Chromium/chromium nitride multilayers during thermal treatment: An X-ray diffraction study

Chromium/chromium nitride multilayer coatings consisting of a stack of alternating 82nm thick chromium and 168nm thick CrNx sublayers with a total thickness of 4μm were deposited on silicon wafers by magnetron sputtering below 70°C. X-ray diffraction revealed for the as-deposited state a significant fraction of material in amorphous state. The effect of subsequent heat treatment on the formation of the crystalline phases Cr and Cr2N, on the coherent diffracting length of the occurring crystallites, as well as the correlated variations of the lattice cell parameters was studied by in-situ high temperature X-ray diffraction techniques. Ex-situ observations of the crystallographic texture showed the presence of a fibre texture parallel to the [1 0 0] direction for the Cr-phase and a fibre texture parallel to the [1 1 2] direction for the Cr2N phase.