The effect of ion bombardment on stress and adhesion in thin films of silver and aluminum

Abstract

A simple ion gun is described and results are given for the effect of bombardment with 50–70 keV Ar + and O 2 + ions on internal stress and adhesion in thin films of silver and aluminum evaporated onto glass substrates. Ion bombardment led to large compressive bending forces and stresses significantly exceeding in magnitude the values of the intrinsic stress found in these materials and to adhesion increases as measured by the scratch test. Both films stress and adhesion were found to increase linearly with ion dose up to 4 mC cm -2. Adhesion was found to increase with time in aluminium films but the increases became progressively smaller with increasing ion dose. No adhesion aging effects were observed in silver films.