Abstract: The present description relates to a method of manufacturing an end of an interconnection structure of an integrated circuit, the method including: providing an integrated circuit including an interconnection structure including copper interconnection elements at least partly extending through an insulating layer and flush with a first surface of said interconnection structure; forming a protection layer on the first surface of the interconnection structure, said protection layer including a material adapted to protecting the copper of the interconnection elements; forming a passivation layer on the protection layer, the passivation layer having a first thickness; and forming a first opening in the passivation layer across a second thickness smaller than the first thickness, to keep a residual passivation layer at the bottom of the first opening.