Plasma-chemical processes in microwave plasma-enhanced chemical vapor deposition reactors operating with C/H/Ar gas mixtures
- Skobel'tsyn Institute of Nuclear Physics, Moscow State University, Vorob'evy gory, Moscow 119991 (Russian Federation)
- School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom)
Microwave (MW) plasma-enhanced chemical vapor deposition (PECVD) reactors are widely used for growing diamond films with grain sizes spanning the range from nanometers through microns to millimeters. This paper presents a detailed description of a two-dimensional model of the plasma-chemical activation, transport, and deposition processes occurring in MW activated H/C/Ar mixtures, focusing particularly on the following base conditions: 4.4%CH{sub 4}/7%Ar/balance H{sub 2}, pressure p=150 Torr, and input power P=1.5 kW. The model results are verified and compared with a range of complementary experimental data in the companion papers. These comparators include measured (by cavity ring down spectroscopy) C{sub 2}(a), CH(X), and H(n=2) column densities and C{sub 2}(a) rotational temperatures, and infrared (quantum cascade laser) measurements of C{sub 2}H{sub 2} and CH{sub 4} column densities under a wide range of process conditions. The model allows identification of spatially distinct regions within the reactor that support net CH{sub 4}{yields}C{sub 2}H{sub 2} and C{sub 2}H{sub 2}{yields}CH{sub 4} conversions, and provide a detailed mechanistic picture of the plasma-chemical transformations occurring both in the hot plasma and in the outer regions. Semianalytical expressions for estimating relative concentrations of the various C{sub 1}H{sub x} species under typical MW PECVD conditions are presented, which support the consensus view regarding the dominant role of CH{sub 3} radicals in diamond growth under such conditions.
- OSTI ID:
- 21179991
- Journal Information:
- Journal of Applied Physics, Vol. 104, Issue 11; Other Information: DOI: 10.1063/1.3035850; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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