Structural and Electronic Properties of GaN/AL Interfaces


The structural and electronic properties of the GaN/Al interface are determined from first principles local density full potential linearized augmented plane wave (FLAPW) calculations. The charge distribution of the gap states as a function of the distance from the interface shows that the gap states induced into the semiconductor by the presence of Al are strongly localized in the junction region. Furthermore, we find that Al does not provide good ohmic contacts on the clean nitrides considered, in contrast with experimental results on chemically treated GaN, but in agreement with recent measurements on the clean surface[1]. We also study some auxiliary systems (all grown on a GaN substrate), i.e. the Al/AlN interface, the GaN/AlN heterojunction and the GaN/Al with an AlN intralayer (GaN-AlN/Al). The transitivity rule for the GaN/Al, AlN/Al and GaN/AlN interfaces is fairly well satisfied and small differences must be ascribed to differences in the interface morphology. Finally, we find that the AIN intralayer does not significantly affect the p-type Schottky barrier height of the GaN/Al interface.

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  1. [1]

    V. M. Bermudez, J. Appl. Phys. 80, 1190 (1996);et al., 79, 110 (1996).

    CAS  Article  Google Scholar 

  2. [2]

    MRS BULLETIN, Vol.22 No.2 (February 1997).

  3. [3]

    J. S. Foresi and T. D. Moustakas, Appl. Phys. Lett. 62, 2859 (1993).

    CAS  Article  Google Scholar 

  4. [4]

    H.J.F. Jansen and A.J. Freeman, Phys. Rev. B 30, 561 (1984).

    CAS  Article  Google Scholar 

  5. [5]

    The SBH changes less than 0.02 eV in going from the 15+7 to the larger 19+9 GaN/Al supercell.

  6. [6]

    P. Hohenberg and W. Kohn, Phys. Rev. 136, B864 (1984); W. Kohn and L. J. Sham, ibid. 145, 561 (1966).

    Article  Google Scholar 

  7. [7]

    H.J. Monkhorst and J.D. Pack, Phys. Rev. B 13, 5188 (1976).

    Article  Google Scholar 

  8. [8]

    Numerical Data and Functional Relationships in Science and Technology, edited by K. H. Hellwege, Landolt-Bornstein Tables, Group III, Vol.17a (springer, New York, 1982).

  9. [9]

    C.G. Van de Walle, Phys. Rev. B 39, 1871 (1988).

    Article  Google Scholar 

  10. [10]

    R. G. Dandrea and C. B. Duke, J. Vac. Sci. Technol. A 11 (4), 848 (1993).

    CAS  Article  Google Scholar 

  11. [11]

    V. Heine, Phys. Rev. 138, A1689 (1965); C. Tejedor, F. Flores and E. Louis, J. Phys. C 10 2163 (1977); J. Tersoff, Phys. Rev. Lett. 52, 465 (1984).

    Article  Google Scholar 

  12. [12]

    A. Baldereschi, S. Baroni and R. Resta, Phys. Rev. Lett. 61, 734 (1988).

    CAS  Article  Google Scholar 

  13. [13]

    C. Berthod, N. Binggeli and A. Baldereschi, J. Vac. Sci. Technol. B 14 (4), 3000 (1996).

    CAS  Article  Google Scholar 

  14. [14]

    S. G. Louie, J. R. Chelikowsky and M. L. Cohen, Phys. Rev. B, 15, 2154 (1977).

    CAS  Article  Google Scholar 

  15. [15]

    S. H. Wei and A. Zunger, Phys. Rev. Lett. 59, 144 (1987); S. Massidda, B. I. Min and A. J. Freeman, Phys. Rev. B 35, 9871 (1987).

    CAS  Article  Google Scholar 

  16. [16]

    L. Hedin, Phys. Rev. 139, A796 (1965).

    Article  Google Scholar 

  17. [17]

    A. Rubio, J. L. Corkill, M. L. Cohen, E. L. Shirley and S. G. Louie, Phys. Rev. B 48, 11810 (1993); M. Palummo et al., Europhys. Lett. 26, 607 (1994).

    CAS  Article  Google Scholar 

  18. [18]

    Wei Su-Huai and Zunger Alex, Appl. Phys. Lett. 69, 2719; E. A. Albanesi, W. R. Lambrecht and B. W. Segall, J. Vac. Sci. Technol. B 12 (4), 2470 (1994).

  19. [19]

    S. Picozzi, A. Continenza and A.J. Freeman, Phys. Rev. B 53, 10852 (1996); N. Tit, M. Peressi and S. Baroni, Phys. Rev. B 48, 17607 (1993).

    CAS  Article  Google Scholar 

  20. [20]

    G. Margaritondo and P. Perfetti in Heterojunction Band Discontinuities, edited by F. Capasso and G. Margaritondo (North-Holland, Amsterdam, 1987), p.59.

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The authors greatfully acknowledge N.Newman, V. Bermudez and N. Binggeli for stimulating discussions. This work was supported by a supercomputing grant at Cineca (Bologna, Italy) through the Istituto Nazionale di Fisica della Materia (INFM), by the MRSEC program of the National Science Foundation (DMR-9632472) at the Materials Research Center of Northwestern University and by a grant of computer time at the NSF-supported Pittsburgh Supercomputing Center.

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Picozzi, S., Continenza, A., Massidda, S. et al. Structural and Electronic Properties of GaN/AL Interfaces. MRS Online Proceedings Library 482, 845–850 (1997).

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