Ion beam assisted deposition of zirconium nitrides for modulated optical index structures

Zirconium nitrides reveal interesting optical and electrical properties whi ch highly depend on the nitrogen stoichiometry. Indeed, the material exhibi ts a transition from metallic ZrN (optical index for bulk at 633 nm: N = 0. 5-i3.2) to transparent insulator Zr3N4 (N = 3.2- i0.2). This work deals wit h the controlled elaboration of homogeneous ZrN-like and Zr3N4-like coating s. These have been prepared using reactive Dual Ion Beam Assisted Depositio n (IBAD) using a Zr target and N-2 or N-2 + Ar reactive gas. We particularl y studied the influence of different elaboration parameters (ion energy, ga s composition of the reactive beam and substrate temperature) on the nitrid es composition and on their optical and electrical properties. This study n ow allows a reproducible elaboration of different kinds of zirconium nitrid es which can lead to the realisation of an in-depth modulated optical index structure. (C) 1999 Elsevier Science B.V. All rights reserved.