CVD diamond growth: Replacing the hot metallic filament with a hot graphite plate

A diamond film was synthesized by chemical vapor deposition, where a hot graphite plate was used to thermally activate methane and hydrogen. The effect of parameters on the diamond films grown, such as pressure ranging from 40 to 100 torr, methane concentration in hydrogen varying from 0.5 to 2 vol %, and substrate temperatures from 1020 to 1140 degrees C, were studied. Diamond films with nanocrystalline to polycrystalline crystal sizes were obtained. A maximum growth rate of 0.8 mu m/h was obtained, and the quality is comparable to diamond films synthesized by the hot metal filament chemical vapor deposition method. In contrast to the hot filament method, this method does not use a metallic filament as thermal activator. Therefore, the diamond films contain no metal contaminants and thus can be used for electronic and biomedical applications. The absence of metal contaminants was confirmed using different methods. (C) 2021 Elsevier Ltd. All rights reserved.