Transmission electron microscopic study of c -BN films deposited on a Si substrate

Microstructure of c-BN films synthesized by the ion-plating method were observed and characterized by high resolution electron microscopy and microdiffraction. The c-BN films of ∼0.2 μm thickness were deposited on top of ∼0.05 μm of h-BN, which was oriented with its c-axis parallel to the substrate. Lattice image taken along the 〈011〉 direction showed that c-BN film was well crystallized with an interplanar distance ∼2.1 Å, although the grain size was extremely small, from 5 to 20 nm. Further, the microdiffraction pattern along the 〈011〉 direction by focusing the electron beam to ∼20 Å, clearly showed that the small grains consisted of a single crystal of c-BN.