Skip to main content Accessibility help

Disordering and Characterization Studies of 69GaAs/71GaAs Isotope Superlattice Structures: The Effect of Outdiffusion of the Substrate Dopant Si

  • T. Y. Tan (a1), H. M. You (a1), S. Yu (a1), U. M. Gitesele (a1), W. Jäger (a2), F. Zypman (a3), R. Tsu (a3) and S. -T. Lee (a4)...


Undoped 69GaAs/71GaAs isotope superlattice structures grown by MBE on n-type GaAs substrates, doped by Si to ∼3×1018 cm−3, have been used to study Ga self-diffusion in GaAs by disordering reactions. In the temperature range of 850–960°C, the SIMS measured Ga self-diffusivity values showed an activation enthalpy of 4 eV, and are larger than previously compiled Ga self-diffusivity and Al-Ga interdiffusivity values obtained under thermal equilibrium and intrinsic conditions, which are characterized by a 6 eV activation enthalpy. SIMS, CV, and TEM characterizations showed that the as-grown superlattice layers were intrinsic which became p-type with hole concentrations up to ∼2×1017 cm−3 after annealing, because the layers contain carbon. Dislocations of a density of ∼106-107 cm−2 were also present. However, the factor responsible for the presently observed larger Ga self-diffusivity values appears to be Si outdiffusion from the substrate, which was determined using CV measurements. Outdiffusion of Si decreases the n value in the substrate which causes the release of excess Ga vacancies into the superlattice layers where the supersaturated Ga vacancies enhance Ga self-diffusion.



Hide All
1. Tan, T. Y. and Gösele, U., Appl. Phys. Lett. 52, 1240 (1988).
2. Deppe, D. G. and Holonyak, N. Jr, J. Appl. Phys. 66, R93 (1988).
3. Palfrey, H. D., Brown, M. and Willoughby, A. F. W., J. Electrochem. Soc. 128, 2224 (1981).
4. Chang, L. L. and Koma, A., Appl. Phys. Lett. 29, 138 (1976).
5. Lee, J. -C., Schlesinger, T. E. and Kuech, T. F., J. Vac. Sci. Technol. B5, 1187 (1987).
6. Goldstein, B., Phys. Rev. 121, 1305 (1961).
7. Petroff, P. M., J. Vac. Sci. Technol. 14, 973 (1977).
8. Fleming, R. M., McWhan, D. B., Gossard, A. C., Wiegmann, W. and Logan, R. A., J. Appl. Phys. 51, 357 (1980).
9. Camras, M. D., Holonyak, N. Jr, Burnham, R. D., Streifer, W., Scifres, D. R., Paoli, T. L., and Lindström, C., J. Appl. Phys. 54, 5637 (1983).
10. Schlesinger, T. E. and Kuech, T. F., Appl. Phys. Lett. 49, 518 (1986).
11. Cibert, J., Petroff, P. M., Dolan, G. J., Pearton, S. J., Gossard, A. C. and English, J. H., Appl. Phys. Lett, 49, 1275 (1986).
12. Hsieh, K. Y., Lo, Y. C., Lee, J. H., and Kolbas, R. M., in Inst. Conf. Ser. No. 96, (1988) p. 393.
13. Mei, P., Yoon, H. W., Venkatesan, T., Schwarz, S. A. and Harbison, J. B., Appl. Phys. Lett. 50, 1823 (1987).


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