A device comprises a metal via having a lower portion in a first etch stop layer and an upper portion in a first dielectric layer over a substrate, a second etch stop layer over and in direct contact with the first dielectric layer, a second dielectric layer over and in direct contact with the first etch stop layer, a stress reduction layer over and in direct contact with the second dielectric layer, a third etch stop layer over and in direct contact with the stress reduction layer and a metal structure over the metal via, wherein the metal structure comprises a lower portion in the second etch stop layer and the second dielectric layer and an upper portion in the stress reduction layer, wherein a top surface of the metal structure is level with a top surface of the stress reduction layer.