| 摘要 |
<p>PURPOSE:To facilitate the etching of an intermediate metal layer, and prevent the formation of an oxide film on said layer surface by a method wherein the intermediate metal layer is formed of a first metal film for bonding, a second metal film whose main component is copper, and a third metal film for preventing oxidation, and the second and the third metal films are mutually diffused and transformed into an alloy film by heat treatment after bump formation. CONSTITUTION:An Al pad 3 is formed by depositing an Al layer arranged on an interlayer insulating film 2 arranged on a semiconductor substrate 1. In order to form an intermediate metal layer on the surface containing an aperture part 5, a titanium film 6 as a first metal film, a copper film 7 as a second metal film, and a gold film 8 as a third metal film are laminated. The above intermediate metal layer improves the adhesion between the pad 3 and a bump, and forms a barrier. After a photo resist film 9 is formed, patterning is performed, and an aperture 5A, which is a little larger than the aperture 5, is formed to expose the gold film 8 of the intermediate metal layer. Gold is deposited on the gold film 8 by electroplating method, and a bump 10 is formed. By heat treatment in nitrogen atmosphere, the gold film 8 and the copper film 7 are mutually diffused to form an alloy film 11. The alloy film 11 and the titanium film 6 are etched and eliminated.</p> |
