Abstract: A method for forming a carbon doped copper layer, preferably an electrochemically deposited carbon doped copper layer over a semiconductor structure, comprising the following steps. A semiconductor structure having an upper surface is provided. The semiconductor structure is placed in an electrochemical bath having a predetermined concentration of carbon. A first carbon doped copper layer is electrochemically deposited for a first period of time at a first current density. The first carbon doped copper layer blanket fills the semiconductor structure and has a predetermined thickness and a first concentration of carbon. A second carbon doped copper layer is electrochemically deposited over the first carbon doped copper layer for a second period of time at a second current density. The second carbon doped copper layer has a predetermined thickness and a second concentration of carbon.