A dual damascene process is disclosed. A substrate having a base dielectric layer, a lower wiring layer inlaid in the base dielectric layer, and a cap layer capping the lower wiring layer is provided. A dielectric layer is deposited on the cap layer. A silicon oxide layer is deposited on the dielectric layer. A metal hard mask is formed on the silicon oxide layer. A trench opening is etched into the metal hard mask. A partial via feature is etched into the dielectric layer within the trench opening. The trench opening and the partial via feature are etch transferred into the dielectric layer, thereby forming a dual damascene opening, which exposes a portion of the cap layer. A liner removal step is performed to selectively remove the exposed cap layer from the dual damascene opening by employing CF4/NF3 plasma.