| 摘要 |
PROBLEM TO BE SOLVED: To provide a perimeter correcting method which can reduce a variation in the perimeter after the correction. SOLUTION: This perimeter correcting method includes a first step of correcting the perimeter of a first group of rings based on an initial elongation level and then measuring the perimeters as the first corrected perimeter, determining the average of the perimeters as a first average, determining the difference of the average from a desired perimeter to provide a first perimeter difference, and adding the correction level based on the first perimeter difference to the initial elongation level to determine a first correction elongation level, and a second step of correcting the perimeter of a second group of rings based on the first correcting elongation level, determining second corrected perimeters on the assumption that the perimeter has been corrected based on the initial elongation level, determining the average of the perimeters as a second average, determining the average of the first and second averages to provide a total average, determining the difference of the total average from the desired perimeter to provide a second perimeter difference, and adding the correction level based on the second perimeter difference to the initial elongation level to provide a second correction elongation level. The second average is obtained by subtracting the correction level based on the first perimeter difference from the average of corrected perimeters of the second group of rings which have been corrected based on the first corrected elongation level. The second step is repeated. COPYRIGHT: (C)2004,JPO
|
