Structural, mechanical and optical properties of t(x)a-C(1-x) deposited by a filtered cathodic arc

The primary objective of this study is to determine how the process parameters effect the properties of doped and undoped tetrahedrally bonded amorphous carbon (t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}){dollar} deposited by the filtered cathodic arc. The microstructure of the t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}{dollar} coatings is characterized by transmission electron microscopy (TEM). Parallel electron energy loss spectroscopy (PEELS) and Raman spectroscopy is used to characterize the bonding. The mechanical and optical properties were determined for t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}{dollar} coatings deposited on flat substrates such as Si and sapphire.; Our group found that t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}{dollar} films deposited on 3-dimensional objects produced a columnar microstructure. To gain insight into the microstructural, mechanical and optical properties of this 3-dimensional coating, films were deposited on flat (111) Si wafers at various deposition angles. It was found that the incident angle of the carbon vapor stream was a key parameter in the formation of the columnar microstructure. The columns were linked to an increase in sp{dollar}sp2{dollar} content in the films. This increase led to a decrease in the stress, hardness and band gap of the t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}{dollar} films. A qualitative model has been proposed correlating the process parameters to the formation of these columns and how they are associated with the bonding in the t{dollar}sb{lcub}rm x{rcub}{dollar}a-C{dollar}sb{lcub}rm 1-x{rcub}{dollar} films.