SEMICONDUCTOR STRUCTURE

A semiconductor structure is provided. The semiconductor structure includes a first low dielectric constant (low-k) layer, a first metal layer, a metal cap layer, a dielectric on dielectric (DoD) layer, an etch stop layer (ESL), a second low-k layer, a metal via and a second metal layer. The dielectric constant of the first low-k layer is less than 4. The first metal layer is embodied in the first low-k layer. The first low-k layer exposes the first metal layer. The metal cap layer is disposed on the first metal layer. The DoD layer is disposed on the first low-k layer. The etch stop layer is disposed on the metal cap layer and the DoD layer. The second low-k layer is disposed above the etch stop layer. The metal via is embodied in the second low-k layer and connected to the first metal layer.