Barrier layer for copper interconnect

摘要

A copper interconnect includes a copper layer formed in a dielectric layer. A glue layer is formed between the copper layer and the dielectric layer. A barrier layer is formed at the boundary between the glue layer and the dielectric layer. The barrier layer is a metal oxide.

主权项

1. A method comprising:
etching a dielectric layer to form an opening; depositing a glue layer to a bottom and sidewalls of the opening, wherein the glue layer comprises a metal alloy; depositing a seed layer over the glue layer; after the depositing the seed layer, filling the opening with a metallic material; and performing a thermal treatment to cause a metal in the seed layer to diffuse through the glue layer, wherein the metal reacts with the dielectric layer to form a barrier layer.