Reconstructions of GaN(0001) and (0001) surfaces: Ga-rich metallic structures

Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures

Volumn 16, Issue 4, 1998, Pages 2242-2249

  Smith, A R ^a   Feenstra, R M ^a   Greve, D W ^b   Shin, M S ^b   Skowronski, M ^b   Neugebauer, J ^c   Northrup, J E ^d  

^a CARNEGIE MELLON UNIVERSITY   (United States)

^b CARNEGIE MELLON UNIVERSITY   (United States)

^c FRITZ HABER INSTITUT DER MAX PLANCK GESELLSCHAFT   (Germany)

^d PALO ALTO RESEARCH CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 11644265156     PISSN: 10711023     EISSN: None     Source Type: Journal    
DOI: 10.1116/1.590156     Document Type: Article

References (26)

1. J. E. Northrup and J. Neugebauer, Phys. Rev. B 53, 10477 (1996).
2. J. E. Northrup, R. Di Felice, and J. Neugebauer, Phys. Rev. B 55, 13 878 (1997).
3. J. Neugebauer, T. Zywietz, M. Scheffler, J. E. Northrup, and C. G. Van de Walle (unpublished).
4. J. Fritsch, O. F. Sankey, K. E. Schmidt, and J. B. Page (unpublished).
5. M. Wassermeier, A. Yamada, H. Yang, O. Brandt, J. Behrend, and K. H. Ploog, Surf. Sci. 385, 178 (1997).
6. A. R. Smith, R. M. Feenstra, D. W. Greve, J. Neugebauer, and J. E. Northrup, Phys. Rev. Lett. 79, 3934 (1997).
7. A. R. Smith, R. M. Feenstra, D. W. Greve, J. Neugebauer, and J. Northrup, Appl. Phys. A (to be published).
8. A. R. Smith, V. Ramachandran, R. M. Feenstra, D. W. Greve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. E. Northrup, J. Vac Sci. Technol. A (to be published).
9. A. R. Smith, R. M. Feenstra, D. W. Greve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. E. Northrup, Appl. Phys. Lett. (submitted).
10. P. Hacke, G. Feuillet, H. Okumura, and S. Yoshida, Appl. Phys. Lett. 69, 2507 (1996).
11. Z. Yu, S. L. Buczkowski, N. C. Giles, T. H. Myers, and M. R. Richards-Babb, Appl. Phys. Lett. 69, 2731 (1996).
12. L. T. Romano and T. H. Myers, Appl. Phys. Lett. 71, 3486 (1997).
13. E. J. Tarsa, B. Heying, X. H. Wu, P. Fini, S. P. DenBaars, and J. S. Speck, J. Appl. Phys. 82, 5472 (1997).
14. L. J. Whitman, P. M. Thibado, S. C. Erwin, B. R. Bennett, and B. V. Shanabrook, Phys. Rev. Lett. 79, 693 (1997).
15. W. Harrison, J. Vac. Sci. Technol. 16, 1492 (1979); M. D. Pashley, Phys. Rev. B 40, 10 481 (1989); J. E. Northrup and S. Froyen, ibid. 50, 2015 (1994).
16. W. Harrison, J. Vac. Sci. Technol. 16, 1492 (1979); M. D. Pashley, Phys. Rev. B 40, 10 481 (1989); J. E. Northrup and S. Froyen, ibid. 50, 2015 (1994).
17. W. Harrison, J. Vac. Sci. Technol. 16, 1492 (1979); M. D. Pashley, Phys. Rev. B 40, 10 481 (1989); J. E. Northrup and S. Froyen, ibid. 50, 2015 (1994).
18. A. R. Sandy, S. G. J. Mochrie, D. M. Zehner, G. Grübel, K. G. Huang, and D. Gibbs, Phys. Rev. Lett. 68, 2192 (1992).
19. D. L. Abernathy, D. Gibbs, G. Grübel, K. G. Huang, S. G. J. Mochrie, A. R. Sandy, and D. M. Zehner, Surf. Sci. 283, 260 (1993).
20. U. Harten, A. M. Lahee, J. P. Toennies, and Ch. Wöll, Phys. Rev. Lett. 54, 2619 (1985).
21. A. R. Smith, R. M. Feenstra, D. W. Greve, M.-S. Shin, M. Skowronski, J. Neugebauer, and J. E. Northrup (unpublished).
22. Proper treatment of STM tips in order to achieve reproducible spectroscopic features has been discussed in detail elsewhere; see, for example, R. M. Feenstra, Phys. Rev. B 50, 4561 (1994).
23. R. M. Feenstra, J. A. Stroscio, and A. P. Fein, Surf. Sci. 181, 295 (1987).
24. The lateral calibration of the STM depends on the length of the probe tip, due to the bending motion of the tube scanner.
25. L. E. Davis, N. C. MacDonald, P. W. Palmberg, G. E. Riach, and R. E. Weber, Handbook of Auger Electron Spectroscopy, 2nd ed. (Physical Electronics Division, Eden Prairie, MN, 1978), p. 13.
26. We note that the Ga/N Auger ratio depends on the details of the given reconstruction. For example, the adatoms making up the GaN(0001)3 × 3 reconstruction are known from theoretical calculation to be at a height of only 0.9 Å above the first Ga adlayer. If this value is used in the Auger model calculation, the computed Ga/N ratio for the 3 × 3 is 0.70. Using a height of 2.1 Å above the first Ga adlayer yields a Ga/N ratio of 0.74. But of course the higher order reconstructions, such as 6 × 6 and c(6 × 12), may contain adatoms at heights greater than 0.9 Å above the first Ga adlayer but somewhat less that 2.1 Å. In fact, the calculated Ga/N ratios using both 0.9 and 2.1 Å adatom heights above the first Ga adlayer bracket the experimentally measured values shown in Fig. 6(a).