S.A. Goodman, F.D. Auret
University of Pretoria
F.K. Koschnick, J-M. Spaeth
Universitat GH Paderborn
B. Beaumont, P. Gibart
CRHEA-CNRS
This article was presented as part of Symposium G, "Gallium Nitride and Related Alloys" at the 1998 Fall Meeting of the Materials Research Society held in Boston, Massachusetts, November 30-December 4.
We report on the electrical properties of defects as determined by deep level transient spectroscopy (DLTS) introduced in epitaxially grown n-GaN by 2.0 MeV protons and 5.4 MeV He-ions. After He-ion bombardment three electron traps ER3 (Ec - 0.196 eV), ER4 (Ec - 0.78 eV), and ER5 (Ec - 0.95 eV) were introduced uniformly in the region profiled by DLTS with introduction rates of 3270 ± 200, 1510 ± 300, and 3030 ± 500 cm-1 respectively. Capture cross section measurements revealed that the electron capture kinetics of ER5 is similar to that of a line defect. A defect with similar electronic properties as ER3 is observed after 2.0 MeV proton irradiation. The emission rate of ER3 depends on the electric field strength in the space-charge region. This emission rate is modelled according to the Poole-Frenkel distortion of a square well with a radius of 20 ± 2 Å or alternatively, a Gaussian well with a characteristic width of 6.0 ± 1 Å. Hence, we conclude that ER1 is a point defect which appears to have an acceptor like character. Two additional electron traps, ER1 (Ec - 0.13 eV) and ER2 (Ec - 0.16eV) with introduction rates of 30 ± 10 and 600 ± 100 cm-1 not thusfar observed after electron or He-ion bombardment were observed after proton irradiation.
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 4S1, G6.12 (1999).
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