Abstract
The low pressure metalorganic vapor phase epitaxy growth of wurzite (Al, In, Ga)N heterostructures on sapphire substrates is investigated by quantitative analytical scanning transmission electron microscopy techniques like atomic number (Z-) contrast imaging and convergent beam electron diffraction (CBED). Especially (In, Ga)N quantum wells of different thicknesses as well as superlattices were analyzed with respect to defects, chemical composition variations, interface abruptness and strain (relaxation) effects. The interfaces in In0.12Ga0.88N/GaN quantum wells appear to be asymmetric. Additionally, we found composition variations of ΔxIn≥0.03 within the InGaN quantum wells. The application of electron diffraction techniques (CBED) yields quantitative information on strain and relaxation effects. For the case of 17 nm thick InGaN quantum wells, we observed relaxation effects which are not present in the investigated thin quantum wells of 2 nm thickness. The experimentally obtained diffraction patterns were compared to simulations in order to get values for strain within the quantum wells. Additionally, the influence of dislocations on the digression of superlattices is investigated.
Similar content being viewed by others
References
S. Nakamura, T. Mukai and M. Senoh, J. Appl. Phys. 76, 8189 (1994).
S. Nakamura, M. Senoh, Snagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku and Ysugimoto, Jpn. J. Appl. Phys. 35, L217 (1996).
H. Morkoç, S. Strite, G.B. Gao, M.E. Lin, B. Sverdolv and B. Bruns, J. Appl. Phys. 76 (1994).
F. Scholz,. V. Härle, F. Streuber, A. Sohnmer, H. Bolay, V. Syganow, A. Dörnen, J.S. Im, A. Hangleiter, J.Y. Duboz, P. Galtier, E. Rosencher, O. Ambacher, D. Brunner and H. Lakner, Proc. MRS Fall Meeting 1996 Symp. N (III–V Nitrides) (Pittsburgh, PA: Mater. Res. Soc.).
I-hisu Ho and G.B. Stringfellow, Appl. Phys. Lett. 69, 2701 (1996).
S. Strite and H. Morkoç, J. Vac. Sci. Technol. B 10, 1237 (1992).
H. Lakner, M. Maywald, L.J. Balk and E. Kubalek, Surf. and Int. Anal. 19, 374, (1992).
H. Lakner, B. Bollig, S. Ungerechts and E. Kubalek, J. Appl. Phys. 29, 1767 (1996).
J.C.H. Spence and J.M. Zuo, Electron Microdiffraction, (New York: Plenum Press, 1992).
F. Scholz, V. Härle, F. Streuber, H. Bolay, A. Dörnen, B. Kaufmann, V. Syganow and A. Hangleiter, J. Cryst. Growth 170 (1997).
G. Brockt, C. Mendorf, A. Radefeld, F. Scholz and H. Lakner, to be published in Proc. Xth Conf. on Microscopy of Semiconduncting Materials, (1997).
J.C.H. Spence and J.M. Zuo, Electron Microdiffraction, (New York: Plenum Press, 1992), p. 209.
V.A. Elyukhin and S.A. Nikishin, Semicond. Sci. Technol. 11, 917 (1996).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lakner, H., Brockt, G., Mendorf, C. et al. Characterization of MOVPE-grown (Al, In, Ga) N heterostructures by quantitative analytical electron microscopy. J. Electron. Mater. 26, 1103–1108 (1997). https://doi.org/10.1007/s11664-997-0002-2
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11664-997-0002-2