Methods of manufacturing semiconductor devices

A method for manufacturing a semiconductor device comprising:

• forming a trench in an interlayer dielectric through a dual damascene process;
• depositing a barrier metal layer directly on an overall surface of the interlayer dielectric and the trench, the barrier metal layer preventing diffusion of copper;
• depositing a copper layer in the trench;
• planarizing the copper layer to form a copper line, wherein the barrier metal layer on the interlayer dielectric is removed;
• performing a wet etching process to remove a top portion of the copper line, wherein the barrier metal layer within an upper portion of the trench is removed;
• depositing a dielectric barrier layer on the etched copper line;
• and
• performing a planarization process to flatten the dielectric barrier layer such that the top surface of the dielectric barrier layer is formed on a same horizontal plane with the top surface of the interlayer dielectric,
• wherein the lower surface of the dielectric barrier layer is formed directly on the copper line and the barrier metal layer, and
• wherein the side surface of the dielectric barrier layer directly contacts the interlayer dielectric.