LAYERED GROWTH OF BORON-NITRIDE THIN-FILMS

Thin boron nitride films were deposited using ion beam assisted deposi tion. The fraction of the cubic phase relative to the non-cubic phase was varied by changing the assisting ion to boron atom arrival ratio d uring deposition. Different ex situ analytical techniques were used to resolve the layered growth, i.e. cubic BN on top of non-cubic BN. Var iation of the argon incorporation measured with Rutherford backscatter ing spectroscopy yields information on the layered growth. Polarized I R reflection data were analysed with a multilayer model taking into ac count the anisotropy of hexagonal BN. The parameters of the optical mo del, such as the thickness of the non-cubic BN interlayer and the volu me fraction of cubic BN in the toplayer, are more useful for the chara cterization of BN films than the established IR peak ratio. Reflection electron energy loss spectroscopy and X-ray reflectivity measurements were also performed to verify the results. (C) 1997 Elsevier Science S.A.