PIXE measurements of Kr-sputtered TiN coatings

Abstract

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 × 10 17 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 ( d 0 > 100 nm) the sputtering yields are in good agreement with predictions of the collisional cascade model by Sigmund. In contrast, sputtering of thin layers ( d 0 = 30 nm) depended sensitively on the ion energy, being a factor of 2 higher at 150 keV than at 500 keV.