Deposition And Characterization Of Fullerene-like Hydrogenated Amorphous Carbon Films

Fullerene-like structure hydrogenated amorphous carbon films were prepared with plasma chemical vapor deposition technique.Through the adjustment of the growth and post treatment parameters,the correlation between the structure and properties of the fullerene-like carbon films was studied,and the volume of fullerene-like microstructure in the films was controlled.Meanwhile,the formation mechanism of fullerene-like microstructure was discussed.The main contents of the thesis include:1.Fullerene-like hydrogenated amorphous carbon films were deposited using dc-pulse plasma chemical vapor deposition.The fullerene-like structre hydrogenated carbon films demonstrated higher hardness and elastic recovery than the hydrogenated amorphous carbon film deposited with conventional plasma enhanced chemical vapor deposition.2.The volume of fullerene-like microstructure was controlled with growth time,the content of hydrogen in the deposition process,and post treatment of annealing,etc. A new approach of fitting Raman spectra was introduced.The Raman spectra of as-deposited films were decomposed into four Gaussian peaks as opposed to the traditional D and G peak,and the volume of fullerene-like microstructure was analyzed according to odd rings content.The mode a:the fullerene-like hydrogenated carbon films annealed in vacuum showed excellent mechanical and tribological properties,which is inconsistent with the conventional hydrogenated amorphous carbon films.The mode b:the relationship between the volume of fullerene-like microstructure and the corresponding hardness and elastic recovery property was obtained.The mode c:Due to the presence of the fullerene-like structure,the as-deposited films showed lower stress,higher hardness and elastic recovery properties.3.In contrast with conventional hydrogenated amorphous carbon film,hydrogenated amorphous carbon films with thickness about 2μm and stress lower than 1GPa were deposited using dc-pulse plasma chemical vapor deposition.A new model was proposed for stress relief.As Ar was introduced into reaction,the films with different stress relief patterns were prepared,and the correlation between stress relief pattern and film structure was studied.Meanwhile,the carbon nitride film prepared with tic-pulse plasma chemical vapor deposition exhibited lower stress without hardness loss as Ar was introduced.4.The formation mechanism of fullerene-like microstructure was studied.Firstly, the formation mechanism of fullerene-like microstructure at the beginning of film growth was studied.Secondly,the formation mechanism of fullerene-like microstructure at different growth time was studied when the film was too thicker to consider the effect of substrate.The substrate effect and heat accumulation took the main role at 0.5h and 2h for the formation of fullerene-like microstructure, respectively.