEE, 86 (8), 9 (1998).Google Scholar
4. Mollendorf, M., Proceedings of ASME Aerospace Division, 52, 761 (1996).Google Scholar
5. Evans, J. T. and Wormack, R., IEEE J. Solid-State Circuits, 23, 1171 (1988).Google Scholar
6. Hendrickson, M., Su, T., Trolier-McKinstry, S., Rod, B. J., and Zeto, R. J., 10th IEEE International Symposium on Applications of Ferroelectrics, Part 2, 2, 683 (1996).Google Scholar
7. Zhang, Q. M., Wang, H., Kim, N., and Cross, L. E., J. Applied Physics, 75 (1), 454 (1994).Google Scholar
8. Saito, K., Choi, J. H., Fukuda, T., and Ohue, M., Jpn. J. Applied Physics, 31, 1260 (1992).Google Scholar
9. Kim, C. J., Lee, J. K., Chung, C. W., Chung, I., Integrated Ferroelectrics Proceedings of Technology, 16 (1-4), 149 (1997).Google Scholar
10. Yokoyama, S., Ito, Y., Ishihara, K., Hamada, K., Ohnishi, S., Kudo, J., and Sakiyama, K., Jpn. J. Applied Physics, 34, 767 (1995).Google Scholar
11. Fox, G. R., Trolier-McKinstry, S., and Krupanidhi, S. B., J. Mater. Res., 10 (6), 1508 (1995).Google Scholar
12. Zhou, Q. F., Hong, F., Wolf, R., and Trolier-McKinstry, S., Materials Research Society Symposium Proceedings, 2000 Fall Meeting (in press)Google Scholar
13. Trolier, S. E., M.S. Thesis 1987i, The Pennsylvania University (1987).Google Scholar
14. Wang, L.-P. et al. , manuscript in preparation for submission to J. Microelectromechanical Systems. Google Scholar