Electron optical characterization of cubic boron nitride thin films prepared by reactive ion plating

Abstract

Boron nitride films prepared by reactive ion plating from a boron evaporation source were characterized structurally using three independent electron optical techniques: energy filtered electron diffraction with radial distribution function analysis; electron energy-loss spectroscopy of the near-edge structure of the boron K edge; and spectroscopy of the plasmon region of the energy-loss spectrum. Both specimens had a graded BNx layer between the BN layer and the silicon substrate and in addition one specimen had a titanium bonding layer underneath the BNx layer. The presence of c-BN in both specimens was confirmed by all techniques. The specimen with the titanium bonding layer was examined in cross section and showed essentially pure c-BN on the surface. A model for the formation of c-BN assisted by the compressive stress generated during deposition is proposed.