Copper films were deposited by evaporation onto aluminal substrates that had been sputtered to various doses with 500 eV ions. The adhesion strength of the films was measured with a pull-type adhesion tester. The adhesion of Cu to solvent-cleaned surfaces was low, but argon ion sputter cleaning produced adhesion near 80 MPa, and adhesion after oxygen ion bombardment was even better. Exposing the alumina to argon-oxygen plasma discharge (approximate to 40 eV ions) from the Kaufman-type ion source increased the adhesion beyond approximate to 55 MPa. The applicability of Weibull statistical analysis to the distribution of pull test data for solvent-cleaned rough alumina was investigated. A good fit of the data to the Weibull expression was observed, with zero apparent threshold strength and a low Weibull modulus of approximate to 2.9.