Removal of barrier and liner layers from a bottom of a via

Abstract

A method for manufacturing a semiconductor device includes forming an interconnect in a first dielectric layer, and forming a second dielectric layer on the first dielectric layer. In the method, an etch stop layer is formed on the second dielectric layer, and a third dielectric layer is formed on the etch stop layer. A trench and an opening are formed in the third and second dielectric layers, respectively. A barrier layer is deposited in the trench and in the opening, and on a top surface of the interconnect. The method also includes removing the barrier layer from the top surface of the interconnect and from a bottom surface of the trench, and depositing a conductive fill layer in the trench and in the opening, and on the interconnect. A bottom surface of the trench includes the etch stop layer.