An interconnect structure includes a dielectric layer, a first conductive feature, a hard mask layer, a conductive layer, and a capping layer. The first conductive feature is disposed in the dielectric layer. The hard mask layer is disposed on the first conductive feature. The conductive layer includes a first portion and a second portion, the first portion of the conductive layer is disposed over at least a first portion of the hard mask layer, and the second portion of the conductive layer is disposed over the dielectric layer. The hard mask layer and the conductive layer are formed by different materials. The capping layer is disposed on the dielectric layer and the conductive layer.