CORRELATION BETWEEN MICROSTRUCTURE AND COLLISIONAL EFFECTS IN CUBIC BORON-NITRIDE SYNTHETHIZED USING IBAD

Polycrystalline cubic BN films have been synthetized by IBAD. The bulk of the films is constituted of randomly oriented sp(3) crystallites, whereas the surface is sp(2) bonded. In order to correlate the microst ructure with the collisional effects, computer simulations using TRIDY N have been performed for three deposition threshold conditions. The c omputed spectra of recoil energies transferred to deposited atoms in t he growing film and the in-depth distributions of collisions have been correlated to the c-BN content for various primary ion energies. The results suggested a root E - E(0) dependence for the c-BN synthesis wh ich agrees with both the root E dependence proposed by Kester and Mess ier at high energy and the sputtering yield dependence proposed by Rei nke and coworkers at low energy. At the surface itself, direct knock-o n collisions take place leading to the surface sp(2)-bonded zone.