Metal pillar bump structure and method of forming same

The present invention discloses a metal bump formed and column structure, the method comprising: forming a protective layer on a semiconductor substrate; forming a conductive layer on the protective layer; providing a patterned and etched in a resist layer on the conductive layer, the resist layer is defined with at least one opening; depositing a metal layer in the at least one opening; along one or more interposed between the resist layer and the metal layer the resist layer is etched portion of a screen, to form a plurality of pockets; depositing a solder material in the at least one opening, the solder material is filled within a plurality of said pockets and above the metal layer in the opening the inner portion; removing the remaining resist layer and the conductive layer is not formed under the metal layer; and reflowing the solder material to cover the metallic layer. The present invention may be protected during the manufacturing process of the bump metal pillar sidewalls.