XPS INVESTIGATION OF THE A-CH/AL INTERFACE

The original state of the interface between ultrahard amorphous hydrogenated carbon (a-C: H) and aluminum was analyzed by non-destructive in-situ direct ion beam deposition (CH4, -400 V) as well as angle resolved XPS (X-ray photoelectron spectroscopy) analysis through a thin a-C: H coating. Depending on the deposition conditions a 0.6 to 1.9 nm thick Al4C3 interlayer, held responsible for the good adhesion between a-C:H and Al, could clearly be resolved. Furthermore, an interaction between a-C:H and Al4C3 at the a-C:H/Al4C3 interface was detected. The ability of C and Al to form a reactive Al4C3 interface as well as an interaction of a-C:H with Al4C3 has also been confirmed by XPS and AES sputter depth profile analysis.