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Author Jiao, S. ♦ Sumant, A. ♦ Kirk, M. A. ♦ Gruen, D. M. ♦ Krauss, A. R. ♦ Auciello, O.
Sponsorship (US)
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Publisher The American Physical Society
Language English
Subject Keyword MATERIALS SCIENCE ♦ CHEMICAL VAPOR DEPOSITION ♦ DIAMONDS ♦ ELECTRON MICROSCOPY ♦ GRAIN BOUNDARIES ♦ MICROSTRUCTURE ♦ PLASMA ♦ TRANSMISSION ELECTRON MICROSCOPY
Abstract Ultrananocrystalline diamond (UNCD) films, grown using microwave plasma-enhanced chemical vapor deposition with gas mixtures of Ar{endash}1%CH{sub 4} or Ar{endash}1%CH{sub 4}{endash}5%H{sub 2}, have been examined with transmission electron microscopy (TEM). The films consist of equiaxed nanograins (2{endash}10 nm in diameter) and elongated twinned dendritic grains. The area occupied by dendritic grains increases with the addition of H{sub 2}. High resolution electron microscopy shows no evidence of an amorphous phase at grain boundaries, which are typically one or two atomic layer thick (0.2{endash}0.4 nm). Cross-section TEM reveals a noncolumnar structure of the films. The initial nucleation of diamond occurs directly on the Si substrate when H{sub 2} is present in the plasma. For the case of UNCD growth from a plasma without addition of H{sub 2}, the initial nucleation occurs on an amorphous carbon layer about 10{endash}15 nm thick directly grown on the Si substrate. This result indicates that hydrogen plays a critical role in determining the nucleation interface between the UNCD films and the Si substrate. The relation between diamond nuclei and Si is primarily random and occasionally epitaxial. {copyright} 2001 American Institute of Physics.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2001-07-01
Publisher Department Argonne National Laboratory (ANL), Argonne, IL
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 90
Issue Number 1
Organization Argonne National Laboratory (ANL), Argonne, IL


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