| Autor: |
Butcher, K. S. A., Timmers, H., Afifuddin, Chen, Patrick P.-T., Weijers, T. D. M., Goldys, E. M., Tansley, T. L., Elliman, R. G., Freitas, J. A. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 9/15/2002, Vol. 92 Issue 6, p3397, 7p, 5 Black and White Photographs, 1 Chart, 4 Graphs |
| Abstrakt: |
The grain size for polycrystalline GaN, grown in low-temperature gallium-rich conditions, is shown to be correlated to the oxygen content of the films. Films with lower oxygen content were observed to have larger crystals with an increased tendency to a single-preferred crystal orientation. Elastic recoil detection analysis with heavy ions (i.e., 200 MeV [sup 197] Au ions) was used to determine the composition of the GaN films grown for the study, including the hydrogen, carbon, gallium, nitrogen, and oxygen content. Atomic force microscopy and x-ray diffraction were used to study the sample morphology. From these measurements, the available surface area of the films was found to be sufficient for a significant proportion of the oxygen present in the films to segregate at the grain boundaries. This interpretation is consistent with earlier theoretical studies of the formation and segregation of the V[sub Ga]-(O[sub N])[sub 3] defect complex at dislocation sites in gallium-rich GaN. For this work, however, the defect complex is believed to segregate at the grain boundary of the polycrystalline GaN. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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