| 摘要 |
PURPOSE:To improve precision in a picture drawing process by a method wherein the deviation of a beam axis in a direction vertical to the plane of reference is determined on the basis of the difference between a mark-to-mark distance and a reference value and the results thus obtained are used to control a deflector that in turn regulates the beam position on the material. CONSTITUTION:To determine the deviation of a beam axis prior to pattern drawing, a deflector 6 performs a digital scanning, by using the center of deflection of the beam, of each mark on a reference board 1X (or 1Y) positioned on a side of the unit. Electrons reflected by the marks are detected by a detector 10 and then sent to an arithmetic circuit 12 via a wave-form restoring circuit 11, for the determination of mark positions. When the distance between marks M1 and M2 is L and the reference board 1X is inclined by an angle theta, the beam axis is deviated by an angle alpha when it illuminates the mark M2 displaced by a distance of Lcostheta. The data thus obtained are processed in a CPU5 which determines the deviation alpha in the direction X. Deviation beta that is a vertical or Y-direction deviation is also determined in the same way. |
