| abstract |
The invention relates to a method for forming high sp 3 content amorphous carbon coatings deposited by plasma enhanced chemical vapor deposition on internal surfaces and employing the “hollow-cathode” technique. This method allows adjustment of tribological properties, such as hardness, Young's modulus, wear resistance and coefficient of friction as well as optical properties, such as refractive index. In addition the resulting coatings are uniform and have high corrosion resistance. By controlling pressure, type of diamondoid precursor and bias voltage, the new method prevents the diamondoid precursor from fully breaking upon impact with the substrate. The diamondoid retains sp 3 bonds which yields a high sp 3 content film at higher pressure. This enables a faster deposition rate than would be possible without the use of a diamondoid precursor. |