Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-19T02:13:14.162Z Has data issue: false hasContentIssue false

Deep States in GaN Studied by Thermally Stimulated Current Spectroscopy

Published online by Cambridge University Press:  21 February 2011

Z.C. Huang
Affiliation:
Hughes STX Corporation, 7701 Greenbelt Road, Suite 400, Greenbelt, MD 20770
J.C. Chen
Affiliation:
Department of Computer Science and Electrical Engineering, University of Maryland Baltimore County, Baltimore, MD 21228
D.B. Mott
Affiliation:
Goddard Space Flight Center, Code 718.1, NASA, Greenbelt, MD 20771
Get access

Abstract

Deep levels in insulating GaN grown by metalorganic chemical vapor deposition have been studied using thermally stimulated current (TSC) and photocurrent (PC) spectroscopies. Five main traps were observed by TSC measurement in the as-grown undoped GaN in the range of 0-0.75 eV below the conduction band edge or above the valence band edge. Their activation energies were 0.11, 0.24, 0.36, 0.53 and 0.62 eV, respectively. PC measurements showed three deep levels located within the bandgap at 1.32, 1.70 and 2.36 eV, respectively. Furnace annealing was carried out on GaN for identifying all the observed deep levels. We have found that the 0.24, 0.36 and 0.53 eV traps were eliminated by annealing at 1000°C under N2for six hours, whereas the 0.62 eV trap density increased after annealing. The three deep levels detected by the PC measurement were not affected by annealing. The 1.70 eV trap, which is located at the midgap, does not seem to compensate with narrow donors. We attribute the 0.11 eV trap to surface states, and the 0.62 eV trap to nitrogen vacancies.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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 Khan, M.A., Kuznia, J.N., Olson, D.T., Van Hove, J.M., Blasingame, M. and Reitz, L.F.. Appl. Phys. Lett., 60, 2917 (1992)Google Scholar
2 Lester, S.D., Ponce, F.A., Craford, M.G. and Steigerwald, D.A., Appl. Phys. Lett., 66, 1249 (1995)Google Scholar
3 Qian, W., Skowronski, M., De Graef, M., Doverspike, K., Rowland, L.B. and Gaskill, D. K., Appl. Phys. Lett., 66, 1252 (1995)Google Scholar
4 Kurtin, S., McGill, T.C., and Mead, C.A., Phys. Rev. Lett., 22, 1433 (1969)Google Scholar
5 Xie, K., Huang, Z.C., Wie, C.R., J. Electron. Mater., 20, 553 (1991)Google Scholar
6 Huang, Z.C., Xie, K. and Wie, C.R., Rev. Sci. Instrum., 62, 1951 (1991)Google Scholar
7 Gotz, W., Johnson, N.M., Amano, H. and Akasaki, I., Appl. Phys. Lett., 65, 463 (1994)Google Scholar
8 Lee, W.I., Huang, T.C., Guo, J.D. and Feng, W.S., Appl. Phys. Lett., 67, 1721 (1995)Google Scholar
9 Huang, Z.C., Chen, J.C. and Brent, D., Mott to be submitted.Google Scholar
10 Martin, G.M., Farges, J.P., Jacob, G., and Hallais, J. P., J. Appl. Phys., 51, 2840 (1980)Google Scholar
11 Ta, L.B., Hobgood, H.M., Rohatgi, A., and Thomas, R.N., J. Appl. Phys., 53, 5771 (1982)Google Scholar
12 Strite, S. and Morkoc, H., J. Voc. Sci. Technol. B10, 1237 (1992)Google Scholar
13 Morkoc, H., Strite, S., Gao, G.B., Lin, M.E., Sverdla, B. and Burns, M., J. Appl. Phys., 76, 1363 (1994)Google Scholar