Preparation of High Adhesive Copper Film on Stainless Steel by Electron Shower

Copper-coated stainless steel is used in switches requiring a strong film in adhesion. The adhesion of the film prepared by electron shower was at least 100 times higher than that prepared by conventional thermal vapor deposition. To obtain a film with a high adhesion, we irradiated an electron shower on the substrate before evaporating the copper, which enhanced the formation of chromium oxide on the surface of the stainless steel substrate. The highly adhesive copper film was to form copper oxide with the oxygen atoms of the chromium oxide, but the thermal diffusion effect on adhesion was low, because thermal diffusion of copper was suppressed by chromium oxide. When the substrate was contaminated by carbon and chromium carbide formed instead of chromium oxide, no adhesive film could be formed, even with the use of the electron shower.