ARXPS - STUDIES OF NUCLEATION AND MAKE-UP OF SPUTTERED TIN-LAYERS

Hardness, high density and small crystal size of sputtered TiN coatings yield protective layers, with, e.g., enhanced wear resistance. The properties of these layers depend crucially on their chemical and structural state and their bonding to the substrate. By simultaneously fitting XPS spectra obtained for take-off angles between 10-degrees and 70-degrees not only an enhanced resolution but also a new dimension - the depth resolution - is gained. So, small amounts (< 0.5 nm) of interface compounds are identified in level shift, stoichiometry and spatial distribution in the top 10 nm. For TiN sputtered onto Mo the ARXPS-analysis revealed that the TiN growth is nucleated by MoTixNy as bonding, metallic interface layer. On MoTixNy textured TiN grows with metallic oxinitride TiN0.8O0.2 precipitating at the surface. These cristallites (almost-equal-to 0.1-mu-m) are coated by TiN0.5O0.5 (almost-equal-to 1 nm) and Ti2O3-TiO2 (almost-equal-to 7 nm) and covered by CHx-OH adsorbates. Problems with the quantitative XPS analysis of TiN are discussed and related to intrinsic plasmon satellites.