OVERLAY KEY AND MANUFACTURING METHOD THEREOF AND METHOD FOR MEASURING OVERLAY USING THE SAME

摘要

PURPOSE: An overlay key is provided to measure a degree of overlay under a manufacturing process without an SEM(Scanning Electron Microscope). CONSTITUTION: An overlay key(200) comprises a mother ruler(20) having sub-overlay patterns(300) and a son ruler(25). At this point, the shapes of the son ruler(25) and the mother ruler(20) are able to be variously embodied. At this point, portions(21) between the mother ruler(20) and the son ruler(25) are used for measuring a degree of overlay, that is, a degree of misalign between a pre-step thin film and a post-step thin film. At this point, the edge portions(22) of the mother ruler(20) have a number of sub-overlay patterns(300) for measuring the degree fo the overlay between the mother and son rulers(20,25) at the edge portions.