Effect of chlorine addition on diamond growth using methane/hydrogen reactants
- Department of Chemical Engineering, National Cheng-Kung University Tainan, Taiwan 701, Republic of (China)
The effect of Cl{sub 2} addition on diamond growth using CH{sub 4}/H{sub 2} was studied in a hot-filament chemical vapor deposition reactor. Cl{sub 2} was mostly converted into HCl before arriving at the hot filament. Cl{sub 2} addition enhanced the diamond growth rate. The growth rate enhancement was more pronounced at a lower growth temperature and lower reactor pressure, implying that the CH{sub 3} and CH{sub 4} interconversion reactions were not in partial equilibrium below 5 Torr. Cl{sub 2} addition also reduced the activation energy by the same value for both pressures at 1 and 5 Torr, suggesting that the H and Cl exchange reaction was in partial equilibrium. However, Cl{sub 2} addition degraded the film quality, and the deterioration became more pronounced at a higher Cl{sub 2} concentration or lower substrate temperature. The effects of chlorine are suggested to include: (i) the fast reaction of Cl with surface bonded C{endash}H; (ii) the fast reaction of Cl with CH{sub 4}; (iii) the weak ability of Cl to adsorb on C{double_bond}C; and (iv) the weak ability of Cl to break C{endash}C to remove the improperly adsorbed CH{sub 3}. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 496403
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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