Growth Rate and Surface Free Energy of Diamond Films Using Different Gas-Sources

For diamond multilayer structure film (low residual stress and good toughness), the monolayer thickness and surface properties have an important effect on the quality of multilayer film. Therefore, the influence of deposition parameters on the quality, growth rate and surface free energy of diamond films was investigated in CH4/H-2, CH4/H-2/Ar and CH4/H-2/N-2 respectively. The results show that the nano-crystalline diamond films can be prepared in three different gas sources. The growth rate significantly increases with increasing CH4 and N-2 content, but it increased at first and then decreased with increasing the Ar content. Surface roughness shows a downward trend with increasing of CH4 and Ar, as well as the addition of N-2. The surface free energy decreases with the decrease of the surface roughness and film purity. Finally, the average growth rate and surface free energy of the nano-crystalline diamond film can be controlled by adjusting the deposition parameters.