Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-05-11T03:51:37.088Z Has data issue: false hasContentIssue false

Solution Chemistry Optimization of Sol-Gel Processed Pzt Thin Films

Published online by Cambridge University Press:  21 February 2011

Steven J. Lockwood
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
R. W. Schwartz
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
B. A. Tuitle
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
E. V. Thomas
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
Get access

Abstract

We have optimized the ferroelectric properties and microstructural characteristics of sol-gel PZT thin films used in a CMOS-integrated, 256 bit ferroelectric non-volatile memory. The sol-gel process utilized in our work involved the reaction of Zr n-butoxide, Ti isopropoxide, and Pb (IV) acetate in a methanol/acetic acid solvent system. A 10-factor screening experiment identified solution concentration, acetic acid addition, and water volume as the solution chemistry factors having the most significant effects on the remanent polarization, coercive field, ferroelectric loop quality, and microstruntural quality. The optimal values for these factors were determined by runnig a 3-factor uniform shell design, modelling the responses, and testing the models at the predicted optimal conditions. The optimized solution chemistry generated 3-layer, 300-400 nm thick films on RuO2 coated silicon substrates with coercive fields of less than 25 kV/cm (a 40-50 % improvement over the original solution chemistry), a remanent polarization of 25-30 μC/cm, and a reduction in the pyrochlore phase content below observable levels.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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. Swartz, S. L., Bright, S. J., and Busch, J. R. in Ceramic Transactions 14, 159178 (1990).Google Scholar
2. Fukushima, J., Kodaira, K., and Matsushita, T., J. Mater. Sci., 19,595 (1984).Google Scholar
3. Vest, R. W. and Xu, J., Ferroelectrics, 93, 21 (1989).Google Scholar
4. Heartling, G. H., Ferroelectrics, 116, 51 (1991).Google Scholar
5. Schwartz, R. W., Bunker, B. C., Dimos, D. B., Assink, R. A., Tuttle, B. A., Tallant, D. R., and Weinstock, I. A., Integrated Ferroelectrics, 2, 243254 (1992).Google Scholar
6. Schwartz, R. W., Assink, R. A., and Headley, T. J. in Ferroelectric Thin Films II. edited by Kingon, A. I., Meyers, E. R., and Tuttle, B. A. (Mater. Res. Soc. Proc. 243, Pittsburgh, PA, 1992) pp. 245254.Google Scholar
7. Yi, G., Wu, Z., and Sayer, M., J. Appl. Phys., 64 (5), 2717 (1988).Google Scholar
8. Plackett, R. L. and Burman, J. P., Biometrika, 33, 305325 (1946).CrossRefGoogle Scholar
9. Doehlert, D. H., Appl. Stat., JRSS-C (1970).Google Scholar
10. Keefer, K. D. in Better Ceramics Through Chemistry, edited by Brinker, C. J., Clark, D. E., and Ulrich, D. R. (Mater. Res. Soc. Proc. 32, New York, NY, 1984) pp. 1524.Google Scholar
11. Budd, K. D., Dey, S. K., and Payne, D. A., Brit. Ceram. Soc. Proc., 36, 107 (1985).Google Scholar