| 摘要 |
PROBLEM TO BE SOLVED: To set an object plane accurately at a predetermined position by constituting a light source section appropriately when plane position information is detected at a plurality of measuring points on the object plane by oblique incident method and adjusting the intensity of light at the plurality of measuring points commonly thereby detecting the position of the object plane precisely. SOLUTION: Plane position state of a wafer 4 mounted on a wafer stage 700 is measured in the direction of the optical axis of a projection optical system 2 by oblique incident method using a plane position detector having elements 10-110. The plane to be detected, i.e., the wafer surface, is irradiated with a luminous flux from an oblique direction and the incident position of reflected luminous flux on a specific plane is detected by a position detecting element and then the positional information of the plane to be detected in the direction of the optical axis is detected therefrom. On the other hand, a plurality of luminous fluxes, being set in a substantially specified direction, are projected to a plurality of measuring points on the plane to be detected and the information of inclination of the plane to be detected is calculated using the positional information in the direction of the optical axis obtained at each measuring point. |
