| The effect of deposition variables in DC PACVD method on diamond synthesis was investigated. The main variables were deposition temperature, pressure, methane and oxygen concentration. Plasma characteristics of DC PACVD used in this study was close to those of thermal plasma owing to the high deposition pressure around 200Torr. This could make the growth rate and the diamond quality better than other low pressure deposition method. The film thickness increased linearly with time. Similar to the previous result, the growth rate increased with increasing methane, or decreasing oxygen concentration. The maximum methane concentration showing a clear diamond crystal facet appeared to be above 4%. The crystallinity of diamond depended on both methane and oxygen concentration. However, even at high methane concentration of 4%, the full width at half maximum(FWHM) value of diamond peak has shown a value smaller than those at lower methane concentrations, This was due to a difference in the growth plane. Other variables such as temperature, pressure etc., also affected the deposition characteristic, but with a less degree. |
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