Structural analyses of carbon films deposited at different total mass rates in a hot-filament CVD system

Abstract

Depositing carbon films rich in the diamond phase was carried out in many studies. However, characterization of the deposited carbon films does not reveal up-to-date information about the structure at all scales. In this work, we deposited carbon films on silicon substrates. To deposit carbon films using a hot-filament chemical vapor deposition technique, the selected total mass flow rates were 200, 300, and 400 sccm. The CH₄ concentration was kept constant at 1.5% in all the experiments. The carbon films deposited mainly in the diamond phase show different structures at different total mass flow rates. At 400 sccm, there is a maximum growth rate. The X-ray investigations show that the carbon films were mainly deposited in the diamond and graphite composite structure. Different X-ray peaks are related to the electronic configurations of the graphitic and diamond atoms forming the top-layered surface in a carbon film. The carbon films deposited at different total mass flow rates present new science and engineering. The possible application of the deposited carbon films is also studied. Due to uncertainties in previous studies, the current work strongly suggests re-investigations of the deposition and characterization of carbon films. The results from both the X-ray analysis and field-emission scanning electron microscopy agree with each other. The current study discusses the new underlying science of carbon films. This should, therefore, be exciting and essential for the readers. The study also introduces a new engineering method.