A structure, a semiconductor device and a manufacturing method thereof are provided. The structure includes a core layer and a build-up stack disposed on the core layer. The core layer includes a first core dielectric layer, a second core dielectric layer, through vias, and a patterned conductive plate. The second core dielectric layer is disposed on the first core dielectric layer. The through vias cross the first core dielectric layer and the second core dielectric layer. The patterned conductive plate is disposed on the first core dielectric layer and is electrically insulated from the through vias. The build-up stack includes interconnected conductive patterns electrically connected to the through vias. A bottom surface of the patterned conductive plate is coplanar with an interface of the first core dielectric layer and the second core dielectric layer.