Method of manufacturing mark

A method of manufacturing a mark, comprising:

• providing a substrate, wherein the substance comprises a device area and a mark area;
• forming a dielectric layer on the substrate;
• forming a dual damascene opening in the dielectric layer of the device area, wherein the dual damascene opening comprises a first opening and a second opening connected to each other, the second opening is located above the first opening, and a width of the second opening is greater than a width of the first opening;
• forming a third opening in the dielectric layer of the mark area, wherein the third opening and the first opening are simultaneously formed by a same process;
• forming a barrier material layer on a surface of the dual damascene opening and on a surface of the third opening, wherein the barrier material layer seals the third opening to form a void in the third opening;
• forming a metal material layer on the barrier material layer, wherein the metal material layer is filled in the dual damascene opening;
• and
• removing the metal material layer and the barrier material layer outside the dual damascene opening and outside the third opening to form a first barrier layer and a dual damascene structure in the dual damascene opening, and to form a second barrier layer in the third opening.