Copper pillar bump having annular protrusion
AssigneeShinko Electric Industries Co., Ltd.
InventorsKengo Yamamoto, Daisuke Ito, Mitsuaki Okubo, Kenji Uchida
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Abstract
A copper pillar bump for an electrode pad of a semiconductor chip includes a first copper layer, a first metal layer formed directly on the first copper layer, a second copper layer formed directly on the first metal layer, and a second metal layer formed directly on the second copper layer, wherein the first metal layer and the second metal layer are made of a metal having a different etching rate than copper, wherein an outer perimeter ring of the first metal layer protrudes beyond a lateral surface of the first copper layer, and wherein an outer perimeter ring of the second metal layer protrudes beyond a lateral surface of the second copper layer.
Claims11
A copper pillar bump for an electrode pad of a semiconductor chip, comprising:
- a first copper layer;
- a first metal layer formed directly on the first copper layer;
- a second copper layer formed directly on the first metal layer;
- and
- a second metal layer formed directly on the second copper layer,
- wherein the first metal layer and the second metal layer consist of a same material, the material including a metal having a different etching rate than copper,
- wherein an outer perimeter ring of the first metal layer protrudes beyond a lateral surface of the first copper layer, and
- wherein an outer perimeter ring of the second metal layer protrudes beyond a lateral surface of the second copper layer.
Dependencies are inferred from the claim text.