Extensive studies on the relationship between a copper thin film and its polyimide substrate show that the adhesion strength is very weak. In this work, we show how to reduce Cu film resistivity and improve the adhesion strength between Cu and polyimide. After nitrogen and oxygen plasma treatment, polyimide substrates can substantially improve the resistivity and adhesion strength deposited Cu. It is found that the lowest resistivity is 4.22 mu Omega cm and the maximum adhesion strength is 72.23 MPa for a polymide substrate treated in oxygen plasma for 5 min. (c) 2005 Published by Elsevier B.V.