ADHESION ENHANCEMENT OF THIN-FILM DEPOSITS BY CHOPPING

The chopping technique has been successfully used to enhance the adhes ion of MgF2, ZnS and copper films. Chopping does not appreciably alter the adhesion of aluminium and chromium films. Chopping seems to incre ase the surface mobility of adatoms and prevent growth of large crysta llites whereby producing more defect-free thin films because of higher relaxation leading to higher adhesion. The adhesion of chopped MgF2 a nd ZnS films compare well with those deposited on heated substrate and after glow discharge cleaning. The enhanced adhesion of copper films is being explained in terms of enhanced oxygen affinity at interface s imilar to that observed for aluminium and chromium. Chopping technique might provide a simple and cost effective process of depositing good adherent thin film coatings.