Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-06-27T08:45:13.128Z Has data issue: false hasContentIssue false
  • English
  • Français

Electrical, Optical, Structural, and Analytical Properties of Very Pure GaN

Published online by Cambridge University Press:  11 February 2011

D. C. Look ,
J. R. Sizelove ,
J. Jasinski ,
Z. Liliental-Weber ,
K. Saarinen ,
S. S. Park  and
J. H. Han
D. C. Look
Affiliation:
Semiconductor Research Center, Wright State University, Dayton, OH 45435
J. R. Sizelove
Affiliation:
Air Force Research Laboratory, AFRL/MLPS, Wright-Patterson AFB, OH 45433
J. Jasinski
Affiliation:
Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720
Z. Liliental-Weber
Affiliation:
Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720
K. Saarinen
Affiliation:
Helsinki University of Technology, P.O. Box 1100, FIN-02015, Espoo, Finland
S. S. Park
Affiliation:
Samsung Advanced Institute of Technology, P.O. Box 111, Suwon, Korea, 440–600
J. H. Han
Affiliation:
Samsung Advanced Institute of Technology, P.O. Box 111, Suwon, Korea, 440–600
Get access

Abstract

Present hydride vapor phase epitaxial growth of GaN on Al2O3 can produce material of very high quality, especially in regions of the crystal far from the substrate/epilayer interface. In the present study, we characterize a 248-μm-thick epilayer, which had been separated from its Al2O3 substrate and etched on top and bottom to produce flat surfaces. Temperature-dependent Hall-effect data have been fitted to give the following parameters: mobility μ(300) = 1320 cm2/V-s; μ(peak) = 12,000 cm2/V-s; carrier concentration n(300) = 6.27 × 1015 cm−3; donor concentration ND = 7.8 × 1015 cm−3; acceptor concentration NA = 1.3 × 1015 cm−3; and effective donor activation energy ED = 28.1 meV. These mobilities are the highest ever reported in GaN, and the acceptor concentration, the lowest. Positron annihilation measurements give a Ga vacancy concentration very close to NA, showing that the dominant acceptors are likely native defects. Secondary ion mass spectroscopic measurements show that ND is probably composed of the common donors O and Si, with [O] > [S1]. Transmission electron microscopy measurements yield threading dislocation densities of about 1 × 107 cm−2 on the bottom (N) face, and < 5 × 105 cm−2 on the top (Ga) face. Photoluminescence (PL) spectra show a strong donor-bound exciton (D°X) line at 3.47225 eV, and a weaker one at 3.47305 eV; each has a linewidth of about 0.4 meV. In the two-electron satellite region, a strong line appears at 3.44686 eV, and a weaker one at 3.44792 eV. If the two strong lines represent the same donor, then ED,n=1 – ED,n=2 = 25.4 meV for that donor, and the ground-state activation energy (EC – ED,n=1) is (4/3)25.4 = 33.9 meV in a hydrogenic model, and 32.7 meV in a somewhat modified model. The measured Hall-effect donor energy, 28.1 meV, is smaller than the PL donor energy, as is nearly always found in semiconductors. We show that the difference in the Hall and PL donor energies can be explained by donor-band conduction via overlapping donor excited states, and the effects of non-overlapping excited states which should be included in the n vs. T data analysis (charge balance equation).

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 743: Symposium L – GaN and Related Alloys , 2002 , L10.1
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Maruska, H.P. and Tietjen, J.J., Appl. Phys. Lett. 15, 327 (1969).Google Scholar
2. Look, D.C., Stutz, C.E., Molnar, R.J., Saarinen, K., and Liliental-Weber, Z., Solid State Commun. 117, 571 (2001).Google Scholar
3. Jasinski, J. and Liliental-Weber, Z., J. Electron. Mater. 31, 429 (2002).Google Scholar
4. Molnar, R.J., Nichols, K.B., Makai, P., Brown, E.R., and Melngailis, I., Mater. Res. Soc. Symp. Proc. 378, 479 (1995).Google Scholar
5. Park, S.S., Park, I-W., and Choh, S.H., Jpn. J. Appl. Phys., Part 2 39, L1141 (2000).Google Scholar
6. Oh, E., Lee, S.K., Park, S.S., Lee, K.Y., Song, I.J., and Han, J.Y., Appl. Phys. Lett. 78, 273 (2001).Google Scholar
7. Look, D.C. and Molnar, R.J.. Appl. Phys. Lett. 70, 3377 (1997).Google Scholar
8. East, Evans, 104 Windsor Center, East Windsor, NJ, 08520Google Scholar
9. Moore, W.J., Freitas, J.A. Jr, Lee, S.K., Park, S.S., and Han, J.Y., Phys. Rev. B 65, 081201 (2002).Google Scholar
10. Saarinen, K., Nissilä, J., Hautojärvi, P., Likonen, J., Suski, T., Grzegory, I., Lucznik, B., and Porowski, S., Appl. Phys. Lett. 75, 2441 (1999).Google Scholar
11. Oila, J., Kivioja, J., Ranki, V., Saarinen, K., Look, D.C., Molnar, R.J., and Park, S.S. (to be published).Google Scholar
12. Neugebauer, J. and Van de Walle, C.G., Phys. Rev. B 50, 8067 (1994).Google Scholar
13. Kornitzer, K., Ebner, T., Thonke, K., Sauer, R., Kirchner, C., Schwegler, V., Kamp, M., Leszczynski, M., Grzegory, I., and Porowski, S., Phys. Rev. B 60, 1471 (1999).Google Scholar
14. Look, D.C., Electrical Characterization of GaAs Materials and Devices (Wiley, New York, 1989), Ch.1.Google Scholar
15. Rode, D.L., Semicond. Semimetals 10, 1 (1975).Google Scholar
16. Nag, B.R., Electron Transport in Compound Semiconductors (Springer, Berlin, 1980).Google Scholar
17. Eddolls, D.V., Knight, J.R., and Wilson, B.L.H., in Proc. Int. Symp. on GaAs, ed. by Franks, J. and Moore, W.G. (Inst. Phys., London, 1967) pp. 3–9.Google Scholar
18. Stillman, G.E. and Wolfe, C.M., Thin Solid Films 31, 69 (1976).Google Scholar
19. Look, D.C. and Sizelove, J.R., Appl. Phys. Lett. 79, 1133 (2001).Google Scholar