Roles of Hydrogen Atmospheres in Growth of Ultrananocrystalline Diamond by Pulsed Laser Deposition

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The growth of ultrananocrystalline diamond (UNCD) by pulsed laser deposition necessitates hydrogen atmospheres during the deposition. Optical emission spectroscopy was used to study the roles of the hydrogen atmosphere on the UNCD growth. Time-resolved images of a plume that expanded from a laser-irradiation spot toward a substrate were taken using a high-speed ICCD camera equipped with narrow-bandpass filters. While the plume disappeared at the longest within 1 s in vacuum, the emission from C+ lasted above the substrate surface for approximately 7 microseconds at a hydrogen pressure of 53.3 Pa. Since emission lifetimes of species are approximately 10 nanoseconds, this implies that C+ ions collided actively for such a long time. The hydrogen atmosphere has a role of forming a high number density of C+ ions. In addition, we believe that atomic hydrogen that might be generated by the collisions with carbon species contributes to the UNCD crystallite formation by their terminating the dangling bonds of carbon clusters as theoretically predicted in previous reports.

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Periodical:

Materials Science Forum (Volumes 638-642)

Main Theme:

Edited by:

T. Chandra, N. Wanderka, W. Reimers , M. Ionescu

Pages:

1685-1690

DOI:

10.4028/www.scientific.net/MSF.638-642.1685

Citation:

K. Hanada et al., "Roles of Hydrogen Atmospheres in Growth of Ultrananocrystalline Diamond by Pulsed Laser Deposition", Materials Science Forum, Vols. 638-642, pp. 1685-1690, 2010

Online since:

January 2010

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$35.00

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