Enhanced Cu-Teflon adhesion by presputtering treatment: Effect of surface morphology changes

The recently observed enhancement in adhesion between Cu and Teflon due to a presputtering treatment of Teflon prior to the Cu deposition is analyzed. The sputtering treatment resulted in a morphology change of the Teflon, with the deposited Cu showing similar textures, and changes in chemical bondings between the two. A simple geometric model is used to analyze the contribution from the morphology changes to the observed peel strength. It is shown that, for a finite chemical bonding, an appreciable contribution to the peel strength is possible from the morphology changes observed.