ADF-STEM Imaging of Strained GaN0.045As0.955 Epitaxial Layers on (100) GaAs Substrates

Abstract

The annular dark field (ADF) image contrast of a 0.92% tensile strained GaN0.045As0.955 layer on GaAs substrate was studied with a scanning transmission electron microscope (STEM) as a function of ADF detector inner semi-angles ranging from 28 mrad to 90 mrad. The GaN0.045As0.955 layers were brighter than the surrounding GaAs for the ADF detector semi-angle up to 65 mrad, and the measured contrast decreased with increasing ADF detector inner semi-angle. For a 37 nm thick specimen, the GaN0.045As0.955 intensity is about 13% higher than that of GaAs for the 28 mrad ADF detector inner semi-angle. Multislice simulations show that the displacement around substitutional N atoms plays an important role in the observed ADF-STEM contrast, while the contribution to the contrast due to misfit strain between GaN0.045As0.955 and GaAs is small.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    A.J. McGibbon, S.J. Pennycook and J.E. Angelo, Science, 269 (1995) 519.

    CAS  Article  Google Scholar 

  2. 2.

    P.M. Voyles, D.A. Muller, J.L. Grazul, P.H. Citrin and H.-J. Gossmann, Nature, 416 (2002) 826.

    CAS  Article  Google Scholar 

  3. 3.

    P.D. Nellist and S.J. Pennycook, Science, 274 (1996) 413.

    CAS  Article  Google Scholar 

  4. 4.

    D.D. Perovic, C.J. Rossouw and A. Howie, Ultramicroscopy, 52 (1993) 353.

    CAS  Article  Google Scholar 

  5. 5.

    G. Duscher, S.J. Pennycook, N.D. Browning, R. Rupangudi, C. Takoudis, H.J. Gao and R. Singh, Characterization and Metrology for ULSI Technology (American Institute of Physics, New Yotk, 1998) p. 191.

  6. 6.

    Z. Yu, D.A. Muller and J. Silcox, J. Appl. Phys., 95 (2004) 3362.

    CAS  Article  Google Scholar 

  7. 7.

    M. Fischer, M. Reinhardt, A. Forchel, Electron. Lett. 36 (2000) 1208.

    CAS  Article  Google Scholar 

  8. 8.

    J.A. Gupta, P.J. Barrios, G. Pakulski, X. Zhang and X. Wu, Electron. Lett. 41 (2005) 1061.

    Google Scholar 

  9. 9.

    J.A. Gupta, P.J. Barrios, J.A. Caballero, D. Poitras, G.C. Aers, G. Pakulski and X. Wu, Appl. Phys. Lett. 89 (2006) 151119.

    Article  Google Scholar 

  10. 10.

    J.A. Gupta, I.S. Sproule, X. Wu and Z.R. Wasilewski, J. Crystal Growth, 291, (2006) 86.

  11. 11.

    X. Wu, J.-M. Baribeau, J.A. Gupta and M. Beaulieu, J. Crystal Growth, 282 (2005) 18.

    CAS  Article  Google Scholar 

  12. 12.

    J.A. Gupta, et al. J. Crystal Growth, 242 (2002) 141.

    CAS  Article  Google Scholar 

  13. 13.

    E.J. Kirkland, Advanced Computing in Electron Microscopy (Plenum Press, New York, 1998).

  14. 14.

    C.R. Hall, P.B. Hirsch and G.R. Booker, Phil. Mag. 14 (1966) 979.

    CAS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to X. Wu.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wu, X., Robertson, M.D., Gupta, J.A. et al. ADF-STEM Imaging of Strained GaN0.045As0.955 Epitaxial Layers on (100) GaAs Substrates. MRS Online Proceedings Library 982, 103 (2006). https://doi.org/10.1557/PROC-0982-KK01-03

Download citation