A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a redistribution layer (RDL) module, a first semiconductor module, an interconnection module, a second semiconductor module and a molding material. The first semiconductor module is disposed on the RDL module. The interconnection module is disposed on the RDL module. The second semiconductor module is disposed on the interconnection module. The molding material covers the RDL module and surrounds the first semiconductor module and the second semiconductor module. A top surface of the first semiconductor module and a top surface of the second semiconductor module are exposed by the molding material.