RADIOFREQUENCY HOT-FILAMENT CVD OF DIAMOND

In the present study diamond films have been deposited by radio-frequency hot-filament chemical vapour deposition (CVD). The RF energy was capacitively coupled to the electrode through a matching network. A wolfram hot filament source of electrons activating the sp3 states in carbon atoms was placed above the electrode. The wolfram filament was self-biased. Hydrogen with a small addition of methane, or methane only, was used as a reactive gas. The polycrystalline smooth diamond films were grown on the substrates, which were placed under the hot filament electron source. Without electrons, amorphous carbon was deposited. The main difference between this new RF HF CVD method and other HF CVD techniques is the relatively low temperature of the substrates. One should also emphasize that it is possible to obtain a diamond phase by the RF HF CVD method using only methane, without hydrogen. © 1992.