MECHANICAL CHARACTERIZATIONS OF NITRIDE FILMS DEPOSITED BY ION-BEAM BASED TECHNIQUES

Many potential applications of deposited BN and SiN, such as for wear- resistant coatings or optical layers, are limited by the intrinsic str ess in thin films which can be high enough to cause severe problems. I n ion beam assisted deposition (IBAD) boron nitride and reactive ion b eam sputtering deposition (RIBSD) boron and silicon nitride layers, th e internal stress can always be reduced below -1 GPa by a post-deposit ion annealing. When the deposition temperature is varied up to 600 deg rees C, the stress in RIBSD Si3N4 layers is not significantly reduced and, for IBAD BN films, it is even greater than expected from the deve lopment of the thermal stress. These results suggest that at 500 eV th e spatial extent of the ion peening effect may largely exceed the pene tration depth of ions and of recoil atoms in the solid. The observed d ifference in behavior between RIBSD films and IBAD ones is probably du e to the higher incident energy during IBAD deposition. (C) 1997 Elsev ier Science S.A.