| 摘要 |
PURPOSE:To perform the good focusing operation of the title apparatus even when a spherical aberration is caused in a projection optical system. CONSTITUTION:The title apparatus is provided with the following: focal-position detection systems 15, 19, 20, 21 which find the focal position of a projection optical system PL by using a reference pattern 18 on a wafer stage WS; a bar-code reader 22 to which the line width of a pattern on a reticle R is input; a spherical-aberration operation device 11 which fins the change amount of the spherical aberration of the projection optical system PL; and a focal-position correction device 14 which corrects the focal position, of the projection optical system PL, which has been found by means of the focal-position detection systems on the basis of the line width of the pattern on the reticle R and of that of the reference pattern and on the basis of the change amount of the spherical aberration. |
