Sputtering of graphite-like BN crystals

The sputtering of hexagonal and rhombohedral forms of boron nitride is studied by computer simulation and experimentally. The sputtering yield of the rhombohedral crystal is found to be up to twice as large as that of the hexagonal one in the energy range of Ar+ ion bombardment from 0.3 to 4 keV. For both types of BN, boron is sputtered more easily than nitrogen. Computer calculated spatial and energy distributions of the particles sputtered from the (0001) face of a BN single crystal are studied. Spatial distributions exhibit preferential sputtering of B and N atoms in particular directions. These atoms form three distinct spots for each of the two components; the patterns for B and N are turned through an angle of 60° with respect to each other. Features of the backward and forward sputtering from a target containing a different number of the (0001) layers, as well as the mechanisms of particles ejection are discussed.