Mechanism for persistent hexagonal island formation in AlN buffer layer during growth on Si (111) by plasma-assisted molecular beam epitaxy
- Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan (China) and Frontier Material and Micro/Nano Science and Technology Center, National Cheng Kung University, Tainan, 70101 Taiwan (China)
The characteristics of structure and morphology of AlN grown by a growth interruption method on Si (111) with plasma-assisted molecular beam epitaxy are investigated. It is found that the growth interruption method would improve the surface flatness of the AlN layer without the formation of Al droplets. However, AlN hexagonal islands were present and persistent throughout the entire growth owing to effective strain relaxation and Eherlich-Schowebel barrier effect of preexistent surface islands grown on higher terraces of the Si substrate. The density of threading dislocations underneath the hexagonal islands is much less than elsewhere in the film, which is presumably due to dislocation annihilation during the island growth process.
- OSTI ID:
- 20971934
- Journal Information:
- Applied Physics Letters, Vol. 90, Issue 21; Other Information: DOI: 10.1063/1.2741054; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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