Ion Implantation Induced Modifications in Reactively Sputtered Cr-N Layers on Si Substrates
We present a study of the micro-structural changes induced in Cr-N layers by irradiation with argon ions. The layers were deposited by reactive ion sputtering on (100) Si wafers, to a thickness of 240-280 nm, at different nitrogen partial pressures and different substrate temperatures. The samples were subsequently irradiated with 120 keV Ar+, to 1x1015 and 1x1016 ions/cm2. Structural characterization was performed with Rutherford backscattering spectroscopy, x-ray diffraction analysis and transmission electron microscopy, and we also did electrical resistivity measurements on the samples. It has been found that the layers grow in the form of a polycrystalline columnar structure, with a columnar width of a few tens of nm. The layer composition, Cr2N or CrN, strongly depends on the nitrogen partial pressure during deposition. Ion irradiation induces local micro-structural changes, formation of nano-particles and defects, though the structures retain their polycrystalline nature. The induced crystalline defects yield an increase of electrical resistivity after ion irradiation.
Dragan P. Uskoković, Slobodan K. Milonjić and Dejan I. Raković
M. Novaković et al., "Ion Implantation Induced Modifications in Reactively Sputtered Cr-N Layers on Si Substrates", Materials Science Forum, Vol. 555, pp. 35-40, 2007