Control of stress and delamination in single and multi-layer carbon thin films prepared by cathodic arc and RF plasma deposition and implantation

The build-up of intrinsic stress in carbon thin films deposited by vapour deposition is a major cause of delamination. The delamination issue is one of the main reasons preventing wider applications of carbon vapour deposited films. In this work, we studied single and multilayer thin films of carbon and found that under certain deposition conditions, we were able to produce thin films free from delamination. Furthermore, we were able to stop film delaminating by adding a control layer. Two methods were used to deposit the carbon films: (1) filtered cathodic arc deposition with both negative DC and pulsed bias applied to the substrate and (2) RF plasma CVD with negative pulse bias up to 30 kV, 60 Hz, 100 μs. Both single and multilayer structures of carbon with different sp2 and sp3 ratios were deposited and it was found that, under controlled conditions, the overall stress was maintained at acceptable levels. Moreover, it was found that an additional control layer stopped ongoing delamination of the film. The structures of these multilayers were studied using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM).