| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of measuring overlay by which high-accuracy overlay measurement, in which the minute positional deviations of markers provided on an upper layer and a lower layer are calculated by using image processing technology, can be performed easily and surely even when the shapes of the edges of the markers are affected physically or optically. SOLUTION: On the lower layer 1, a plurality of first markers 11 having level differences are formed in, for example, scribing areas (not shown in the figure) along the four edges of the layer 1 (in the figure, two markers are formed along one edge) so that the markers 11 become symmetrical to each other in both horizontal and vertical directions. On the upper layer 2, one marker 12 is formed along the four edges of the layer 2. The first markers 11 become inner markers and the second markers 12 become outer markers. COPYRIGHT: (C)2003,JPO |
