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Highly resistive sputtered ZnO films implanted with copper

  • M. K. Puchert (a1), A. Hartmann (a1), R. N. Lamb (a1) and J. W. Martin (a2)

Abstract

Polycrystalline (0001)-oriented thin films of ZnO (thickness 120 nm) were deposited by rf magnetron sputtering and post-deposition annealed at 500 °C in oxygen (1 atm). The films were subsequently implanted with copper at doses over the range 1016 to 1017 ions/cm2. X-ray diffraction (XRD) indicates the compressive intrinsic film stress is largely relieved by the preimplantation anneal, and does not change when implanted or when further annealed after implantation, suggesting that the dominant cause of intrinsic stress is the atomic packing density rather than the crystallographic defect density. Resistivity measurements indicate that annealing of pure ZnO films causes the perpendicular resistivity to increase from 1.3 × 105 Ω · cm to 5 × 1010 Ω · cm. Copper implantation results in a lower resistivity of the order of 107 Ω · cm, but subsequent annealing actually increases resistivity beyond that of annealed nonimplanted ZnO to 3 × 1012 Ω · cm. It is proposed that copper increases the resistivity of those annealed films by trapping free electrons with the Cu 3d hole state occurring in CuO (formed predominantly during annealing). In order to check this, the oxidation state of the implanted copper was studied before and after annealing by x-ray photoelectron spectroscopy (XPS) and extended x-ray absorption fine structure (EXAFS). Three oxidation states of copper (Cu0, Cu1+, Cu2+) are detected in the implanted films, and postimplantation annealing results in oxidation of copper to the Cu2+ state, confirming that the presence of CuO in ZnO is associated with increased resistivity.

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1. Blom, F. R., Yntema, D. J., van de Pol, F. C. M., Elwenspoek, M., Fluitman, J. H. J., and Popma, Th. JA., Sensors and Actuators A21A23, 226 (1990).
2. van de Pol, F. C. M., Ceram. Bull. 69, 1959 (1990).
3. Lampe, U. and Muller, J., Sensors and Actuators 18, 269 (1989).
4. Persegol, D., Pic, E., and Plantier, J., J. Appl. Phys. 62, 2563 (1987).
5. Heffner, B. L. and Kino, G. S., Op. Lett. 12, 208 (1987).
6. Godil, A. A., Patterson, D. B., Heffner, B. L., Kino, G. S., and Khuri-Yakob, B. T., Lightwave, J. Technol. 6, 1586 (1988).
7. Koch, M., Timbrell, P. Y., and Lamb, R. N., Semiconductor Sci. Technol. 10, 1523 (1995).
8. Shiosaki, T. and Kawabata, A., Appl. Phys. Lett. 25, 10 (1974).
9. Srivastava, J. K., Agarwal, Lily, and Bhattacharyya, A. B., J. Elec-trochem. Soc. 136, 3414 (1989).
10. Labeau, M., Rey, P., Deschanvres, J.L., Joubert, J.C., and Delabouglise, G., Thin Solid Films 213, 94 (1992).
11. Chernets, A. N., Thin Solid Films 18, 247 (1973).
12. Puchert, M. K., Timbrell, P. Y., and Lamb, R. N., J. Vac. Sci. Technol. A, in press (1996).
13. Brown, I. G., Galvin, J.E., Gavin, B. F., and MacGill, R. A., Rev. Sci. Instr. 57, 1069 (1986).
14. Azaroff, Leonid V., Elements of X-ray Crystallography (McGraw-Hill, New York, 1968), pp. 551552.
15. Nelson, J. B. and Riley, D. P., Phys. Soc. 57, 160 (1944).
16. Sathe, A. D. and Kim, E. S., The 7th International Conference on Solid-State Sensors and Actuators (1993).
17. Numerical Data and Functional Relationships in Science and Technology, edited by Hellwege, K. H. and Hellwege, A. M. (Springer, Berlin, 1964), group III, Vol. 2, p. 58.
18. Foran, G. J., Cookson, D. J., and Garrett, R. F., in Synchrotron Radiation Facilities in Asia, edited by Ohta, T., Suga, S., and Kikuta, S. (Ionics Publishing, Tokyo, 1994), pp. 119124.
19. Kaltofen, R. and Weise, G., J. Nucl. Mater. 200, 375 (1993).
20. Ghijsen, J., Tjeng, L. H., van Elp, J., Eskes, H., Westerink, J., and Sawatzky, G. A., Phys. Rev. B 38, 11322 (1988).
21. van der Laan, G., Westra, C., Haas, C., and Sawatzky, G. A., Phys. Rev. B 23, 4369 (1981).
22. Stern, E. A., Sayers, D. E., and Lytle, F.W., Phys. Rev. B 11, 4836 (1975).
23. Teo, B. K., in EXAFS Spectroscopy, edited by Teo, B. K. and Joy, D. C. (Plenum Press, New York, London, 1981).

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Highly resistive sputtered ZnO films implanted with copper

  • M. K. Puchert (a1), A. Hartmann (a1), R. N. Lamb (a1) and J. W. Martin (a2)

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