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Accession Number:
ADA247944
Title:
Hydrogen Assisted Heat Transfer during Diamond Growth Using Carbon and Tantalum Filaments
Descriptive Note:
Technical rept.
Corporate Author:
PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB
Report Date:
1992-03-11
Pagination or Media Count:
14.0
Abstract:
Much of the previous work on the role of atomic hydrogen in diamond has been focussed on its formation on various refractory metal filaments. Its reaction in the gas phase and its role in the growth mechanism. In contrast. the effect of atomic hydrogen recombination on substrate heating is addressed in this paper. Experiments were conducted in vacuum. helium and hydrogen environments. Tantalum and carbon filaments were used to vary atomic hydrogen generation rates. Furthermore methane was added in some experiments to determine its effect on hydrogen assisted chemical of the substrate. The results indicate that when substantial amounts of atomic hydrogen are generated at the filament. reactions of atomic hydrogen at the diamond growth surface have a pronounced effect on the substrate temperature. Use of carbon Maments lead to significantly diminished atomic hydrogen generation rates and much lower substrate temperatures. Additions of small amounts of methane to hydrogen also resulted in reduced atomic hydrogen generation rates and consequently, lower substrat temperatures. This document has been approved for public release and sale its distribution is unlimited.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
