High fluence nitrogen implantation in Al/Ti multilayers

We have studied the effects of high fluence nitrogen ion implantation on the structural changes in Al/Ti multilayers, with the aim of achieving multilayered metal-nitrides. The starting structures consisted of 10 alternate sputter-deposited Al and Ti films, with a total thickness of 270 nm, on (100) Si substrates. They were implanted with 200 keV N-2(+), to 1 x 10(17) and 2 x 10(17) at/cm(2), the projected range being around half-depth of the multilayers. Structural characterization was performed by Rutherford backscattering, Auger electron spectroscopy and transmission electron microscopy. It was found that ion implantation to the higher fluence induces a full intermixing of Al/Ti layers, resulting in a multilayered structure with different content of Al, Ti and N. The applied method can be interesting for preparation of graded (AI,Ti)N multilayers, with a controlled content of nitrogen and a controlled level of Al-Ti intermixing within the structures. (C) 2008 Elsevier B.V. All rights reserved.