| abstract |
Structures and methods for fabrication of an under bump metallization (UBM) structure having a metal seed layer and electroless nickel deposition layer are disclosed involving a UBM structure comprising a semiconductor substrate, at least one final metal layer, a passivation layer, a metal seed layer, and a metallization layer. The at least one final metal layer is formed over at least a portion of the semiconductor substrate. Also, the passivation layer is formed over at least a portion of the semiconductor substrate. In addition, the passivation layer includes a plurality of openings. Additionally, the passivation layer is formed of a non-conductive material. The at least one final metal layer is exposed through the plurality of openings. The metal seed layer is formed over the passivation layer and covers the plurality of openings. The metallization layer is formed over the metal seed layer. The metallization layer is formed from electroless deposition. |