| 摘要 |
PURPOSE:To accurately detect a position by using two areas such as an area where regularly reflected and scattered light generated from the edge of a pattern other than a mark is detected and an area where a luminous flux having the positional information of an object is detected in the case of detecting the relative position of the object. CONSTITUTION:The outside form of the mark 21 on a mask 18 surface and a detection area by a detector 1 are different. Namely, cutting is symmetrically and obliquely performed by taking a center line 21a as a boundary on the end of the projecting part of a linear zone plate 21, and the incident luminous flux B1 includes a mask normal and is made incident on the mark 21 at an angle phi with respect to the normal on a plane perpendicular to a positional deviation detecting direction. The detector 1 receives diffracted light B2 projected on the incident luminous flux side with respect to the normal on the incident surface of the luminous flux B1. In the case, since the end of the projecting part is obliquely cut, the regularly reflected and scattered light from the end 12 does not advance on the incident surface except the normal direction. Thus, the regularly reflected and scattered light is not received near the center of the detector 1 arranged at the position where the diffracted light B2 advancing on the incident surface is received and SN ratio is improved. |
