Under ball metallurgy (UBM) for improved electromigration

摘要

An interconnect structure that includes a substrate having an electrical component present therein, and a under-bump metallurgy (UBM) stack that is present in contact with a contact pad to the electrical component that is present in the substrate. The UBM stack includes a metallic adhesion layer that is direct contact with the contact pad to the electrical component, a copper (Cu) seed layer that is in direct contact with the metallic adhesion layer, a first nickel (Ni) barrier layer that is present in direct contact with copper (Cu) seed layer, and a layered structure of at least one copper (Cu) conductor layer and at least one second nickel (Ni) barrier layer present on the first nickel (Ni) barrier layer. A solder ball may be present on second nickel (Ni) barrier layer.

主权项

1. A method of forming an interconnect structure comprising:
forming a metallic adhesion layer on a contact pad to an electrical component that is present in a substrate; forming a copper (Cu) seed layer on the metallic adhesion layer; forming a barrier layer in direct contact with the copper (Cu) seed layer, wherein the barrier layer protects the copper (Cu) seed layer from reacting with later formed metallic layers and is selected from the group consisting of titanium (Ti), a Ti-cobalt (Co) alloy, a Ti—Ni alloy, a Ti—Co—Ni alloy and a Ni—Ti alloy; forming a copper (Cu) conductor layer on the barrier layer; and forming a solder ball atop the copper conductor layer.