| 摘要 |
PURPOSE:To correct a telecentric state extremely accurately in an arbitrary position by a method wherein the telecentric state is measured and corected at an alignment position. CONSTITUTION:A detection signal corresponding to an edge part of each alignment mark is detected both in an X direction and in a Y direction as the intensity of light corresponding to a scanning position; relative positions of a reticle mark RM and a wafer mark WM are detected. A deviated amount X in the X direction out of mutually deviated amounts of the mark RM and the mark WM in a horizontal direction is obtained; in the same manner, Y as a deviated amount in the Y direction is obtained. An error from a previously established prescribed telecentric state is calculated individually with regard to both the X direction and the Y direction. On the basis of this calculated value, an angle of a halving mirror 22 is controlled both in a sagital direction and in a meridional direction of a field of view of a projection lens 12 via an encoder; the prescribed telecentric state is corrected. By this setup, the telecentric state can be corrected extremely accurately. |
