Evolution mechanism of nanocrystalline tungsten-carbon and effects on tungsten implanted amorphous hydrogenated carbon

Journal Article · Sat Dec 01 00:00:00 EST 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2821760· OSTI ID:21064469

Ming, Xu; Wei, Zhang; Zhengwei, Wu; Shihao, Pu; Liuhe, Li; Chu, Paul K ^[1]

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1. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

Tungsten doped amorphous carbon films are prepared on silicon (100) by postimplantation of tungsten ions into pure amorphous hydrogenated carbon using the plasma immersion ion implantation technique. The peak concentration of tungsten reaches 27 at. % and W-C nanocrystallites with largest diameters of {approx}5 nm are formed in the near surface region. Both the quantity and size of these nanocrystallites are observed to undergo unique transformation with increasing depths, enabling gradual release of the compressive stress and subsequently leading to better adhesion between the film and substrate. The film structures are evaluated by x-ray photoelectron spectroscopy and glancing angle x-ray diffraction, and high-resolution transmission microscopy is employed to investigate the structural transformation. The mechanical properties of the films including adhesion strength and hardness are determined by nanoindentation and nanoscratch tests. The formation of the nanocrystalline structures can be explained by ion implantation induced damage, chemical effects, and thermodynamics.

• OSTI ID: 21064469
• Journal Information: Journal of Applied Physics, Vol. 102, Issue 11; Other Information: DOI: 10.1063/1.2821760; (c) 2007 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
ADHESION
AMORPHOUS STATE
CARBON
COMPRESSION STRENGTH
CRYSTALS
DOPED MATERIALS
HARDNESS
HYDROGEN
ION IMPLANTATION
NANOSTRUCTURES
PHASE TRANSFORMATIONS
PLASMA
SILICON
THERMODYNAMICS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
TUNGSTEN
TUNGSTEN IONS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY