Depth profiling of heavy-ion-mixed TiN films

A survey is given on the modifications of 30–300 nm thin TiN films on various substrates under high-fluence irradiation with 80–700 keV Ar, Kr and Xe ions. In particular, the effects of sputtering, interface mixing and blister formation were investigated. The results were obtained by combining several depth-profiling techniques, such as resonant nuclear reaction analysis (RNRA), Rutherford backscattering spectroscopy (RBS) and proton-induced X-ray emission (PIXE). Scanning electron microscopy and adhesion tests were also applied to the films. Optimal interface mixing parameters are proposed on the basis of the measured sputtering and mixing rates.     

PIXE measurements of Kr-sputtered TiN coatings

Titanium nitride films of 30–300 nm thickness deposited via dc magnetron sputtering were irradiated with 150–700 keV Kr ions at fluences up to 2.1 × 10¹⁷ cm⁻². These films were then scanned with a well-collimated 400 keV proton beam and the X-ray yield of Ti was measured both in and outside the Kr beam spot. This procedure results in a precision determination of the average film thickness (± 1% in the case of tens of nm films). The PIXE results are found to be consistent with RBS data of the same specimens. Sputtering yields were determined from the variation of X-ray yields assuming unchanged Ti/N stoichiometry in the implanted area. For thick TiN films (d₀ > 100 nm) the sputtering yields are in good agreement with predictions of the collisional cascade model by Sigmund. In contrast, sputtering of thin layers (d₀ = 30 nm) depended sensitively on the ion energy, being a factor of 2 higher at 150 keV than at 500 keV.