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Polarity and Area Dependence of Reliability Characteristics of Sputitered and Sol-Gel Derived Thin Plzt Films for Dram Applications

Published online by Cambridge University Press:  25 February 2011

C. Sudhama
Affiliation:
Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712
J. Kim
Affiliation:
Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712
V. Chikarmane
Affiliation:
Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712
J. C. Lee
Affiliation:
Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712
A. F. Tasch
Affiliation:
Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712
E. R. Myers
Affiliation:
National Semiconductor Corp., Santa Clara, CA 95052
S. Novak
Affiliation:
Evans East Inc., Plainsboro, NJ 08536
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Abstract

The reliability properties of sputtered and sol-gel derived lanthanum doped lead-zirconatetitanate (Pb1-xLax(Zr,Ti)O3) have been studied for DRAM applications. A strong polarity dependence for times-to-breakdown (tbd) and significant space charge effects are observed under constant voltage stressing, and are understood to be related to the movement of oxygen vacancies in the d.c. field. The equilibrium current density attained during d.c. stressing appears to be Schottky emission limited. The endurance of lanthanum doped films to high voltage d.c. stressing improves with increasing lanthanum content and a linear extrapolation of log(tbd) with reciprocal electric field indicates a lifetime of ∼10 years. The low-voltage polarizability of fresh sputtered films depends strongly on the polarity; a.c. stressing leads to hysteresis relaxation. The asymmetry in the response to a.c. stressing is possibly due to the structural asymmetry of the device. Neither tbd nor the fatigue-rate seem to depend on the capacitor area for the areas studied.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

1. Parker, L. and Tasch, A. F., IEEE Circuits and Devices Magazine, Jan 1990, pp 1726.Google Scholar
2. Carrano, J. et al. , IEDM Tech. Digest, 1989, pp 255.Google Scholar
3. Sudhama, C. et al. , Mat. Res. Soc. Symp. Proc. Vol. 200, 1990, pp 331.Google Scholar
4. Waser, R. et al. , J. Am. Ceram. Soc., 73 [6] pp 1645–53, 1990.Google Scholar
5. Moazzami, R. et al. , Proc. Int. Rel. Phys. Symp., 1990, pp 231.Google Scholar
6. Payne, D. A., Proc. of the 6th Int. Rel. Phys. Symp., 1968, pp 257.Google Scholar
7. Sze, S.M., Physics of Semiconductor Devices, 2nd Edition (Wiley Eastern Limited), pp403.Google Scholar
8. Sudhama, C. et al. , to be published in Jour. Vac. Sci. and Tech.Google Scholar
9. Moazzami, R. et al. , Proc. of the 1991 Symp. on VLSI Tech.Google Scholar
10. Lambeck, P. V. and Jonker, G. H., J. Phys. Chem. Solids Vol 47, No. 5, pp 453, 1986.Google Scholar
11. Goodenough, J. B., pvt. communication.Google Scholar