| 摘要 |
PROBLEM TO BE SOLVED: To avoid a leveling error in a scan type stepper by, at measuring flatness for examining an exposure focal point plane with a semiconductor substrate tilted, measuring the flatness of the semiconductor substrate for each measurement unit region whose area is that of an exposure unit region or less. SOLUTION: An exposure unit region has a horizontal length X mm and vertical length Y mm, while a measurement unit region is a region S21 having a horizontal length L1 mm which is a scanning direction for scan exposure and a vertical length L2 mm. LTV-measurement is performed for each measurement unit region S21 to determine a leveling reference plane for each measurement unit region S21, and the measurement unit region is sequentially shifted from S21a to S21b, and then to S21c for measurement likewise, determining a leveling reference plane. Related to shifting of measurement unit region, the measurement unit regions S21a and S21b, for example, as well as S21b and S21c, are performed to overlap by at least 1/2 of horizontal length. Thus, a high-precision leveling control is provided. |
