| abstract |
(57) [Abstract] [Purpose] When etching a barrier metal, the process of bump formation is simplified without the need to protect the bump with a photosensitive resist, and the barrier metal to be etched is larger than the size of the bump. Without doing so, even if the distance between adjacent bumps becomes narrower, short-circuiting is not performed and bumps of higher density are formed. [Structure] The entire surface of the wafer in which the electrode pad portion of the semiconductor element is exposed and the other portion is covered with a passivation film A barrier metal is deposited in the order of i and Cu, and then a photosensitive resist is applied and developed to open a pad portion, then a solder bump is plated in the opening portion, and then the photosensitive resist is removed, and A bump formation method that removes barrier metal except under solder by etching with a single solution. |