Advanced laser diagnostics for diamond deposition research
- Stanford Univ., CA (United States)
Chemical Vapor Deposition (CVD) using thermal plasmas is attractive for diamond synthesis applications due to the inherently high reactant densities and throughput, but the associated high gas-phase collision rates in the boundary layer above the substrate produce steep thermal and species gradients which can drive the complex plasma chemistry away from optimal conditions. To understand and control these environments, accurate measurements of temperature and species concentrations within the reacting boundary layer are needed. This is challenging in atmospheric pressure reactors due to the highly luminous environment, steep thermal and species gradients, and small spatial scales. The applicability of degenerate four-wave mixing (DFWM) as a spectroscopic probe of atmospheric pressure reacting plasmas has been investigated. This powerful, nonlinear technique has been applied to the measurement of temperature and radical species concentrations in the boundary layer of a diamond growth substrate immersed in a flowing atmospheric pressure plasma. In-situ measurements of CH and C{sub 2} radicals have been performed to determine spatially resolved profiles of vibrational temperature, rotational temperature, and species concentration. Results of these measurements are compared with the predictions of a detailed numerical simulation.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- OSTI ID:
- 175501
- Report Number(s):
- CONF-9505200-; ON: DE96000983; TRN: 96:003535
- Resource Relation:
- Conference: 13. symposium on energy engineering sciences, Argonne, IL (United States), 15-17 May 1995; Other Information: PBD: [1995]; Related Information: Is Part Of Thirteenth symposium on energy engineering sciences: Proceedings. Fluid/thermal processes, systems analysis and control; PB: 275 p.
- Country of Publication:
- United States
- Language:
- English
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