An interconnection structure includes a non-insulator structure, a liner layer, a dielectric structure and a conductive structure. The liner layer is present on the non-insulator structure and has an opening therein. The dielectric structure is present on the liner layer. The dielectric structure includes a via opening therein. The conductive structure is present in the via opening of the dielectric structure and electrically connected to the non-insulator structure through the opening of the liner layer. At least a portion of the conductive structure tapers along a direction from the non-insulator structure to the dielectric structure.