| 摘要 |
PURPOSE:To enable the slip and the gradient in the Z axial direction on the reflection surface to be monitored per shot by a method wherein Michelson's interferometers are respectively arranged in X, Y, Z axial directions on a stage to mount a semiconductor wafer and mobile mirrors perpendicularly opposing to the laser beams oscillated from respective interferometers are fitted to the stage. CONSTITUTION:Mobil mirrors 2-5 are fitted to the side of a stage 1. Next, Michelson's laser interferometers 6, 8 are arranged on the perpendicular surfaces of X Z of the mobile mirror 2 while the Michelson's laser interferometers 7, 9 are arranged on the perpendicular surfaces of X Z of the mobile mirror 3. Through these procedures, in order to contact-project the pattern on the semiconductor wafer 10 on a stage 1, the gradient and the slip of the stage 1 can be constantly monitored thereby enabling the mechanical error due to aging, etc., in the device to be corrected. |
