An interconnection structure includes a non-insulator structure, a dielectric structure, and a conductive structure. The dielectric structure is present on the non-insulator structure. The dielectric structure has a trench opening and a via opening therein. The trench opening has a bottom surface and at least one recess in the bottom surface. The via opening is present between the trench opening and the non-insulator structure. The conductive structure is present in the trench opening and the via opening and electrically connected to the non-insulator structure. The conductive structure is at least separated from the bottom of the recess.