| 摘要 |
PROBLEM TO BE SOLVED: To select a sample short with ease and in a short time, and to exclude a skip shot in advance when performing alignment by EGA(enhanced global alignment) method. SOLUTION: A regular N-vertex polygon 23 inscribed in a circle 22 of a radium R from the center 25 on a wafer 4 is set, and N-pieces of shot areas containing the vertex of the regular N-vertex polygon 23 are assumed as the first candidate for a sample shot. It is judged whether wafer marks 18X and 18Y of X-axis and Y-axis of the first candidates are within the circumference 22, and with the assumption that the first candidate is possible to be focused and, at the same time, the wafer mark is also possible to be focused if both are within the circumference 22, the first candidate is selected as a sample shot. In short, if, for example, the wafer mark is not within the circumference 22 as of the first candidate 24A, a shot area 21A which is positioned, by one, inside the first candidate 24A is assumed to be the second candidate for the sample shot. |
