Via bottom copper/barrier interface improvement to resolve via electromigration and stress migration

摘要

A method of forming a copper/barrier layer interface comprising the following sequential steps. A structure having a lower copper layer formed thereover is provide. A patterned dielectric layer is formed over the lower copper layer. The patterned dielectric layer having an opening exposing a portion of the lower copper layer. The exposed portion of the lower copper layer is converted to a copper silicide portion. A barrier layer is formed upon the patterned dielectric layer and the copper silicide portion, lining the opening, whereby the lower copper layer/barrier layer interface is formed such that the barrier layer contacts the copper silicide portion to form an interface.