A new method of forming a dual damascene interconnect is disclosed for manufacturing semiconductor substrates. A contact/via hole is first formed in a first dielectric layer formed over a substructure of a substrate having devices formed therein and/or metal layers formed thereon. The contact/via hole is filled with a protective material prior to forming a second dielectric layer. Conductive line opening is formed in the second dielectric layer and over the contact/via hole having the protective material in it. The protective material protects the edge of the contact/via hole from damage due to the second etching of the conductive line opening. Thus, a dual damascene structure is disclosed wherein the integrity of the edge of the contact/via hole is preserved, avoiding any reliability problems in the semiconductor product.