Patent attributes
A method of manufacturing an overlay mark is provided. Two first X-direction isolation structures, two first Y-direction isolation structures, two second X-direction isolation structures, and two second Y-direction isolation structures are formed in a substrate, where the first X-direction isolation structures and the first Y-direction isolation structures are arranged to a first rectangle, and the second X-direction isolation structures and the second Y-direction isolation structures are arranged to a second rectangle. The second rectangle is located in the first rectangle. A first dielectric layer and a conductive layer are formed sequentially on the substrate. A planarization process is performed to remove a portion of the conductive layer till the isolation structures are exposed. A second dielectric layer is formed on the substrate. A rectangle pattern is formed on the second dielectric layer. The sides of the rectangle pattern are located above the isolation structures.
