Thermochemistry of Hydrocarbon Decomposition and Relationship to Properties of PECVD Diamond Films
Final rept. 1 Nov 88-31 Jan 91,
CRYSTALLUME MENLO PARK CA
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Considerable empirical research has been performed in the field of diamond film growth over the past fifteen years. However, this approach has proven insufficient in optimizing the deposition process. Also, no deposition mechanism has become universally accepted. A combination of in situ plasma diagnostic instruments, diamond film characterization, and computer modeling has been used to produce a self-consistent model of diamond-producing DC plasmas and to optimize the deposition process in terms of bonding type i.e., graphite vs. diamond and growth rate. The effects of important deposition parameters including methane concentration in hydrogen, current, electrode spacing, and pressure on both film and plasma characteristics have been analyzed. The presence of a negative electric field at the anode or substrate electrode has been determined to be necessary for the growth of high quality diamond films. The magnitude of this field is strongly dependent on pressure. Control of this field will be possible by monitoring with a Langmuir probe and controlling pressure, leading to in situ process control.
- Physical Chemistry