Patent ID: 8022560
Filing Date: 2011-09-20
Classification: H01L

Abstract:
1. An overlay mark, applicable in a non-volatile memory, the overlay mark comprising: 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, disposed in a substrate, wherein the first X-direction isolation structures and the first Y-direction isolation structures are arranged to a first rectangle, 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, and the first rectangle and the second rectangle are separated from each other; a first dielectric layer, disposed on a surface of the substrate; a conductive layer, disposed on the first dielectric layer; a second dielectric layer, conformally disposed on the substrate; and a rectangle pattern, disposed on the second dielectric layer, wherein all sides of the rectangle pattern are located right above the second X-direction isolation structures and the second Y-direction isolation structures, respectively.