COPPER STRUCTURES WITH INTERMETALLIC COATING FOR INTEGRATED CIRCUIT CHIPS

摘要

An integrated circuit (IC) chip includes a copper structure with an intermetallic coating on the surface. The IC chip includes a substrate with an integrated circuit. A metal pad electrically connects to the integrated circuit. The copper structure electrically connects to the metal pad. A solder bump is disposed on the copper structure. The surface of the copper structure has a coating of intermetallic. The copper structure can be a redistribution layer and a copper pillar that is disposed on the redistribution layer.

主权项

1. A method of manufacturing an integrated circuit (IC) chip, the method comprising:
forming a copper seed layer over a substrate, the copper seed layer being formed to electrically connect to a metal pad that electrically connects to an integrated circuit in the substrate; electroplating a first copper layer on the copper seed layer; electroplating a second copper layer on the first copper layer; electroplating solder on the second copper layer; electroless plating a coating of tin on a surface of the first copper layer, the second copper layer, and the solder; and heating the coating of tin to form a tin-copper intermetallic coating on the surface of the first copper layer and the second copper layer.