A semiconductor structure and methods of forming the same are provided. The semiconductor structure includes a semiconductor substrate; a first inter-layer dielectric (ILD) over the semiconductor substrate; a contact extending from a top surface of the first ILD into the first ILD; a second ILD over the first ILD; a bottom inter-metal dielectric (IMD) over the second ILD; and a dual damascene structure comprising a metal line in the IMD and a via in the second ILD, wherein the via is connected to the contact.