OVERLAY KEY HAVING PLURAL INTERSECTIONS AND METHOD OF MEASURING OVERLAY USING THE SAME FOR ACCURATELY MEASURING OVERLAY OF FINE PATTERN BY USING PLURAL MAIN SCALES AND PLURAL VERNIERS

摘要

PURPOSE: An overlay key having plural intersections and a method of measuring an overlay using the same are provided to measure accurately an overlay of a fine pattern by using plural main scales and plural verniers. CONSTITUTION: An overlay key includes a plurality of main scales and a plurality of verniers in order to form a plurality of intersections on a plane. The main scales are formed with a first main scale(50a) and a second main scale(50b). The verniers are formed with a first vernier(60a) and a second vernier(60b). The first and the second main scales are separated from each other. The first and the second main scales are formed with rectangular patterns extending to predetermined directions, respectively.