Growth mechanism of ZnO low-temperature homoepitaxy

Journal Article · Thu Sep 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3630030· OSTI ID:22038690

Park, S H; Minegishi, T; Lee, H J; Chang, J H; Yao, T ^[1]; Oh, D C ^[2]; Ko, H J ^[3]

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1. Center for Interdisciplinary Research, Tohoku University, Aoba 6-3, Aramaki, Aobak-ku, Sendai 980-8578 (Japan)
2. Center for Optoelectronic Materials and Devices, Department of Defense Science and Technology, Hoseo University, 165 Sechul-ri, Baebang-eup, Asan 336-795 (Korea, Republic of)
3. Photonics Device Team, Korea Photonics Technology Institute, 971-35 Wolchul-dong, Buk-gu, Gwangju, 500-779 (Korea, Republic of)

The authors report on the growth mechanism of ZnO homoepitaxy at the low-temperature range of 500 deg. C, which is unavailable to obtain high-quality ZnO films in heteroepitaxy. One typical set of ZnO films were grown on (0001) ZnO substrates by molecular-beam epitaxy: a standard structure without buffer and two buffered structures with high-temperature (HT) homobuffer and low-temperature (LT) homobuffer. As a result, the LT homobuffered structure had the outstanding material properties: the surface roughness is 0.9 nm, the full width at half maximum of x-ray rocking curve is 13 arcsec, and the emission linewidth of donor-bound excitons is 2.4 meV. In terms of the theoretical interpretation of the experimentally obtained electron mobilities, it was found that the LT homobuffered structure suffers less from the dislocation scattering and the ionized-impurity scattering compared to the HT homobuffered structure. It is proposed that, in the ZnO low-temperature homoepitaxy, the LT homobuffer plays a key role in inducing the complete termination of dislocations in the homointerface and suppressing the outdiffusion of contaminants and point defects on the ZnO surface, which results in the formation of smooth wetting layer on the homointerface.

• OSTI ID: 22038690
• Journal Information: Journal of Applied Physics, Vol. 110, Issue 5; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
DIFFUSION
DISLOCATIONS
ELECTRON MOBILITY
EXCITONS
INTERFACES
LAYERS
MOLECULAR BEAM EPITAXY
POINT DEFECTS
ROUGHNESS
SEMICONDUCTOR MATERIALS
SUBSTRATES
SURFACES
TEMPERATURE DEPENDENCE
X-RAY DIFFRACTION
ZINC OXIDES