Adhesion improvement between metal thin films (Cu and Pt) and high surface free energy polyimide by ion assisted reaction

Adhesions between metal films (Cu and Pt) and polyimide substrate were enhanced by ion assisted reaction using low energy ion beams (~1 kV) in oxygen gas environments. In the ion assisted reaction process, ion dose and blown gas flow rate were changed from 5×10¹⁴ to 1×10¹⁷ ions/cm² and from 0 to 8 sccm, respectively. Surface free energy of polyimide film increased from 46 to 72 dyne/cm² by ion assisted reaction. The modified polyimide surface was observed by scanning electron microscopy and X-ray photoelectron spectroscopy, and electronegative groups such as C-O and C=O were formed on the polyimide surface without surface damage. Adhesion enhancement between metal films and polyimide modified by ion assisted reaction was confirmed by a peel test using scotch tape and a boiling test