Effects of Carbonization of Filaments on CVD Diamond Thick Films Prepared by HFCVD Method

Hot filament CVD method has many advantages such as simple equipment, easy operation and low expenses, which make it the most widely used method in industrial producing diamond thick film. In this paper, tantalum filament is used in the hot filament chemical vapor deposition apparatus to carbonize under different temperature for different time, then nucleation experiments are carried out on molybdenum substrate. SEM and EDS are used to observe the surface morphology and analyze the components of the carbonized filament and substrate. The results show that lasting the carbonization time can improve the nucleation density in preparing diamond thick film,the adhesion of the diamond film also increases. Electrical resistance of the filament after carbonization can be used as a criterion to determine whether it is fully carbonized or not.