Direct identification of diamond growth precursor using almost pure CH{sub 4} or C{sub 2}H{sub 2} near growth surface
- Department of Chemical Engineering, National Cheng-Kung University Tainan, Taiwan 701, Republic of (China)
Diamond growth was studied by injecting thermally decomposed Cl atoms into CH{sub 4}/H{sub 2} or C{sub 2}H{sub 2}/H{sub 2}. Owing to the extremely short residence time (25 {mu}s) and low gas temperature ({lt}1000{degree}C) in the decomposition system, the gas reaction is insignificant. Therefore, the carbon species near the substrate surface can be nearly identical to the input carbon source. With 0.3{percent} CH{sub 4} being the input carbon source, CH{sub 4} remained the dominant carbon species near the surface (only 2.5{percent} C{sub 2}H{sub 2} was formed), and an almost continuous diamond film was deposited after 2 h growth. Raman spectra confirmed the formation of diamond. With 0.15{percent} C{sub 2}H{sub 2} being the input carbon source, C{sub 2}H{sub 2} remained the dominant carbon species near the surface (10{percent} CH{sub 4} was formed), but only a few very small particles were deposited. Therefore, we conclude that CH{sub 3} radicals seem the only diamond growth precursor under the Cl-rich conditions, whereas C{sub 2}H{sub 2} is not efficient to grow diamond. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 463417
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 70; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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