Neutron reflectivity investigation of the effects of harsh environments onTa2N thin films

We use neutron reflectivity to study the effects of harsh environments on t he composition and structure of Ta2N films. We investigated samples with a 700 Angstrom Ta2N layer, annealed in vacuum, hydrogen, and air, in an attem pt to simulate the effects of aging on Ta2N thin films. We obtained good mo del/data fits for all samples studied, with the exception of the air anneal ed sample - inhomogeneities and cracking reduced the quality of this fit. A 90 Angstrom thick layer of TaHx was found on top of the hydrogen annealed sample, with no evidence of hydrogen enrichment at the Ta2N/SiO2 interface. Furthermore, we found that air annealing produces a similar to 2000 Angstr om thick layer of tantalum oxide. (C) 1999 Elsevier Science S.A. All rights reserved.