Characterization of laser-arc deposited multilayer systems by means of AES, Factor Analysis and XPS

In a vacuum chamber at 5x10(exp -4) Pa, multilayer systems (single layer thickness 20 nm) consisting of Ti/C and Al/C, respectively, have been deposited on Si (1 1 1) disks by the laser assisted coating (Laser-Arc). Structure and composition have been investigated by means of Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Auger Electron Spectroscopy (AES) in conjunction with Factor Analysis. AES depth profile measurements through the outermost part of the layers show for both the Ti/C and the Al/C samples a regular structure of the layer sequence metal/ carbon with a constant distance along the sample normal and sharply formed interfaces. In the metallic layers an oxygen enrichment was found, which is more intensive in the Ti/C deposit than in the Al/C one. By means of Factor Analysis in the evaluation of the differentiated spectra as a function of sputtering time, the formation of carbides at the metal/carbon interfaces has been detected. However, in t he present state of the investigations it can not be decided, whether the observed carbide formation is the result of the energy impact due to ion sputtering or the coating fabrication process itself.